ISSN 0031- 0204

Transactions and Proceedingsof thePalaeontological Society of Japan
New SeriesNo. 151

Pa laeontological Society of Japan
October 31, 1988

Co-Editors

Hisayoshi IGO and Tsunemasa SAITO

Editorial Board: Yoshikazu HASEGAWA, Itaru HAYAMl, Hisayoshi IGO (chief), Makoto KATO,
Itaru KOlZUMl, Yasumochi MATOBA, Kei MORl, Hiroshi NODA, Kazunari TANABE,
Tsunemasa SAITO, Kazuhiko UEMURA, Akira YAO
Officers for 1987-1988
President: Tatsuaki KIMURA
Honorary President: Teiichi KOBA YASH I
Councillors: Kiyotaka CHINZEI, Takashi HAMADA, Yoshikazu HASEGAWA, Itaru HAYAMI,
HisayoshiIGO, Junji ITOIGAWA, Tadao KAMEl, Tatsuaki KIMURA, Tamio KOTAKA,Kei MORl, Ikuwo OBATA, Tsunemasa SAITO, Yokichi TAKAYANAGI, Kazushige
TANABE, Toshimasa TANAIMembers of Standing Committee: Kiyotaka CHINZEI (Membership), Takashi HAMADA (Foreign Affairs), Itaru HA YAMl (Finance), Hisayoshi IGO (Co-Editor of Transactions),
Ikuwo OBATA (General Affairs), Sumio SAKAGAMI (Co-Editor of Special Paper),Kazushige TANABE (Planning), Yokichi TAKAYANAGI (Editor of "Fossils"), Juichi
YANAGIDA (Co-Editor of Special Paper)
Secretaries: Katsumi ABE (Planning), Takeshi ISHIBASHI (Special Paper), Kunihiro ISHIZAKI("Fossils"), Tomoki KASE (General Affairs and Membership), Hiroshi NODA (Editorof Transactions), Terufumi OHNO (Membership), Tatsuo On (Planning), Kazuhiko
UEMURA (General Affairs), Toshiyuki YAMAGUCHI (Finance)
Auditor: Noriyuki IKEY A

The fossil on the cover is Vicarya yokoyamai Takeyama, an Early Middle
Miocene gastropod from the Kurosedani Formation at Kakehata, Yatsuo-cho,
Nei-gun, Toyama Prefecture, central Japan (Collected by T. Kotaka and K.
Ogasawara, IGPS No. 99075, photo by S. Ohtomo and Y. Kikuchi, xO.9).

All communication relating to this journal should be addressed to the

PALAEONTOLOGICAL SOCIETY OF JAPAN% Business Center for Academic Societies,
Yayoi 2-4-16, Bunkyo-ku, Tokyo 113, Japan

Trans. Proc. Palaeont. Soc. Japan, N.S., No. 151, pp. 501-522, 21 Figs., October 31,1988

861. EARLY JURASSIC PLANTS IN JAPAN.
PART 8. SUPPLEMENTARY DESCRIPTION AND
CONCLUDING REMARKS*TATSUAKI KIMURA,TAMIKO OHANAandMASANORI TSUJIITokyo Gakugei University, Koganei, Tokyo 184

Abstract. This is the last (8th) of our serial papers. It deals with the supplementary
description of newly obtained fossil plants and gives concluding remarks on the Early Jurassic
plants in Japan. Based on the floristic composition, we recognized the Kuruma-type andNishinakayama-type floras in late Early Jurassic time in Japan. The Nishinakayama-type flora isunique and exotic and there is no comparable flora in Eurasia. The Kuruma-type flora in Japanis similar in the floristic composition to coeval or nearly coeval floras in South China. In
addition, we briefly reviewed Early Jurassic floras in Eurasia from a paleophytogeographicalpoint of view. The taxa described in this paper are Gleichellites ? sp. A, Phlebopteris sp. A,
Dictyophyllum kotakiellse Kimura et Tsujii, Sphenopteris sp. H, Ptilophyllum shinadalliellse
Kimura et Tsujii, P. sp. cf. P. hsiallgshallellse Wu, P. sp. A, Pterophyllum ? sp., Pseudoctellis
Ilipponica Kimura et Tsujii and Nilssonia sp. B from the Kuruma Group, and Sphellopteris sp.
G, Otozamites sp. C and Pseudoctenis? sp. from the Nishinakayama Formation.

Forewordtion (Kobayashi et aI., 1957; Goto, 1983) andhas been thought to be barren of fossils. Recently, Goto (1983,1986) found the sterile leavesof Onychiopsis elongata (Geyler) Yokoyama(identification made by Kimura), with uncertain
affinity, from the Mizukarnidani Formation. The
first occurrence of Onychiopsis which is an
important element of younger Mesozoic floras inJapan, has been recognized in the lower part of
the Middle Jurassic Utano Formation bearing
younger Mesozoic-type plants, and these
Onychiopsis-bearing formations overlie conformably both the Nishinakayama Formation(Kimura et at., 1986; Kimura and Ohana, 1987a,b) and Otakidani Formation, respectively. Therefore, the stratigraphical boundary between theolder and younger Mesozoic floras in Japan isconsidered to lie between the Shinadani and
Mizukamidani Formations in the Hida Massif

This is the last (8th) of our serial papers
devoted to the Early Jurassic plants in Japan. It
deals with the supplementary description offossil plants newly obtained from the Shinadaniand Negoya Formations, Kuruma Group and the
Nishinakayama Formation, Toyora Group. Our
concluding remarks regarding the late Early
Jurassic floras in Japan and comparison of themwith those of other regions of Eurasia are
included.
Table 1 shows the stratigraphical sequence ofJurassic and Lower Cretaceous strata in Japanand their correlation between different sedimentary basins. The Mizukarnidani Formation,
the uppermost unit of the Kuruma Group overlies conformably the marine Otakidani Forma*Received May 8, 1987; revised manuscript
accepted August 1, 1988
501

Vl

Table 1.

r

Inner Zone of Japan
ToyoraDistrict

Geologicalage

Okayama
Pref.

Hida Massif~ Kf

Southern Kitakami
MassifJoetsuDistrict

10

Q)
'-

u

~K~
'-

Barremian

Shimonoseki
F.

E
c
10
::.:::.~£.

Wakino F.

aBerriasian

Yoshimo F.

Tithonian

-?-

-

<!:i
(/) £
·c

~

Tokurazawa F;'

Akaiwa F+

(/'I

~

~

f--?Oguchi F.";§

Kiyosue F.+

Isokusa F.

(!)

Oxfordian

?-

(/'I

~

BajOCian

::J

--")

Aalenian
Toarcian
Pliensbachian
Sinemurian~ettangian'------

F."

I--

10

a'I--?>.
- - -- --------a !?----- -Yamaoku-.

Higashinagano F..

~ Nakano::J sawa F.

F..

Mizukamidani F.

? - -x·c.:;(!'j Otakidani F.
Sh,'nada-m:- ~.- Iwamuro
10
F'
Teradani F.

E?-

c: Yamagami

10

10

0-

E

-x

::J

I....

Negoya F.'"::J::.::: K;tamatadani F

~

-?- ~
:::J
.~

...c::

U)

Jogodani F.

- --q

F.

Awazu F.
Tsukinoura ~

F.

?-

(!)

yama F."-?-~c!). Tomizawa

Utano F."I- Nishinaka-

::s::

F.

Kogoshio

Ishiwariloge F.

Kuzuryu G:>f.·

Bathonian~

Koyamada

~

<1l
.....

<!)

"",.....

:::J
1:
V)
(/'I
E Tochikubo 0
Oginohama
1: Mone F." (!)
.~
~ F"
(/)
F.'"
10 -"-?-

Callovianu

Ayukawa F."

a'- F."

Kimmeridgian

.iii

~

Kawaguchi (Kj), and Yatsushiro F. (Kf)

f--?-

(!)

Valanginian
K\

c:

,10

Todai F.(Kf), Yuasa, Arida and Nishihiro F.
(K\-KO, Tatsukawa, Hanoura and Hoji F.
(K\-Kf), Ryoseki and Yunoki F. (K\-Kf),

Kiladani F.-c:a

Hauterivian

10

w

Soma
District

Choshi G. (K\ -K~), Sebayashi F. (K~),<!:i
Aptianu

tv

Outer Zone of Japan

AlbianaQ)oJurassic and Early Cretaceous plant-bearing formations in Japan. Formations or groups of marine origin are marked in italics; all others of nonmarine origin. Asterisks denote plant-bearing formation or group. See text for p-q. Thick solid line (r-s) indicates the boundary between the
Inner and Outer Zone floras ranging in age froin Late Jurassic to Early Cretaceous.

Hatsuno F.

~s861. Early Jurassic Plants, Part 8(roughly late Toarcian-early Aalenian time as
indicated by a broken line p-q in Table 1). The
occurrence of other plant-taxa is likely to bemade from the Mizukamidani Formation in
future studies.
Thus, the Kuruma and Toyora Groups represent a very important part of the geologic
sequence to know the chronological change offossil plants during Early Jurassic-early Middle
Jurassic times.
Few fossil plants known from the Shizugawa
Group and the Higashinagano Formation of the
Toyora Group are not worthy of our further
discussion.
Supplementary description
Fossil plants from the Kuruma Group
Filicales
G!eicheniaceae
Genus Gleichenites Seward, 1926
Gleichenites ? sp. A
Figures 3a-b, 18a-b

Material: SRI-129 and 17 other specimens.
Horizon: Shinadani Formation.
Locality and occurrence: Shinadani (seeKimura and Tsujii, 1980a); rather rare.
Description: Many fertile penultimate pinnae
detached possibly from two large tripinnate
leaves are obtained. No whole leaf is known.
Main axis, although not in organic connection, is
thick, and is 2 cm wide. Penultimate pinnae
preserved are more than 12 cm long and 8 cm
wide, possibly lanceolate in form, with thickaxis, up to 3 mm wide. Ultimate pinnae areclosely or sometimes rather remotely set,elongate-triangular in outline, typically 3 cm longand up to 6 mm wide near the base, attachedalternately to the penultimate pinna axis at aright angle, but at a wider angle distally. They aresometimes falcate, typically sending off 27
katadromic pairs of pinnules at a wide angle.
Pinnu1es are regu1arly segmented, set closely,
rectangu1ar or triangular in form with rounded or
obtusely pOinted apex, attached to the pinna axis503

by the whole base, typically 2.5 cm long and up
to 1.5 mm wide. Midnerve is distinct, persisting
to the tip; laterals are invisible. Sori (?) aresuperficial, circular in form, about 0.3 mm indiameter; 7 pairs of them are arranged on bothsides of the midnerve. Details of sori (?) are
unknown because of their poor preservation.
Remarks: These leaves are characterized byhaving small-sized pinnules with circu1ar sori (?)
which are arranged regu1arly on both sides of
midnerve. Owing to the poor preservation of sori(?), we could not establish precisely the genericaffinity of our leaf. However, our leaves remind
us of the gleicheniaceous plant because of their'
thick main and penultimate pinna axes andperpendicularly disposed u1timate pinnae. Therefore, we identified provisionally them as
Gleichenites ? sp. A.
Gleichenites ? sp. described by Kimura andOhana (1987a) from the Nishinakayama Formation (Loc. no. 068) differs from the present
Gleichenites ? sp. A in having semi-circularpinnules. It is unfortunate that the botanicalaffmity of such finely preserved leaves can not beestablished more precisely.
Matoniaceae
Genus Phlebopteris Brongniart, 1836
Phlebopteris sp. A
Figures 1a-g, 10a-e
Phlebopteris sp. A: Kimura and Tsujii, 1981, p. 187, pI.
30, fig. 1; text-figs. la-b.

Additional material: SRI-On and 41 otherspecimens. Horizon: Shinadani Formation.
Locality and occurrence: Shinadani (see Kimura
and Tsujii, 1980a); locally common, but fragmental.
Description: Kimura and Tsujii (1981) described Phlebopteris sp. A on the basis of four
pinna fragments from the Negoya Formation.
Subsequently, Tsujii collected many additional
specimens from the Shinadani Formation. The
main rachises are mostly 1 cm wide, sending off
terminally two short arms. In the specimen
shown in Fig. lOb (or Fig. la), a basal arm sends

504

Tatsuaki KIMURA et al.

off sterile pinnae of which four are preserved;
they are more than 8 cm long; pinna axis is 2 mm
thick with a broad median ridge, and sends off
alternately disposed pinnules laterally, mostly ata right angle to the axis. Sterile pinnules areclosely set, but not in contact laterally; adjacentpinnules are connected by a distinctive web, 1-2
mm wide. Sterile pinnules are 0.5-0.75 cm wide
near the base and more than 2.5 cm long a't the
middle of pinna. They become shorter, triangularor semi-circular near the base of pinna. Midnerve
is distinct both in sterile and fertile pinnules; insterile pinnules, it gives off laterals forking at
once forward and backward branches which join
those of adjacent branches to form primaryarches (or meshes). The primary arches areusually wider than height, never including any
branch veins. The primary arches send off one or
two branch veins to form secondary arches on
the acroscopic side, and successively to form
third arches in a similar way on the basiscopic
side. Arches (or meshes) become smaller in size
and irregular in' form toward the margin ofpinnules. Each final arch sends off one or twoouter veins running nearly transversely to themargins. These outer veins are simple or occasionally forking once. Secondary and third arches(or meshes) are often invisible. Basal web connecting adjacent pinnules contains a few forward
and backward running veins close to the pinna
axis.
Fertile pinnae send off long and narrowpinnules alternately and remotely, more than 2.2
cm long and 2.5 mm wide as shown in Figs.
1f -g. Lateral veins of fertile pinnules are indistinct and details of fructification are invisible.
Remarks: Although many additional fertile
specimens were obtained, we could not clearly
determine their reproductive character. However,
it is certain that our Phlebopteris sp. A is
distinguishable in its venation of sterile pinnules
from P. polypodioides Brongniart, P. woodwardi
Leckenby and P. dunkeri (Schenk) Schenk redescribed in detail by Harris (l961) on the basisof the Yorkshire material.
Harris (1961, 1980) discussed the systematic
position of Phlebopteris (Laccopteris), Mato·nidium and Matonia mainly on the basis of
their reproductive organs. So far as the venationof our sterile pinnule is concerned, there is little
possibility that our leaves belong to Matonia.

Dipteridaceae
Genus Dictyophyllum Lindley et Hutton, 1834
Dictyophyllum kotakiense Kimura et Tsujii
figure 11
Dictyophyllum kotakiense Kimura et Tsujii: Kimura andTsujii, 1981, p. 192, pI. 30, figs. 9-11; text-figs.
4a-g.

Additional material: SID-056 and 12 otherspecimens. Horizon: Shinadani Formation.
Locality and occurrence: Shinadani (see Kimura
and Tsujii, 1980a); locally common.
Remarks: Many additional sterile leaffragments were obtained from the Shinadani
Formation. Of these specimens, a small-sized leaf
referable to this species is illustrated here.

Unclassified fern
Form-genus Sphenopteris Sternberg, 1825
Sphenopteris sp. H
Figures 2a-b

Material: SHI-178, 180, 201, 205. Horizon:
Shin ad ani Formation. Locality and occurrence:
Shinadani (see Kimura and Tsujii, 1980a); rare.
Description: A large leaf-fragment and several
small leaf-fragments were obtained. Leaf ispossibly tripinnate. Main rachis is 5 mm wide at
the preserved base, sending off penultimate
pinnae sub oppositely at intervals of 2.3 cm andat an angle of 70 degrees; they are all incomplete,
more than 8 cm long, laterally overlapping witheach other. Ultimate pinnae are set closely, morethan 15 katadromic pairs on a thick penultimate
pinna axis at an angle of 50 degrees. Acroscopic
basal pinna is longer than others and is arranged
at a wide angle to the penultimate pinna axis.
Typical pinnae are elongate-triangular in form, 2
cm long and up to 0.5 cm wide, and send off 9
pairs of pinnules at an angle of about 30 degrees.

861. Early Jurassic Plants, Part 8

c
C

505

2cm

2a

Figures 1-2. (All in natural size unless otherwise indicated).
la-g. Phlebopteris sp. A. la-d; sterile pinnae. Ie; enlarged from lc to show the venation. H-g; fertile pinnae (alldrawn from SHI-072).
2a-b. Sphenopteris sp. H. 2a; a large-sized sterile leaf (drawn roughly from SHI-178). 2b; drawn partly from 2a toshow a detailed form of pinnules and venation.

Tatsuaki KIMURA et al.

506

Pinnules are closely set to the very slender pinna
axis, rhomboidal in form, typically 4 mm longand 2 mm wide; laminae are often contiguouswith each other. Margins are shallowly serrated in
the proximal pinnules, but entire in the apicalones; serration is directed forward, typically 4pairs and with obtusely pointed apex. Venation
is rather of the Sphenopteris-type; mid nerve
persists to the tip, sending off katadromicallysimple laterals at a narrow angle; each ser~ation
receives a simple lateral vein. No pinnule is foundon the main rachis between adjacent penultimate
pinnae or on the penultimate pinna axis between

adj acent ultimate pinnae.
Remarks: The present leaf is characterized byits large size with thick main and penultimate
pinna axes and with very thin pinna axis, by theacroscopic basal pinnae at a wide angle to thepenultimate pinna axis, and by the rhomboidal
pinnules with a small number of simple lateralveins.
It is highly probable that the present leaf is
specifically distinct, but, because of its poor
preservation, we refrain from giving it a new
specific name other than classifying it as
Sphenopteris sp. H.

3b~

~5

O.05cmL-----.>

9

Figures 3-9. (All in natural size unless otherwise indicated).
3a-b. Gleichenites ? sp. A. 3aj a fertile leaf-fragment (drawn from SHI·l72). 3bj a sorus (?) enlarged (drawn
from SHI-l72).
4. Sphenopteris sp. G; a broken fern-like penultimate pinna (drawn from NI-G 1).
5. Pseudoctenis ? sp.; a single detached pinna (drawn from NI-I006).
6. Otozamites sp. C; a leaf-fragment (drawn from NI-IOOl).
7. Pterophyllum ? sp.; drawn from NNW-869.
Sa-b. Ptilophyllum sp. cf. P. hsiangshanense Wu. Saj a leaf-fragment (drawn from NNW-878). Sbj partly enlarged
from 8a to show the venation.
9. Pseudoctenis nipponica Kimura et Tsujii; drawn from SHI-133.

861. Early Jurassic Plants, Part 8

Unfortunately, we could not photographicallyillustrate the present leaves, because they were
preserved as faint impression on the bedding
plane of black shale.
Bennettitales
Genus Ptilophyllum Morris, 1840
Ptilophyllum shinadaniense Kimura et Tsujii
Figures 19a-c
Ptilophyllum shinadaniense Kimura et Tsujii: Kimura
and Tsujii, 1982, p. 270, pI. 41, figs. 5-6; text-figs.
7a-c.

Additional material: SRI-080 and 12 otherspecimens. Horizon: Shinadani Formation.
Locality and occurrence: Shinadani (see Kimura
and Tsujii, 1980a); locally common.
Additional description: Leaf is fairly long,more than 16.5 cm long, elongate-lanceolate (ornarrowly lanceolate) in outline, up to 4 cm wide,
bearing more than 56 alternate pairs of pinnae(Fig. 19c).
Remarks: Kimura and Tsujii (1982) established this species on the basis of three leaffragments from the Shinadani Formation. Recently, Tsujii collected many additional specimens referable to this species. The occurrence of
this species is therefore no longer as rare as
formerly stated and can be common locally.
Based upon those newly obtained leaves, theleaf-size (width) ranges from 1 cm to 4 cm attheir widest portion and the pinna-size ranges
from 1.2 cm x 2 mm to 2.5 cm x 3-4 mm.

507

7.8 cm long, nearly parallel-sided for the mostpart, with comparatively thick rachis, 1 mm
wide, sending off 32 alternate pairs of pinnae atan angle of about 50-60 degrees. Pinnae areattached to the upper edges of rachis, rectangularor triangular in form, with truncate, obliquely
truncate or obtusely pointed apex; typically 0.65
cm long and up to 3 mm wide near the base;basal margins are straight and not decurrent, butacroscopic basal margin is sometimes slightly
contracted. Veins originate from the pinna base,
five to seven in number, arranged in parallel andend at the distal margin; they are mostly simple,
but an occasional one is once forked. Cuticle isnot preserved.
Remarks: Kimura and Tsujii (1982) described
Ptilophyllum sp. cf. P. cutchense Morris, P.
nipponicum Kimura et Tsujii, P. sp. B from the
Negoya and Iwamuro Formations and P.
shinadaniense Kimura et Tsujii and P. sp. A fromthe Shinadani Formation. The present leaf does
not agree with any of them in its pinna form andsize. Among these forms, Ptilophyllum sp. B ismost close to the present leaf, but is distinguished by its pinnae with an obtusely pointed
or broadly rounded apex and with from five tonine veins.
Our leaf resembles those small-sized leaves of
Ptilophyllum hsiangshanense originally describedby Wu (in Wu et al., 1980) from the LowerMiddle Jurassic Xiangxi Formation, Western
Hubei, China, in its pinna form, size and venation. Because we have only a single leaf fragment,
we refrain from making a full identity of our leaf
to the Chinese species and name it simply
Ptilophyllum sp. cf. P. hsiangshanense.

Ptilophyllum sp. cf. P. hsiangshanense Wu
Figures 8a-b, 13Comparable specimens: Ptilophyllum hsiangshanense Wu:
Wu et al., 1980, p. 103, pI. 15, figs. 3-5; pI. 16, fig. 1;
pI. 19, figs. 9-10a; pI. 20, fig. 7; pI. 21, figs. 5-6.

Material: NNW-878, 879. Horizon: Negoya
Formation. Locality and occurrence: Nishineiridani (see Kimura and Tsujii, 1980a); rare.
Description: Leaf so far as preserved, it is

Ptilophyllum sp. A
Ptilophyllum sp. A: Kimura and Tsujii, 1982, p. 271, pI.
43, fig. 11; text-figs. 8, 8'.

Additional material: SHI-055 and 3 otherspecimens. Horizon: Shinadani Formation.
Locality and occurrence: Shinadani (see Kimura
and Tsujii, 1980a); rare.
Remarks: Kimura and Tsujii (1982) described

508

Tatsuaki KIM URA et al.

Figures 10-11. (A ll in na tural size) .
lOa-e. Phlebopteris sp. A . lOa, c; fert ile pinnae. lOb; a broken sterile leaf (s hown by line-drawing in rig. la ).
lOd; a ster ile pinna fragment (s hown by line-drawing in Figs. l c, e). 10e; a thick main rachis (arrow) (all from
SHI-072).
11. Dictyophyllum kotakiense Kimura et Tsujii; a small-sized leaf (SHI-056).

861. Early Jurassic Plants, Part 8
Ptilophyllum sp. A on the basis of a single
specimen obtained from the Shinadani Formation. Recently, Tsujii collected four additional
leaf-fragments referable to Ptilophyllum sp. A,
but at present no addition is needed to theoriginal description.

Genus Pterophyllum Brongniart, 1828
Pterophyllum ? sp.

S09

Cycadales
Genus Pseudoctenis Seward, 1911
Pseudoctenis nipponica Kimura et Tsujii
Figures 9, 16a-b
Pseudoctenis nipponica Kimura et Tsujii: Kimura andTsujii, 1983, p. 36, pl. 12, figs. 2-3; pl. 13, figs. 2-4;
pI. 14, fig. 1; text-figs. 2a-d.

Figures 7, 1Sa-b

Material: NNW-868 (869; counter part). Horizon: Negoya Formation. Locality and occurrence: Nishineiridani (see Kimura and Tsujii,
1980a); rare.
Description: A single leaf-fragment was obtained. Its rachis is comparatively thick, 3.5 mm
wide. Pinnae are long and narrow, linear,S cm
long and 4 mm wide, gradually narrowing toward
the acuminate apex, often falcate, rather remotely set with a gap about 2-3 mm wide, andattached oppositely or suboppositely to thelateral sides of rachis by the whole base at anangle of about 55 degrees. Pinna base is slightly
expanded but not contracted near the base. Six
veins are originated at the base of pinna, simple,
parallel and end at the distal margin, but notconverging at apex. Cuticle is not preserved.
Remarks: The present leaf differs from thoseof Pseudoctenis nipponica Kimura et Tsujii
known from the Negoya and Iwamuro Formations in that the pinnae of P. nipponica become
generally narrower toward the base, often contracted near the base and sometimes markedly
expanded at the base.
Some leaves of Tyrmia latior described by Ye(in Wu et aI., 1980) from the Xiangxi Formation,
Western Hubei, China, resemble in form our leaf,
but is distinct by their shorter pinnae.
The leaves of Pterophyllum firmifolium described by Ye (in Wu et aI., 1980) and P.
decurrens by Sze (1949) also from the Xiangxi
Formation are most close to our leaf in general
aspect, but we refrain from making the genericand specific identity of our inadequately preserved leaf with either of them. Thus, we
describe our leaf simply as Pterophyllum ? sp.

Additional material: SHI-133 and 3 otherspecimens. Horizon: Shinadani Formation.
Locality and occurrence: Shinadani (see Kimura
and Tsujii, 1980a); rather rare.
Remarks: Several leaf-fragments were obtained first from the Shinadani Formation. They
are referable to those originally described by
Kimura and Tsujii (1983) as Pseudoctenis
nipponica from the Nagoya and Iwamuro Formations. Fig. 9 (drawn from Fig. 16b) shows aleaf-fragment bearing seven remotely set pairs of
pinnae; each with a small number of veins (5-6 innumber at base), forking near the base in themanner as shown in text-fig. 2b (Kimura andTsujii, 1983).

Genus Nilssonia Brongniart, 1825
Nilssonia sp. B
Figures 17 a -c, 20
Nilssonia sp. B: Kimura and Tsujii, 1983, text-figs. 7a-b.

Additional material: SHI-054 and 11 otherspecimens. Horizon: Shinadani Formation.
Locality and occurrence: Shinadani (see Kimura
and Tsujii, 1980a); locally common.
Remarks: Kimura and Tsujii (1983) described
Nilssonia sp. B on the basis of two leaffragments. Recently, Tsujii collected many additionalleaf-fragments referable to Nilssonia sp. B.
According to these newly obtained specimens,
the leaf-width ranges from 1 to 2.5 cm. Nilssonia
sp. B is not as rare as formerly mentioned, but
can be common locally.

510

Tatsuaki KIMURA et al.

17b

861. Early Jurassic Plants, Part 8

Fossil plants from the
Nishinakayama FormationForm-genus Sphenopteris Sternberg, 1825
Sphenopteris sp. G
Figure 4

Material: NI-G 1 (collected by H. Ishida).
Locality and occurrence: Ishimachi (Loc. no.
062; see Kimura et aI., 1986); very rare.
Description: A single, fern-like, penultimate
pinna was obtained. In this specimen, only 6
broken ultimate pinnae are preserved. The specimen was discovered together with an ammonite
fossil. Ultimate pinnae are closely set, overlapping with each other laterally, lanceolate inform, 1.25 cm long and up to 0.25 mm wide,
attached to the axis at an angle of 30 degrees,and send off 4 or 5 pairs of pinnules anadromically. Pinnules are lanceolate or oblanceolate inform, directed forward, typically 5 mm long and
up to 1 mm wide; margins are entire or shallowly
lobed once near the apex or rarely twice; apicesof pinnules and lobes are obtusely pointed. A
single vein originates from the base of pinnule,forking sympodially twice or in some instances
up to four times; each lobe receives a single vein.
Remarks: The present fern-like leaf-fragment
is characterized by its small-sized and anadromically dissected pinnules with the Sphenopteristype venation. Kimura and Ohana (I987a) described in detail six types of fern-like leaves with
the Sphenopteris-type venation from the Middle
Jurassic Utano Formation on the south side of
the Tabe Fault. Among these six types,
Sphenopteris sp. B is common to both Nishinakayama and Utano Formations. However, none ofthem agre~ in general morphology with thepresent leaf-fragment. Thus, we provisionally

511

identify the present leaf-fragment as Sphenopteris sp. G.
The present leaf-fragment has been thought tohave no paleobotanical value, but we endeavour
to describe even such a poorly preserved specimen, because fossil plants, especially ferns or
fern-like plants, rarely occur in the Nishinakayama Formation.
Bennettitales
Genus Otozamites Braun, 1842
Otozamites sp. C
Figures 6, 14

Material: NI-lOOI (collected by T. Fukutomi). Locality and occurrence: Ishimachi (Loc
no. 062; see Kimura et aI., 1986); very rare.
Description: A single bennettitalean leaffragment was obtained. It is more than 3 cm longand up to 5.5 mm wide and nearly parallel-sided
for the most part; rachis is comparatively thickand sends off closely and alternately disposed
small-sized pinnae from its upper surface. Pinnae
are subulate or rectangular in form, typically 3.5
mm long and up to 1 mm wide, abruptly
narrowed toward the obtusely pointed apex;
pinna base is asymmetrical, not decurrent; acroscopic basal angle is moderately developed; basiscopic basal angle is usually concealed by theacroscopic basal angle of opposite pinna. Veins
are invisible. Cuticle is not preserved.
Remarks: Judging from the general habit of
the present leaf, it is highly probable that ourleaf belongs to Otozamites or Ptilophyllum At
present, we prefer to assign it to Otozamites,
because of its moderately developed acroscopic
basal angle of pinnae.
Kimura et al. (1986) described three types of
Otozamites leaves from the Nishinakayama+- Figures 12-17. (All in natural size unless otherwise indicated).
12. Pseudoctenis? sp.; detail is shown in Fig. 5 (NI-lO06).
13. Ptilophyllum sp. cf. P. hsiangshanense Wu; enlarged twice (NNW-879).
14. Otozamites sp. C; detail is shown in Fig. 6, but veins are indistinct (NI-IOOl).
15a-b. Pterophyllum ? sp. 15a; (NNW-868). 15b; detail is shown in Fig. 7 (NNW-869).
16a-b. Pseudoctenis nipponica Kimura et Tsujii. 16b; detail is shown in Fig. 9 (all from SHI-133).
17a-c. Nilssonia sp. B; leaves of varied size (SHI-054).

512

Tatsuaki KIMURA et al.

861. Early Jurassic Plants, Part 8

Formation. Among these, the present leaf resembles those of Otozamites micropinnatus in its
small-sized leaf, but is distinguished by its shorter
pinnae.
The detailed comparison of such small-sized
Otozamites leaves was made by Kimura et al.
(1986). However, we refrain from making a
specific identity of our present leaf specimen andcall it simply Otozamites sp. C, because our leaf
is not complete to establish its taxonomic identification.
Cycadales
Genus Pseudoctenis Seward, 1911
Pseudoctenis ? sp.
rigures 5, 12

Material: NI-1Q06. Locality and occurrence:
Ishimachi (Loc. no. 064A; see Kimura et al.,1986); very rare.
Description: A single detached pinna was
obtained. It has the following features: Lanceolate in form, more than 4.7 cm long and up to 9
mm wide, apex missing and base contracted; 9 or
10 veins originating at the base, then repeatedly
forked dichotomously, radiating and ending at all
the margin except for a few median ones which
run straight for the most part, then radiating near
the apex. Cuticle is not preserved.
Remarks: It is quite difficult to determine
specific and even generic attribution of ourdetached pinna. However, our pinna resembles
externally those of Pseudoctenis oleosa described
originally by Harris (1949) from the Middle
Jurassic of Yorkshire, but its venation is fairly
different from those of the latter.
So far as we know, no pinnae comparablewith ours. have been recorded. Therefore, we
provisionally identify our pinna as Pseudoctenis?
sp.

513

Concluding remarks
Table 2 shows the list and occurrence of fossil
plant-taxa described from the Kuruma Group
including the Shinadani and Negoya Formations,
Alternating beds of sandstone and shale (Kr2),
Plant-bearing beds in the Kotaki Coal-Field,
Iwamuro Formation (Kimura and Tsujii, 1980a,b, 1981, 1982, 1983, 1984 and the present
paper) and the Nishinakayama Formation(Kimura et al., 1986; Kimura and Ohana, 1987a,b and the present paper).
A glance of Table 2 easily suggests that there
were two distinct floras in the late Liassic time inJapan, the Kuruma-type and Nishinakayama-typefloras. No species common to both floras has so
far been described.
1. Characteristic of the Kuruma-type flora.
This type of flora has been known from theKuruma Group and the Iwamuro and Yamaoku
Formations and its characteristic includes thefollowing:
Equisetales: Equisetites is varied andabundant, but Neocalamites is only represented
by a single form.
Ferns: 1) Such osmundaceous ferns as Todites
are varied and abundant, 2) Phlebopteris(Matoniaceae) leaves are abundant, especially in
the Shinadani Formation, 3) two types of dicksoniaceous ferns and four types of dipteridaceous
ferns, such as Clathropteris, Dictyophyl!um,
Thaumatopteris and Hausmannia are present, butthey are rather rare except for Dictyophyl!um, 4)
Cladophlebis leaves with uncertain affinity arevaried and abundant, and they are accompanied
by a rare presence of two types of fern leaves
with the Sphenopteris-type venation.
Pteridospermales: Only a single species of
Ctenozamites is represented.
Bennettitales: Two types of both Otozamites~ Figures IS-20. (All in natural size unless otherwise indicated).
ISa-b. Gleichenites ? sp. A. ISb; detail is shown in rig. 3a (all from SHI-129).
19a-c. Ptilophyllum shinadaniense Kimura et Tsujii. 19a; enlarged twice from Fig. 19b (SHI-OSO). 19c; alarge-sized leaf (SHI-080).
20. Nilssonia sp. B; a larger leaf (SHI-054).

514

Tatsuaki KIMURA et al.
Table 2.

List of fossil plants of the Kuruma-type and Nishinakayama-typefloras (late Liassic) in Japan. Their abundances are indicated: VA;
very abundant, LA; locally abundant, A; abundant, C; common, LC;
locally common, RR; rather rare, R; rare, VR; very rare.

~
Taxa described

Kuruma Group (s.1.)

'c

u:

'"

~

~

.,;

~u.:

'"

LA
RR
R

E. sp. CR

Neocalamites sp. A

Marattia asiatica (Kawasaki) Harris

LA
R
RR

Osmundopsis nipponica Kimura et Tsujii
Gteichenites ? sp. A

0LA

E. nipponicus Kimura et Tsujii

T. fastuosus (Kimura) Kimura el Tslujii
T. neiridaniensis Kimura et Tsuji;~

E'"" .-I~'"
1 ~~LL

e

E

LA

LA

E. sp.A
E. sp. B

Todites sp. eI. T. denticulatus (Brongniart) Krasser

~
~

z"

Equisetites iwamuroensis Kimura

E. mori-gunpe;i Kimura et Tsujii

u:

Kr,

A
VA
LA
RR

RR

LA
R

LA
R

LA
R

A

R

A
VA
R

RR

G. ? sp.

R

Phlebopteris sp. A
Ph. sp.

LC

RR
R

Coniopteris neiridaniensis Kimura et Tsujii

C. sp. A
Clathropteris meniseaides Brongniart

Oictyophyllum kotakiense Kimura et Tsuji;

RR
R
RR
LC

Thaumatopteris elongata Oishi
Hausmannia (Proforhipis)

Toyora
G.

RR
C
R

R

R
R
RR
VR
R

R

sp. A

Cladophlebis sp. d.' Asterotheca okafujii Kimura et Ohana
C. sp. eI. Todites fukutomii Kimura et Ohana
C. sp. cf. T. yamanoiensis (Yokoyama)Kimura el Ohana
C. kurumens;s Kimura et Tsujii
C. pseudodeficatufa Oishi
C. raciborsk;; Zeill ....
C. sp. A
C. sp. B
C. sp. C
Sphenopteris sp. A
S. sp. B
S. sp G
S. sp. H
Ctenozamites sarran; (Zeiller) Harris

R
VR
R
R

C
R
RR
R
RR
RR

R
R
R
RR

R

R
VR
RR
RR
VR
VR

VR
RR
VR
VR
R
VR

C. ? sp.
Anomozamites sp. A

and Pterophyllum and six types of Ptilophyllum
are present and some of them are abundant;
Zamites leaves have not been found.
Cycadales: Both Ctenis and Pseudoctenis are
represented by a single species. Nilssonia is varied
and abundant.
Unclassified cycadophyte: Represented by
Cycadites only, but it is very rare.
Ginkgoales: Five types of leaves are represented, some are common.
Czekanowskiales: Both Czekanowskia andVR
VR

Phoenicopsis are represented by a single species.
Coniferales: Elatocladus, Storgaardia and fourtypes of Podozamites are represented; all are rare
except for Podozamites ex gr. dis tans. A single
cone-scale of Sweden borgia is known. No conifer
with scale-like leaves has been known except forindeterminable shoots with minor scale-likeleaves arranged spirally on the axis as those ofextant Widdringtonia.
Unclassified plants: Six types of Taeniopteris
are represented. In addition to the above, some

861. Early Jurassic Plants, Part 8~
Taxa described515
ToyoraKuruma Group {so i.l

."'"

"'"
.J:
.~

<flU:

~
go

G.
u:

u:

ex

Kr,

Z

'"
~
0

e
~
~

R

0, micropinnatu5 Kimura, Naito et Chana

RRA

0. sp. A

R
RVR

O. sp. B
O. sp. C
Pferophy{fum ex gr. propinquum Goeppert

RR

LA

P. sp. A
P. ? sp.

R

Ptilophyllum nippon;cum Kimura et Tsujii

CP. shinadaniense Kimura et Tsujii
P. sp. d. P. cutchense Morris
P. sp. cf. P. hsiangshanense Wu
P. sp. A

R

R

RR
R

LC

R
R
R
VR

P. sp. B

R

Zamites toyoraensis Oishi

R
R

Z.sp.
Clems kaneharai Yokoyama

LC

R

Pseudoctenis nipponica Kimura et Tsujii
P. sp.

RR

LC

LC

Nilssonia japanica Kimura et Tsujii

RR

LA

LA

R
R

R

N. sp. ct. N. inoue; Yokoyama
N. sp. A
N. sp. B

R

LC

R

N. sp. C

VR

N. sp. 0

R
VR
VR

N. sp. E
Cycadiles sp. ct. C. saladin; ZeHler

Ginkgo ex gr. sIbirica Heer
Sphenobaiera nipponica Kimura el Tsujii

S. sp. cf. S. eurybasis Sze

VR
LC

LC

LC

VR

s. sp. cf. s. ophioglossum Harris et Millington

R

VR

LC

VR

Ginkgoidium ? sp. A
Czekanowskia ex gr. rigida Heer

RR

Phoenicopsis ex gr. angustifolia HeerLC

Elatocladus sp. A

R

Storgaaroia spectabiHs Harris
Podozamites ex gr. distans (Pres\) Braun

P. sp. A
P. sp. B
P. sp. C

RR

RR

C

R

sp. A

RR
RR

RR

RR

RR

LC

VR
RR

E. sp. B

Swedenborgia

Z ~u:

R

Otozamifes fuji"moto; Kimura

O. neiridaniensis Kimura et Tsujii

'E"

I~

~~

C

R
R
R
VR

Brachyphyllum ex gr. expansum {Sternberg} Seward

C

Cupressinocladus sp. A

RR

c. sp. B

undetermined organs were found. One of these ispossibly a vertically crushed bennettitalean
gynoecium (Bennetticarpon ? sp.).
Obviously, the Kuruma-type flora is a memberof the Dictyophyl!um-Clathropteris floras in East
Asia which range in age from the Late Triassic toearly Middle Jurassic. It is distinguished, however, from the Late Triassic DictyophyllumClathropteris floras known extensively fromJapan, Southern Primorye, Northeast China,
South China and Southeast Asia by the absenceof such Triassic elements as Lobatannularia,
Chiropteris, Anthrophyopsis, Drepanozamites,
Podozamites with very narrow leaves, andCycadocarpidium, and by a small number of taxa
of dipteridaceous ferns and Pterophyllum
The Kuruma-type flora is also distinguishedfrom the Middle Jurassic Vtano flora, a single

Tatsuaki KIMURA et al.

516~
Taxa described

oyora
G.

Kuruma Group (5.1.)

·c

'"
'"
E

"0

<f)LL

LL

LL

~

Kr,

I

ex

'"
~

~

E

1 .'l!n:I .
ZC:LL

R
C
LC

Geinitzia sp.

Ela/ides sp.
Araucarites sp. ct. A. cutchense Feistmantel
Taeniopteris gracilis Kimura

T. sp. ct. T. jourdy; Zeiller
T. sp. A
T. sp. B
T. sp. C
T. sp. 0

representative of this age in Japan (Kimura andOhana, 1987a, b) in the floristic composition.
The latter is characterized by the presence ofsuch younger Mesozoic elements as Onychiopsis
elongata,
Acrostichopteris,
Adiantopteris,
Zamites and Araucarites.
The Kuruma-type flora also differs from theMiddle Jurassic floras in China. The latter ischaracterized by the presence of varied andabundant dicksoniaceous ferns, varied ginkgoaleans and czekanowskialeans, and by therarity of dipteridaceous and matoniaceous ferns.
2. Characteristic of the Nishinakayam-type flora.
This type of flora has been known only
from the Nishinakayarna Formation, Toyora
Group. Despite a great deal of effort expanded
toward collecting fossil plants from this formation by Gentaro Naito and many others for morethan 30 years, taxa known from this formation
are not so numerous (Table 2).
The Nishinakayama-type flora is characterized
by the following:
1) Plants belonging to Equisetales, Marattiales
and Osmundales are not known. 2) Ferns are
only represented by Gleichenites ? sp., Phlebopteris sp., and two forms of Sphenopteris withuncertain affinity. Dicksoniaceous and dipteridaceous ferns have not been found at all. 3) Only
Ctenozamites ? sp. is known in Pteridospermales.
4) Four types of Otozamites leaves and two
types of Zamites leaves are known in Bennettitales. Other bennettita1eans have not so far beenfound. 5) Only Pseudoctenis sp. is known in
Cycadales. 6) Ginkgoaleans and czekanowskialeans are not known. 7) Four types of shoots

'"

E

.l~
.c~

LA
R

R

R

R
LA
R
VR
R
VR

with scale-like leaves, araucarian cone-scales andleafy shoots (Elatides sp.) are known in Coniferales. Podozamites-shoot has not been found.
So far as we know, there is no flora comparable with the Nishinakayama-type flora inEurasia. Although the number of the taxa of the
Nishinakayama-type flora is not so numerous, we
now think that this type of flora might haveflourished in the subtropical-tropical region in
those of the Jurassic world. This is supported by
the presence of Tethys-type ammonites in the
Nishinakayama Formation.
3. Comparison of the Kuruma-type flora with
the Early Jurassic floras in other regions ofEurasia.
Fig. 21 shows main localities of early and lateLiassic and undifferentiated Early Jurassic plants
in East Asia drawn by Kimura mainly withreference to Ye and Li (1980, 1982), Zhang(1985) and Vakhrameev (1964). However, it isdifficult to date them precisely, because most ofthese plant-beds are of non-marine origin except
for those in Japan and some in South China(Guanyintan and Jinji Formations and LantangGroup).
In Eurasia, we roughly recognized the following five types of Early Jurassic floras: I) Siberiantype, II) Kuruma-type, III) Middle Asian-type,IV) South European-type and V) Nishinakayamatype.
I) The Siberian-type floras are characterized
by: 1) the rarity of dipteridaceous ferns, bennettitaleans and cycadaleans, 2) the presence ofvaried ginkgoaleans and czekanowskialeans, and3) the absence of Ptilophyllum, Zamites and861. Early Jurassic Plants, Part 8
conifers with scale-like leaves.
The following plant-beds (or formations) belong to the Siberian-type (each number inparenthesis corresponds to that shown in Fig.
21): Daxigou (24), Xiaomeigou (25), Yangxia(27), Badaowan and Sangonghe (28), Wudanggou(29), Fuxian (31), Yongdingzhuang and Lower
Yaopo (32), Beipiao (33), Yingzi (34), Hongqi(35), Chayihe (36), Changliangzi (37), Yihe (38),Iukhtin (40), Ukugut (41), Nerejaslov (42),
Makarov (43), Karaldin, Sartakov and Tersjukov(44), Taisugan (45), Alakul (46), Ashchikul (47)and Maikuduk, Dubov and Sokur (48). Fossil
plants from Wensu locality (26) is little known.
In addition to the above, the Early Jurassic
Siberian-type floras are known from Turgai,
ChelJabinsk and eastern part of the Ural Mountains. These Siberian-type floras are distributed
to the north of the X-Y line in Fig. 21.
Dipteridaceous ferns are sparsely known in mostof these floras. In a Late Triassic time, dipteridaceous ferns are restricted in their distribution
to the Dictyophyllum-Clathropteris Paleofloristic
Province as shown by Kimura (1984a, b, 1985)
and Kimura and Kim (1984a, b). Accordingly, it
is quite certain that by an Early Jurassic time,some dipteridaceous ferns expanded their distribution northward.
Notwithstanding that the Nansuletu Group(30 in Fig. 21) located far to the north of the
X-Y line in Fig. 21, its flora is of the Kurumatype according to the floristic composition
shown by Zhang (1985). This is only a single
exceptional case in those floras distributed to thenorth of the X-Y line in Fig. 21.
II) Characteristics of the Kuruma-type floras
in Japan have already been discussed. The floraof the Yarnaoku Formation (Konishi, 1954),
although it is as yet to be described andillustrated, obviously belongs to the Kurumatype.
In South China, late Liassic floras of thefollowing plant-beds (or formations) are of theKururna-type: Baitianba (21), Xiangxi (20),
Wuchang (19), Xiangshan (7) and Majian (9).
The early Liassic Guanyintan flora (Zhou,
1984) is fundamentally of the Kuruma-type, it is517

characterized by the presence of varied Otozamites leaves and Brachyphyllum leafy-shoots
and by the absence of Ptilophyllum.
However, the Guanyintan, Tanglong, Baitianba and Xiangxi floras somewhat resemble
coeval floras of South Europe in the presence ofconifers with scale-like leaves, such as Brachyphyllum No such conifers with scale-like leaves
have been known in the Kuruma-type floras inJapan with only exception of the sparse occurrence of 'Widdringtonia'-like delicate leafy-shoots(undescribed).
We are of the opinion that the Liassic floras
from East Greenland (Harris, 1937) and South
Sweden (Lundblad, 1950, 1959) are rather of theKuruma-type.
III) Middle Asian-type floras are distributed
mostly in the mountainous region in Gissar(Hissar) and Fergana (Ferghana) Ranges,
southern part of the Ural Mountains and easternpart of the Caspian Sea (including Karatau
Range).
Barnard (1973) did not take the presence of
this type of floras seriously. However, the Middle
Asian- type floras of Early Jurassic age arecharacterized by: 1) the rarity of dipteridaceous
ferns, bennettitaleans, cycadaleans and conifers
with scale-like leaves, and 2) the presence of
dicksoniaceous ferns, varied ginkgoaleans, andFerganiella.
Although the Early Jurassic Middle Asian-typefloras resemble those coeval Siberian-type floras
in the rarity of dipteridaceous ferns, bennettitaleans and cycadaleans, they are quite distinct
from the latter in the common presence of
marattiaceous and matoniaceous ferns which arevery rare in the latter. Of these Middle Asiantype floras, however, such floras as from Tuarkyr(West Turkmen; not indicated in Fig. 21) andeastern part of the F ergana Range (51) are ratherof the Kuruma-type, because they include variedbennettitaleans and cycadaleans. Therefore, theMiddle Asian-type floras will possibly be divided
further into two floristic types in future studies.
IV) Those floras from the Lower Jurassic
plant-beds intercalated mostly with strata of
marine origin in France, Luxemburg, South518

Tatsuaki KIMURA et al.

......

30~:,;,,,,>..,,,",,.",....--+----',i.r".
.". ~....... "10- T

Late liassic(or said to be Late Liassic)'" Early Liassic(or said to be Early liassic)• Undifferentiated liassic

0---/-- 21
60

\30

I

90

100

861. Early Jurassic Plants, Part 8
Germany, Italy, Hungary and Rumania arecharacterized by the presence of such pteridosperms as Thinnfeldia and conifers with scale-likeleaves (cheirolepidiaceous conifers) plus the presence of matoniaceous and dipteridaceous ferns,
bennettitaleans, cycadaeleans and ginkgoaleans,
and the rarity of dicksoniaceous ferns, czekanowskialeans and Podozamites. We therefore
designated them as the South European-type.
V) The Nishinakayama-type flora is at present
known only from the upper Liassic Nishinakayarna Formation, Toyora Group, Japan. For the
Early Jurassic interval, Vakhrameev (1964, 1966)

519

proposed the Siberian and Indo-European Paleofloristic Areas in Eurasia. His Indo-European
Area was further paleophytogeographically subdivided by himself into European, Middle Asianand East Asian Provinces.
Our Siberian-type, Kuruma-type, Middle
Asian-type and South European-type floras
nearly correspond to those of Vakhrameev's
Siberian Area, East Asian, Middle Asian andsouthern part of European Provinces respectively.
Known fossil plants from Nroth Viet Nam(22) and Laos (23) are too few to draw any~ Figure 21. Main localities of the Early Jurassic plants in East Asia, with their sources and floristic types.
(F; formation, G; group, Asterisk; marine origin or partly marine origin)

Japan: 1. Niranohama F.* (Hettangian) (Asama, 1968) and Hosoura F.* (Hettangian-Aalenian) (Shimakura,1936), Miyagi Prefecture. 2. Iwamuro r.*, Gumma Prefecture (Kimura, 1959; Kimura and Tsujii, 1980a-b, '81,
'82, '83, '84). 3. Kuruma G.*, Niigata, Nagano and Toyama Prefectures (Oishi, 1931; Kimura and Tsujii,
1980a-b, '81, '82, '83, '84).4. Yamaoku F. *, Okayama Prefecture [Konishi, 1954 (list)). 5. Higashinagano F. *,Toyora G. [Oishi, 1940; Takahasi, 1973a-b; Takahasi and Mikami, 1975 (list)). 6. Nishinakayama F. *, Toyora
G. [Oishi, 1940 (pars); Huzioka, 1938; Takahasi, 1973a-b; Takahasi and Mikami, 1975 (list); Kimura, Naito andOhana, 1986].
South China [sources depend mainly on Zhang, Z. c., 1985 (list), unless otherwise mentioned): 7.
Xiangshan r., Jiangsu and Anhui. 8. Yuetan r., South Anhui. 9. Majian F., West Zhejiang. 10. Longpu andMaonong F., West Zhejiang. 11. Fengping r., West Zhejiang. 12. Lishan r., North rujian. 13. Lower part ofSongling G., East Guangdong. 14. Lantang G.*, East Guangdong. 15. Jinji F.*, North Guangdong. 16. Tanglong
and Maoxianling F., Southeast Jiangxi. 17. Zaoshang and Menkoushan F., Jiangxi and Hunan (Zhang, C. F.,
1985). 18. Guanyintan F., Southwest Hunan and Guangxi (Zhou, Z. Y., 1984). 19. Wuchang F., Southeast
Hubei. 20. Xiangxi F., West Hubei (Sze, 1949; Wu, S. Q. et 01., 1980).21. Baitianba f., North Hubei.
North Viet Nam: 22. Moncay (Patte, 1927, in Vozenin-Serra and Boureau, 1978).
Laos: 23. Muong-Phine (Vozenin-Serra and Boureau, 1978).
North and Northwest China [sources depend mainly on Zhang, Z. c., 1985 (list) unless otherwise
mentioned) : 24. Daxigou F., Lanzhou, Gansu. 25. Xiaomeigou F., northern margin of the Chaidamu Basin. 26.
Wensu, West Xinjiang. 27. Yangxia F., Kelasu G., northern margin of Talimu Basin, Xinjiang (Gu, D. Y., 1984).
28. Badaowan and Sangonghe F., Shuixigou G., Zhungeer and Tulufan Basins, Xinjiang (Gu, D. Y., 1984; Wu, S.
Q. and Zhou, H. Z., 1986). 29. Wudanggou F., Shiguaigou G., Yinshan, Neimeng. 30. Nansuletu G., Neimeng.
31. Fuxian F., North Shaanxi (Huang, Z. G. and Zhou, H. Q., 1980). 32. Yongdingzhuang F., Dadong, Shanxi
and Lower Yaopo F., Mentougou G., Xishan, Beijing (Chen, F. et 01., 1984; Li, B. X. and Hu, B., 1984).
Northeast China [sources depend mainly on Zhang, W. et 01., 1980 and Zhang, Z. C., 1985 (list)): 33.
Beipiao F., West Liaoning. 34. Yingzi F., Zhaowudameng, Neimeng. 35. Hongqi F., Daxinganling, West Jilin. 36.
Chayihe F., Yanjiagou G., Butehaqi, Hulunbeierqi, Neimeng. 37. Changliangzi F., Benxi, East Liaoning. 38. Yiher., Linjiang, South Jilin.
Soviet Union [sources depend mainly on Vakhrameev (1964; list) and Sixtel and Khudaiberdyev (1968),
unless otherwise mentioned). 39: Petrovka River area*, Southern Primo rye (Krassilov and Schorochova, 1973).
40. Iukhtin F., upper course of the Aldan. 41. Ukugut F., Vilui River area. 42. Nerejaslov F., Kansk Basin. 43.
Makarov F., Chulymo-Enisei Basin, northeastern part of Krasnojarsk. 44. Karaldin, Sartakov and Tersjukov F.,
Kuznetsk Basin, 45. Taisujan F., Kenderlyk Basin, eastern part of Zaisan. 46. Alakul F., near Alakul Lake. 47.
Ashchikul F., Maikjuben Basin, western part of Pavlodar. 48. Maikuduk, Dubov and Sokur r., Karagandin River
area. 49. Dzhil r., southern part of Issyk Kul Lake. 50. Kyzylsuek and Agulak F., Son Kul Lake region. 51.
Tujuk r., eastern part of rergana Range. 52. Kok-Jangak Coal-Field, eastern part of Dzhalabad. 53. Lower partof Suljuktin F., southern part of Fergana Range (Khudaiberdyev et 01., 1971). 54. Angren r., southern part of
Tashkent (Gomolitzky et 01.,1981).

Tatsuaki KIMURA et al.

520

detectable conclusion.
Notes: All specimens described in this paper
are kept in the Department of Astronomy and
Earth Sciences, Tokyo Gakugei University.
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Takahasi, E. and Mikami, T. (1975): Jurassic System in
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521

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Vozenin-Serra, C. and Boureau, E. (1978): Sur l'interetphytostratigraphiqueduBassinhouillermesozoique de Nong-Son-Vinh Phuoc dans Ie
Centre Vietnam et ses rapports avec la phylogenie
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Triassic and Lower and Middle Jurassic plants fromthe Hsiangchi Group, Western Hubei. Mem
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text', Nanjing Inst. Geol. Palaeont., A cad. Sinica.
241-253. Sci. Press, Beijing (in Chinese).
Zhang, C. r. (1985): Early Jurassic flora from Eastern
Hunan. Prof Pap. Stratigr. Palaeont., Beijing, no.
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abstract).
Zhang, Z. C. (1985): Jurassic floras. In 'Jurassic System
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no. 7, 91 pp., 34 pIs. Sci. Press, Beijing (in Chinesewith English abstract).

522

Tatsuaki KIMURA et al.

japanese names: Akaiwa iiF¥i, Arida i'iEE, Ayukawa fMJII, Choshi ~Er, Gunma llf.~,
Hanoura 3f:lOO, Hida 1fU!'I!, Higashinagano **!I!T, Hoji m~, Hosoura *IBOO, Itoshiro :fii1ri: B ,Iwamuro ¥i~, joetsu J:.~, Kawaguchi )110, Kitadani ~t:fr, Kitakami ~tJ:., Kiyosue rfIf*,
Kogoshio Ij'.q 79, Kotaki 'Ni'[, Kuruma *.~, Kuzuryu jljJi~, ~iyagi -gmt, ~izukamidani 7.kJ:.
:fr, Mone .~, Nagano *!I!T, Negoya i);!JJE:fr, Niigata ~j~, :\iranohama jili/~, :\ishihiro i1!i$, Nishinakayama i1!i9o LlJ, Oguchi ~ 0, Oginohama ~ / ~, 0 jika (= Oshika) !l±Jm, Okayama
I11rILlJ, Otakidani :klt:fr, Ryoseki ~Ji:fi, Sebayashi i:m;1%, Shimonoseki TM, Shinadani t~:fr,
Shishiori Jm:J1T, Shizugawa iti*JII, Somanakamura tl3.~9o H, Tabe EE $, Tatsukawa :lz: )11 ,Tetori -'fI&, Tochikubo W~, Todai Pi'l, Tokurazawa p;(g-'/R, Tomizawa ~'/R, Torinosu ,~/~, Toyama ~LlJ, Toyora :ROO, Utano :;fX!I!T, Wakino ~!I!T, Yamaoku LlJ~, Yatsushiro /\1-'\,
Yoshimo WID, Yuasa ~131;, Yunoki ;flb/
Chinese names: Anhui *~, Badaowan /\l!l:~, Baitianba BEE tl'l., Beijing ~tJJi:, Beipiao ~t~,Butehaqi ;fp~P€l-~, Chaidamu ~~*, Changliangzi *~r, Chayihe 1tfJtiPJ, Dadong :k[i'l],Daxigou :ki1!i~, Daxinganling :k~*iltl:, Fengping m.:PjL, Fujian m:l'l!, Fuxian ~W<, Gansu 11"j)f(i, Guangdong $*, Guangxi $i1!i, Guanyintan Wl.1fi\, Hongqi U~, Hubei (Hupeh) i'I1l~t,
Hulunbeierqi Pff$ J'l. m~, Hunan i'I1li¥l. jiangsu iIffii', jiangxi iI i1!i, jilin w;1%, jinji ~~IL
Kelasu R:1'iLffii', Lantang ~iIi!i, Lanzhou i!ili rl'l, Liaoning )!,¥, Linjiang W; iI, Lishan ~ LlJ ,Longpu ~ ~, Majian .~ il'n', Maonong -'€ ¥f, Maoxianling =$ 1m iltl:, ~enkoushan F~ 0 LlJ ,Mentougou F~ jjJj~, Nansuletu j:ijffii'tIJ ~, Neimeng fJ ~, Sangonghe ~IiPJ, Shaanxi ~ i1!i ,Shanxi LlJi1!i, Shuixigou 7.ki1!i~, Songling *~, Talimu ~Tanglong ~.J:ijt Tulufan lti:t=1', Wensu lffil1'§, Wuchang Ji\';§§, Wudanggou :n~~, Xiangshan ~LlJ, Xiangxi(Hsiangchi)1!i'l!i€,
Xiaomeigou 'H;\t~, Xinjiang ~!1lI, Xishan i1!iLlJ, Yangxia [l!I;lL Yanjiagou M*~, Yaopo It~, Yihe a;fIJ, Yingzi -gr, Yinshan ~LlJ, Yongdingzhuang 7k~J±, Yuetan Jjl'l, Zaoshang ;il!t
LlJ, Zhaowudameng IlB.Wo~M, Zhejiang lViiI, Zhungeer /iui;m.

*,

m*,

B*0) ~ "- '7*clltrWl:l1Mmft:fi -.:to) 8 (ac~O)JJ1!1JQ:t-> J: lf~ffifIi) : *.~~llf;l;, GmGht-:-?~'-C ac ~ ~ :(J "? t-: : Gleichenites ? sp. A, Phlebopteris sp. A, Dictyophylium0) 5Hllllf~;: -? \"kotakiense Kimura et Tsujii, Sphenopteris sp. H, Ptilophyllum shinadaniense Kimura et
Tsujii, P. sp. d. P. hsiangshanense Wu, P. sp. A, Pterophylium ? sp., Pseudoctenis
nipponica Kimura et Tsujii:t->J:lfNilssonia sp. B, it-:i1!i9oLlJ~;I;'G, Sphenopteris sp. G,
Otozamites sp. C :t-> J: If Pseudoctenis ? sp. ~JJ1!1JQac~ L t-:,B*o)~,,-'7elltrWl.~llf~,*.~ti1!i9oLlJ~K~~~h, .:thGo)~K~~~~~~.~¥eJ! ~h -C \, ,tJ: \", 1'1. c' t ~J:.~ - '7 :/ 7 :k~-C.1tt*9;o Gh -C \" ~ ~ "- '7 *clltrWl.~llf~;: -?l '-C8$*IBtJ:~W~:(J\,', .:thG~J:., *.~~:t-> J: u--:i1!i9oLlJ~o)f:ll.1', :/.r< l) 7~, 90*7 ~7~:t-> J: If,
j:ij3 - D 'Y/{~O) 5M~~;:~1iU~h~::' t~JljjGI.1'~;: Lt-:,*H~Jljj . :k{t!.!';r· ti:#IEJlUTrans. Proc. Palaeont. Soc. Japan, N.S., No. 151, pp. 523-542,10 Figs., October 31,1988

862. ADDITIONAL NOTE ON UPPER PERMIAN
RADIOLARIAN FAUNA FROM ITSUKAICm,
WESTERN PART OF TOKYO PREFECTURE,
CENTRAL JAPAN*
KATSUO SASHIDA
Institute of Geoscience, University of Tsukuba, Ibaraki, 305
and

KEIJI TONISHI
Gyosei Junior and Senior High School, Tokyo, 101

Abstract. Well-preserved upper Permian radiolarians were recovered abundantly from achert block embedded in the Unazawa Formation distributed in Kashiwara, Itsukaichi Town,
Tokyo Prefecture, central Japan. A part of this radiolarian fauna including the families
Entactiniidae, Palaeoactinomiidae, Palaeoscenidiidae and Phacodiscidae and the Superfamily
Latentifistulidea has already been described by the present authors. This study is an addition to
the continuing investigation of this fauna and several newly discriminated genera and species ofEntactiniidae, Tormentidae, Albaillellidae and Spumellaria Incertae sedis are described. Amongthem, two genera Uberinterna and Trip/anospongos and ten species are proposed as new toscience.
This paper also attempts to compare the present radiolarian fauna with that of the
Ultra-Tamba Belt of Southwest Japan and of the Delaware Basin of West Texas.

observations with the use of a scanning electron
microscope (Ormiston and Lane, 1976; Ormistonand Babcock, 1979; Won, 1983; Ishiga andImoto, 1980; Ishiga et at., 1982b; Cheng, 1986;
Gourmelon, 1987 and others). The upper
Permian bilaterally symmetrical Radiolaria has
been described by Takemura and Nakaseko(1981), Ishiga et at. (1982b), Ishiga and Miyamoto (1986), and Caridroit and De Wever (1986)
from Southwest Japan. Recently, an abundant
and well-preserved upper Permian polycystinefauna has been reported by De Wever andCaridroit (1984), Sashida and Tonishi (1985,
1986) and Caridroit and De Wever (1986).
However, radiolarian faunas comparable to thisJapanese Upper Permian fauna have not beenrecognized outside of Japan, except for the

Introduction and acknowledgments
The study of the upper Paleozoic Radiolaria
began with the classical works on the European
Tethyan regions by RUst (1892). Taxonomic
works of the upper Paleozoic Radiolaria wereresumed during the latter half of 1940's withinvestigation by Deflandre (e.g. 1946), and were
followed by Foreman (1959, 1963) and Holdsworth (e.g. 1966, 1969) based on specimens
separated from hard rocks by the hydrofloric orhydrochloric acid extraction method. Since thelatter half of 1970's, the character of upper
Paleozoic radiolarian fauna has been clarified invarious areas of the world based on detailed* Received March 25,1988; revised manuscript accepted
August 4,1988
523

Katsuo SASHIDA and Keiji TONISHI

524

Guadalupian Albaillellaria (Ormiston andBabcock, 1979) and Spumellaria (Nazarov andOrmiston, 1985) from the Delaware Basin ofWest Texas. In this article, a three-fold subdivision of the Permian System is applied becauseof the popularity of such a usage among Japanesebiostratigraphers.
This paper is the third report on the description of Upper Permian radiolarians from Itsukaichi and several new genera and species ofEntactiniidae and Spumellaria Incertae sedis as
well as new species of Tormentidae andAlbaillellidae are proposed from newly discriminated assemblages. The present authors also
attempt to compare the present fauna with thatof the Ultra-Tamba Belt of Japan and of theDelaware Basin of West Texas, U.S.A.

o

The present authors express their deep
appreciation to Professor Hisayoshi Igo of theInstitute of Geoscience, University of Tsukuba
for his advice and continuous encouragement
throughout the course of the present study andfor his critical reading of the manuscript.
Geologic setting
The present authors once assumed that a chert
block yielding a rich Upper Permian radiolarianfauna is intercalated as a lenticular body within ashale facies of the Unit B of the Chichibu System(Sashida and Tonishi, 1985). The senior author
recently restudied the geology of the Itsukaichiarea. The following is a brief summary of geology
in this area from the north to south (Fig. 1).

3km........._ _,--_~I~-

Figure 1. Index map of the fossil locality.
X: fossil locality, B.T.L.: Butsuzo Tectonic Line, I.-K.T.L.: ItsukaichiKawakami Tectonic Line.

862.

Upper Permian Radiolaria [rom ltsukaichi

1) Mitsuzawa Formation (Takashima and Koike,
1984)
The Mitsuzawa Formation is mainly composed of a Lower to Middle Jurassic phyllitic
shale including exotic blocks of chert and limestone. The total thickness of this formation ismore than 700 m.
2) Fukazawa Formation (Takashima and Koike,
1984)This formation consists mainly of a Middle
Jurassic black shale and sandstone containing
exotic blocks of chert and limestone. Its total
thickness amounts to 800 m.
3) Unazawa Formation (Fujimoto, 1939: Takashima and Koike, 1984)
The Unazawa Formation consists mainly ofchert, siliceous shale and sandstone, and a repetitive sequence of these lithologies by tectonic
deformations is characteristic of this formation.
A sequence consisting of chert, siliceous shaleand sandstone, in ascending order, repeats six
times in this formation. The senior author
tentatively named these six sequences, Unit I to
Unit VI, beginning with the northernmost one. A
sandstone bed in the upper part of Unit IVintercalates a volcaniclastic layer containing limestone and chert blocks. The total thickness of theformation exceeds 2000m.
4) Hikawa Formation (Fujimoto, 1939; Takashima and Koike, 1984)
This Upper Jurassic formation is characterized
by the lower massive sandstone and the upper
pebbly shale containing exotic blocks of chert
and limestone. The total thickness of the formation is about 600m.
5) Gozenyama Formation (FUjimoto and Suzuki,
1957; Takashima and Koike, 1984)
The Gozenyama Formation is Early Cretaceous in age and is composed of a phyllitic
shale containing blocks of chert, limestone andvolcaniclastic rocks of various sizes. This formation attains the total thickness of l300m.
6) Ozawa Formation (Takashima and Koike,
1984)This Lower Cretaceous formation is composedof a phyllitic shale including small-sized sandstone blocks. The total thickness of this forma-

525tion exceeds 400 m.
The six formations trend in a NW-SE direction
and dip steeply northward. They are in contact
with each other by northward-dipping, highangled reverse faults.
The chert block containing the Upper Permian
radiolarians described in this paper is intercalated
within a volcaniclastic layer of Unit IV of the
Unazawa Formation (Fig. 1). This volcaniclastic
layer was formerly named the "Shiromaru
Paleozoic Formation", because it contains limestone blocks yielding Carboniferous to Permian
fusulinids.
Sample and age
The chert block which bears Upper Permian
radiolarians has a maximum diameter of about
10 m, and exhibits a synfold with a northwestplunging axis at an angle of 45 degrees (Sashida
and Tonishi, 1985, Fig. 2). This chert block
comprises 130 individual layers of chert, each ofwhich is separated by a thin film of mudstone
and these layers are altogether about 5 m thick:
The present authors sampled every layers in thischert block. Of these rock samples A-4, -7, -8 and-12 contain abundant and well-preserved radiolarian specimens. In particular, those specimensfrom samples A-4 and A-7 are treated in thispaper.
Samples A-4 and A-7 yield albaillellids suchas Follicucullus scholasticus Ormiston andBabcock morpho type II Ishiga and Miyamoto, F.
ventricosus Ormiston and Babcock, Albaillella
levis Ishiga, Kito and Imoto, Neoalbaillellaornitho[ormis Takemura and Nakaseko, and N
grypus Ishiga, Kito and Imoto. The specificcompositions of this albaillellid fauna ischaracteristic of the Neoalbaillella ornitho[omlis
Assemblage-Zone which is the uppermost radiolarian zone in the Permian System of Southwest
Japan (Ishiga, 1986b). Ishiga (1986b) estimatedthe geologic age of this assemblage zone to belate Late Permian.

526

Katsuo SASHIDA and Keiji TONISHI

Comparison of the Upper Permian radiolarianfauna of Itsukaichi with both the faunas of the
Ultra-Tamba Belt of Southwest Japan and the
Delware Basin of North America

In the Upper Permian radiolarian assemblagesof Japan, two distinct groups are recognizedbased upon the specific composition and thelithofacies in which radiolarians are preserved.
One assemblage is characterized by an associationof albaillellids including Follicucullus scholasticus, F ventricosus and some representative
species of Neoalbeillella (e.g., N. optima, N.
gracilis, and N. ornithoformis). This assemblage ischaracterized by the entire absence of F bipartitus Caridroit and De Wever, F hamatus Caridroit
and De Wever, F falx Caridroit and De Weverand F orthogonus Caridroit and De Wever. In
the Ultra-Tamba Belt, this assemblage occurs in aclastic rock facies (Musashino et al., 1987),
whereas it is usually recovered from a bedded
chert facies of both the Mino-Tamba Belt and the
Chichibu Belt of Southwest Japan. The otherassemblage is dominated by the presence ofFollicucullus hamatus, F bipartitus, F charveti,
F falx, F orthogonus and by the absence ofspecies of the genus Neoalbaillella. This assemblage is confirmed in clastic rocks or finely
alternating beds of siliceous shale and black shalefrom the Kamigori and Tatsuno Formations of
the Ultra-Tamba Belt (Caridroit and De Wever,
1984, 1986) and in similar lithologies in the
Kurosegawa Belt of the outer zone of Southwest
Japan (Ishiga and Miyamoto, 1986; Yamakita,1986). Ishiga and Miyamoto (1986) named thelatter Follicucullus bipartitus- F charveti assemblage, and they considered that this assemblage iscoeval with the radiolarian assemblage of theupper part of the Follicucullus scholasticus
Assemblage Zone in the chert facies of Southwest Japan. However, the variety of species of
the upper Permian radiolarian faunas from thechert facies is quite small except for thealbaillellid. On the other hand, a rich radiolarianfauna composed of Entactiniidae, Latentifistulidea and Albaillellidae is reported fromupper Permian clastic rocks of the Ultra-Tamba

Belt (De Wever and Caridroit, 1984; Caridroit
and De Wever, 1986). These authors describedmany species of Follicucullus, such as F bipartitus, F charveti, F falx, F orthogonus, F
hamatus, F. hamatus uncinatus, and F scholasticus. Among them, F scholasticus is the only
species in common between the faunas of Itsukaichi and Ultra-Tamba Belt. Also, they erected a few
new families Deflandrellidae and Ormistonellidae
in the Superfamily Latentifistulidea, and several
new genera and species were introduced in
Latentifistulidae. In these stauraxon polycystines, Ishigaum trifustis De Wever andCaridroit, Nazarovella gracilis De Wever andCaridroit and Pseudotormentus kamigoriensis De
Wever and Caridroit occur in both of the faunas.
At the generic level, Deflandrella and Latentifistula are also in common between the two
faunas. As already described by the present
authors, the fauna of Itsukaichi contains rich andvaried genera and species in the Family Entactiniidae. On the other hand, only four entactiniid
species, such as Hapientactinia ? ichikawai
Caridroit and De Wever, Entactinia ? sp., Entactinosphaera aubouini Caridroit and De Wever andE. echinata ? (Hinde) were described from the
Ultra-Tamba Belt. However, there are no speciesof entactiniid in common between the two
faunas. Caridroit and De Wever (1986) considered that the difference in the specific composition between those Upper Permian radiolarian faunas characterized by Neoalbaillella andthose comprising varied species of Follicucullus
resulted from the difference in lithofacies, diagenetic process, paleoenvironment and paleogeography. Ishiga (1986a) also stated that theradiolarian species of the Follicucullus bipartitusF charveti assemblage might have inhabited theocean near the land because they are usuallyfound in clastic rocks. Further investigations arenecessary to confirm this problem by accumulating detailed field and faunal data.
Ormiston and Babcock (1979) were the firstto describe two species of Follicucullus from thePermian Lamar Limestone of West Texas, North
America. Later, Nazarov and Ormiston (1985)
introduced rich Spumellarians from the Lamar

862.

Upper Permian Radiolaria from ltsukaichiand Heglar Limestones of the Bell Canyon
Formation of the Delaware Mountain Group.
Nazarov and Ormiston (1985) discriminated five
radiolarian units in the Permian of the Delaware
Basin. Among them, the Guadalupian faunal unit
is represented by the lower Hegleria mammifera
and the upper Follicucullus ventricosus Units.
The Follicucullus ventricosus unit is characterized by an association of such species as
Entactinosphaera cimelia Nazarov and Ormiston,
Entactinia tyrrelli Nazarov and Ormiston,
En tactinia parapycnoclada Nazarov and Ormiston,Hegleria mammifera Nazarov and Ormiston,Ruzhencevispongus girtyi Nazarov and Ormiston,
Copicyntroides asteriformis Nazarov and Ormiston, Latentifistula densa Nazarov and Ormiston,
Raphidociclicus gemellus americanus Nazarov
and Ormiston, Octatormentum babcockae
Nazarov and Ormiston, Tetragregnon scalpratus
Nazarov and Ormiston, Copiellintra sp., Follicucullus ventricosus Ormiston and Babcock, Fscholasticus Ormiston and Babcock and
Copicyntra sp. Among them, F ventricosus andF scholasticus are the species in common
between the two faunas.
As stated earlier, our knowledge of the Upper
Permian radiolarian taxonomy and Permian
radiolarian biostratigraphy outside of Japan isquite insufficient, and we are now in the processof accumulating more data from North America,
Europe, Russia, China and other areas. These
data are hoped to solve the problems of paleobiogeography of radiolarians, inter-regional correlation of various radiolarian zones and depositional environments of radiolaria-bearing rocks.
Systematic description
In the following description, the morphological terminology for those species belonging to
the Family Entactiniidae and the Superfamily
Latentifistulidea, basically follows that of Nazarov and Ormiston (1985) and that of Neoalbaillella is adopted from Takemura and Nakaseko (1981) and Ishiga et al. (1982b). All the
specimens described herein deposited in thecollection of Institute of Geoscience, Universityof Tsukuba (IGUT).

527

Order Polycystina Ehrenberg, 1838,
emend. Riedel, 1967
Suborder Albaillellaria Deflandre, 1953,
emend. Holdsworth, 1969
Family Albaillellidae Deflandre, 1952
Genus Neoalbaillella Takemura andNakaseko,1981
Type species: Neoalbaillella ornithoformis
Takemura and Nakaseko, 1981, Upper Permian:
Tamba Belt, Southwest Japan.
Neoalbaillella pseudogrypus Sashida andTonishi, n. sp.
figures 9-1-6.
Neoalbaillella grypus Takemura and Nakaseko; Sashida
and Tonishi, 1985, pI. 7, fig. 2.

Diagnosis: Neoalbaillella of bilaterally symmetrical shell with strongly curved apicalcone and cylindrical pseudoabdomen having 3 to
4 horizontal rows of large square to rectangular
windows.
Description: Apical cone imperforate, curves
strongly to ventral side. Its apex sometimes
curves downward. Pseudo thorax and pseudoabdomen cylindrical, with 4 to 5 horizontal rowsof windows. Pseudothorax with dorsal andventral triangular blade-like wings. Pseudoabdomen with two rods, ventral and dorsal rods
extending vertically downward and having 2 or 3
short spines projecting outwardly. Pore frames ofshell wall arranged in 5 or more horizontal rows.
Traveculae circular and lying on inner surface ofshell wall. Each row of pore frames has 10 to 12
windows. Windows of upper 2 rows small,
elliptical and those of center rows square to
oblong. Pore frames of the upper first to fourthhorizontally extended and touched with ventral
wing. Usually, the second frame connected with
Y-rod. Other frames adjoin lamellar-blade ofventral wing and rather large pores locatedbetween them. Shape of these pores trapezoidal
at upper and middle parts. Lower edge of ventral
wing connected with the fifth frame, making
reverse trapezoidal pore. The fifth frame often

528

Katsuo SASHIDA and Keiji TONISHI

protrudes toward the same direction of V-rod.
Length of dorsal wing about two-thirds of ventral
wing. X-rod of dorsal wing extends nearly perpendicularly to dorsal rod. Lamellar-blade of
dorsal wing contacts dorsal rod and possesses I
or 2 windows of circular to sub circular or
triangular shape.
Remarks: This new species is similar to
Neoalbaillella grypus Ishiga, Kito and Imoto inhaving a strongly bended apical cone. However,this new species is distinguishable from the latterby having longer pseudo abdomen and many
windows of rectangular to oval shape. Moreover,this species has characteristic pores in the skirt ofits ventral wing. Neoalbaillella pseudogrypus, n.
sp. differs from other species of Neoalbaillella inits strongly curved apical cone.
Measurements (in pm): Length of shell body
including apical cone, 250-271; maximum diameter of shell, 95-100; length of V-rod at
ventral wing, 142-214; maximum width ofwindow, 25-36; maximum length of window,
25-29, based on 20 specimens.
Etymology: Combination of latin pseudo andspecies name grypus.
Type: Holotype, Fig. 9-1, sample, A-4, IGUTKS0234: Paratypes, Fig. 9-2, sample, A-4, IGUTKS0235; Fig. 9-3, sample, A-4, IGUT-KS0240;
Fig. 9-4, sample, A-7, IGUT-KS0236; Fig. 9-5,
sample, A-7, IGUT-KS0208~ Fig. 9-6, sample,
A-4,IGUT-KS0212.
Suborder Spumellaria Ehrenberg, 1875
Family Entactiniinae Riedel, 1967
Subfamily Entactiniidae Riedel, 1967,
emend. Nazarov, 1975
Tribus Entactiniini Nazarov, 1975
Genus Entactinosphaera Foreman, 1963
Type species: Entactinosphaera esostrogyla
Foreman, 1963, Upper Devonian, Huron Memberof the Ohio Shale, U.S.A.
Entactinosphaera pseudocimelia Sashida andTonishi, n. sp.

Figures 7-1-3, 6-8.
? Entactiniidae gen. et sp. indet. Yamakita, 1986, pI. 1,
fig. 17.

Diagnosis: Entactinosphaera with 2 threebladed major spines. Inner shell bearing rather
short spines.
Description: Outer shell spherical with two
maj or spines. Inner shell much smaller than outerone. Diameter of inner shell usually less than
one-third to one-fourth that of outer shell. Inner
shell with circular pores. Internal framework
within inner shell not distinct in available
material. Inner and outer shell united by a pair ofmassive, three-bladed cross-beams which thicken
gradually away from inner shell and join withtwo major external spines. Numerous, thin,rod-like spines arising from inner shell. Some
specimens (e.g. Fig. 7-8) have very long spines
arising from inner shell, rarely contact with outershell like a pair of cross-beam (Fig. 7-7). Wall ofouter shell thin. Outer shell surface bears
numerous acute ridges or partitions intersecting
in disorganized manner to form polygonal cells.
These cells separate groups of pores in numbers
ranging from 1 to 4, most frequently with 2pores per cell. Inner surface of outer shellsmooth. Major spines usually three-bladed, rarely
four-bladed, just like a bundle of 3 thin rods
which gently tapers. Sometimes one of major
spines displays torsion of about 60 degrees.
Remarks: This new species resembles
Entactinosphaera cimelia Nazarov and Ormiston
described from the Guadalupian Lamar Limestone of West Texas in the feature of ridges orpartitions of the outer surface of the outer shell.
However, this new species can be distinguishedfrom the latter by having three-bladed major
spines shaped like a bundle of 3 thin and gently
tapering rods.
Measurements (in pm): Diameter of outershell, 140-175; diameter of inner shell, 38-44;
length of major spines, 71-143, based on 15
specimens.
Etymology: Combination of latin pseudo andspecies name cimelia.
Types: Holotype, Fig. 7-1, sample, A-4,
IGUT-KS0320: Paratypes, Fig. 7-2, sample, A-4,

862.

Upper Permian Radiolaria from Itsukaichi

IGUT-KS0235; Fig. 7-3, sample, A-7, IGUTKS0789; Fig. 7-6, sample, A-4, IGUT-KS3328;
Fig. 7-7, sample, A-4, IGUT-KS0150; Fig. 7-8,
sample, A-7, IGUT-KS0096.
Entactinosphaera brevispinosa Sashida andTonishi, n. sp.
figures 7-9 -13.

Diagnosis: Entactinosphaera having a rather
large outer shell with 0 to 6 short major spiI\es
and polygonal cells on outer surface of outershell.
Description: Outer shell spherical with fewer
than six major tluee-b1aded spines. Inner shellsmall, thin-walled, penetrated by predominantly
rounded pores. Diameter of inner shell less than
one-fourth the outer shell. Internal framework
within inner shell not distinct, but several verythin spicules present in available specimens.
Numerous, thin and rod-like spines arising frominner shell. Inner and outer shells united by apair of massive, tluee-bladed crossbeams withthicken rapidly away from inner shell and unit
with two major external spines. In some specimens, one of rod-like spines from inner shell
touches inner surface of outer shell. Wall of outershell thin. Shell surface bears numerous acuteridges or partitions intersecting in disorganizedmanner to form polygonal cells. These cells
surround groups of pores numbering from I to 5.
Short major spines three-bladed, and not twisted.
The number of spines variable. Length of major
spines less than half the diameter of outer shell.
Remarks: This new species is characterized byhaving a rather large spherical outer shell andvariable numbers of the short major spines. The
number of major spines is an important criterion
for the polycystine taxonomy. However, manykinds of radiolarian taxa which have inconsistent
numbers of major spines in the same species werereported from the Paleozoic rocks. For example,
Entactinosphaera crassiclatratus Nazarov andOrmiston from the Guadalupian Lamar Limestone has 2 to 6 major spines. In the present
collection, there are some specimens which either
have rudimentary major spines or lack the spine

529

entirely. In the latter case, these specimens havea tendency to develop an outer shell which bearcells surrounding only one pore. The present
authors tentatively included these specimens in
Entactinosphaera brevispinosa, n. sp. Those
specimens of this new species having 6 major
spines resemble Entactinosphaera ? crassispinosa
Sashida and Tonishi described from the samechert. However, the latter species has a smallerouter shell and thicker major spines than those of
the former.
Measurements (in ,um): Diameter of outershell, 280-330; diameter of inner shell, 45 -60;
length of major spine, 60-105, based on 12
specimens.
Etymology: Latin brevis meaning short andspinousus thorny or spino use.
Types: Holotype, Fig. 7-9, sample, A-4,
IGUT-KS0455: Paratypes, Fig. 7-10, sample,
A-4, IGUT-KS3347; Fig. 7-11 sample A-4
IGUT-KS3346; Fig. 7-12, sample, A-4, IGUT:
KS3316; Fig. 7-13, sample, A-4, IGUT-KS0432.
Entactinosphaera sp.
Figures 7-4,5.

Remarks: Several poorly preserved specimens
were obtained. This unnamed species is quite
similar to Entactinosphaeracimelia Nazarov andOrmiston in general shell shape. However, it
differs from the latter in having wider major
spines. Although this unidentified species somewhat resembles Entactinosphaera pseudocimelia,
n. sp., it is distinguishable from the latter in its
major spines having a triangular cross section.
Specific designation is rendered until more wellpreserved specimens are accumulated.
Measurements (in ,urn): Diameter of outershell, 110-140; diameter of inner shell, 30-38;
length of major spines, 170-220, based on fivespecimens.
Types: Illustrated specimens, Fig. 7-4, sample,
A-7, IGUT-KS0421; Fig. 7-5, sample, A-4, IGUTKS0753.

Tribus Triaenosphaeriniini Gourmelon, 1987
Type genus Triaenosphaera Deflandre, 1973

Katsuo SASHIDA and Keiji TONISHI

530

Genus Triaenoshpaera Deflandre, 1973 emend.
Gourmelon, 1987

Type species: Triaenosphaera sicarius Deflandre, 1973, Lower Carboniferous, Montagne
Noire, France.
Remarks: The genus Triaenosphaera wasoriginally introduced by Deflandre (1973) fromthe Lower Carboniferous of France. Subsequently, Holdsworth et al. (1978) examined
specimens of Triaenosphaera sicarius Deflandre
from an Upper Devonian chert of the Ford Lake
Shale of Alaska. They distinguished two morphotypes; Triaenosphaera sicarius Deflandre (s.s.)which has four major spines and T. sicarius (s.l.)having fewer than three major spines. Veryrecently, Gourmelon (1987) documented many
Tournaisian Radiolaria from Montagne Noire in
France. He erected up a new Tribe Triaenosphaeriniini in the Family Entactiniidae. The
genus Triaenosphaera is characterized by a single
spherical shell with four tetrahedrally arranged
spines. The four internal spicules have also atetrahedral disposition.
Triaenosphaera minutus Sashida andTonishi, n. sp.

somewhat similar in general shell feature to T.
described by Gourmelon(1987). However, the former species has larger
pores, fewer numbers of pores and shorter major
spines than those of the latter.
Measurements (in pm): Diameter of shell,
80-96; length of major spines, 60-75; diameterof pores, 7-11; number of pores on hemisphere;
28-31, based on 15 specimens.
Etymology: Latin minutus meaning small.
Types: Holotype, Fig. 8-1, sample, A-4,
IGUT-KS3489: Paratypes, Fig. 8-2, sample, A-4,
IGUT-KS3488; Fig. 8-3, sample, A-7, IGUTKS3478; Fig. 8-4, sample, A-4, IGUT-KS3490;
Fig. 8-5, sample, A-4, IGUT-KS0437; Fig. 8-6,
sample, A-4, IGUT-KS3497.

sicarius Deflandre

Subfamily Astroentactiniinae Nazarov
and Ormiston, 1985
Tribus Somphoentactiniini Kozur andMostler,1981
Genus Copicyntra Nazarov and Onniston,
1985

Type species: Copicyntra acilaxa Nazarov andOrmiston, 1985, Upper Carboniferous, southern
Ural, U.S.S.R.

Figures 8-1-6.

Diagnosis: Triaenosphaera with small sphericalshell and four radially arranged three-bladed
major spines.
Description: Small spherical shell with four
major spines. Cortical shell comprises small poreframes with poorly developed nodes at their
vertices. Hexagonal pore frames usually dominating. Thirty to 35 pores present on outersurface of hemisphere. Four major spines having
a tetrahedral disposition and comprise 3 narrow
longitudinal ridges alternating with 3 narrow
longitudinal grooves. Grooves and ridges almost
equal in width. Length of 4 major spines usuallyequal and four-fifths of diameter of shell andtheir distal end acute. Three-bladed thin internal
tetrahedral spicules continuous with major spines
at the inner surface of shell.
Remarks: Triaenosphaera minutus, n. sp. is

Copicyntra akikawaensis Sashida andTonishi, n. sp.
Figures 7-14-17.

Diagnosis: Copicyntra with 5 to 6 concentric
spheres and long conical spines.
Description: Spherical outer shell withnumerous long conical spines. Number of concentric sphere between outer shell and innermost porous sphere being usually 4 to 5. Inner
sphere small with many rounded pores. Radial
cross-beams arising from inner sphere and having
a three-bladed form. External spines connect
with radial cross-beam at base of outer shell.
External spines long and rod-like, acuminate indistal part. Length of external spine exceeds ahalf the diameter of outer shell. Three-bladed orthin rod-like pillars also combine superimposed

862.

Upper Permian Radiolaria from Itsukaichiconcentric spheres. External spines numberingfrom 17 to 20 on hemisphere. Outer spongy shell
represented by disorganized intervention of thinskeletal fibers forming small cells.
Remarks: Copicyntra akikawaensis, n. sp.,differs from the previously reported species of
Copicyntra in having fewer number of concentric
spheres and. rod-like external spines. This new
species somewhat resembles Copicyntra cuspidata Nazarov and Ormiston reported from thePermian Artinskian Stage, southern Ural ingeneral shell feature. However, the latter ·is
distinguished from the former by having threebladed external spines.
Measurements (in ,urn): Shell diameter,150-200; diameter of inner sphere, 36-45;
average diameter of intercalated shells proceeding
inward by from outer spongy layer, 160, 133,
113, 110 and 80; spine length, 40-93, based on
15 specimens.
Etymology: Species name akikawaensis isderived from Akikawa-river.
Types: Holotype, Fig. 7-14, sample, A-4,
IGUT-KS3345: Paratypes; Fig. 7-15, sample,
A-4, IGUT-KS0467; Fig. 7-16, sample, A-4,
IGUT-KS3332; Fig. 7-17, sample, A-7, IGUTKS3458.
Genus Uberinterna Sashida and Tonishi,
n. genus.
Type species: Uberinterna virgispinosum
Sashida and Tonishi, n. sp.
Diagnosis: Astroentactiniinae with thickspongy outer shell and porous inner shell. Inner
shell comprises 4 to 5, rarely more, thin concentric spheres. Internal spheres connected witheach other by numerous thin rod-like beams.
Internal spheres also being crossed by radial
cross-beams joining with base of major spines.
Remarks: This new genus is distinguishedfrom other genera of Astroentactiniinae, such as
Somphoentactinia Nazarov and Spongentactinella Nazarov by having concentric internal
spheres. On the other hand, the genera Copicyntra Nazarov and Ormiston and Copicyntroides Nazarov and Ormiston have superimposed

531

spine

/spongy outershellthin rod-likebeaml-1~·---R~~~<X1dinternal

inner

Figure 2. Schematic profile of Uberinterna
virgispinosum Sashida and Tonishi, n. g., n. sp.,presenting its nomenclature.

thin concentric spheres. The new genus Uberinterna is additionally characterized by threebladed cross-beams. These features of crossbeams are not recognized in the previously
reported genera of Astroentactiniinae.
Etymology: Latin uber meaning abundant andinterna, inner part; gender, neuter.
Uberinterna virgispinosum Sashida andTonishi, n. sp.
Figures 2; 8-7-12.

Diagnosis: Uberinterna with thick spongy
outer shell and 4 to 5 thin concentric sphericalshells. Several maj or spines rod-like and rather
short.
Description: Spherical outer shell, thick andspongy with several rod-like spines. Outer surfaceof outer shell uneven lacking any small spines,
whereas inner surface usually smooth (Figs. 8-9,
12). However, some specimens have spongy
fabric and intervening fibers, which are incontact with outer surface of inner shell. Thickness of outer shell wall exceeds one-fifth the oneof a half diameter of outer shell. Major spines
rather short and conical or rod-like. They
gradually taper off to a distal end. Sometimes,
wide and rather deep grooves develop from baseto one-third the length of major spines. Six major
spines counted in well-preserved specimens. Inner
shell comprises 4 to 5 thin concentric spheres.

532

Katsuo SASHIDA and Keiji TONISHI

Innermost sphere has a thin wall penetrated byrounded oval pores. Several thin internal spicules
observed in innermost sphere, but their disposition not clear in presently available specimens.
Three to 4 concentric spheres small with roundedpores. Each concentric sphere being connectedby thin rod-like beams. Rarely very small
secondary spines or nodes developing on outersurface of outermost sphere of inner shell.
Diameter of inner shell less than a half diameterof outer shell. Six radial cross-beams arising frominner shell have a three-bladed form. They
become gradually wide toward inner surface ofouter shell and contact with external spines.
Remarks: This new species somewhat resembles Thecentactinia riedeli (Foreman) in
general shell shape. However, the former is easily
distinguished from the latter by the above
described shell characters.
Measurements (in ,urn): Diameter of outershell, 250-300; thickness of spongy layer ofouter shell, 25-30; length of external spines,
65-100; diameter of outermost sphere of innershell, 85-93; diameter of innermost sphere,
25 -33; average diameter of intercalated spheresproceeding inwardly from the outermost sphereof inner shell, 80, 47 and 33, based on 11
specimens.
Etymology: Latin virga, twig or branch andspinosus, thorny.
Types: Holotype, Fig. 8-7, sample, A-4,
IGUT-KS3496: Paratypes, Fig. 8-8, sample, A-4,
IGUT-KS3453; Fig. 8-9, 12, sample, A-4, IGUTKS3492; Fig. 8-10, sample, A-7, IGUT-KS0301;
Fig. 8-11, sample, A-4, IGUT-KS3487.
Superfamily Latentifistulidea Nazarov andOrmiston, 1983
Family Tormentidae Nazarov andOrmiston, 1983
Genus Tetratormentum Nazarov andOrmiston, 1985
Type species: Tetratormentum narthecium
Nazarov and Ormiston, Upper Carboniferous,
Gzhelian Stage, southern Ural, U.S.S.R

spine

ventral)"/~internal sphere-

Figure 3. Schematic view of Tetratormentum
acutum Sashida and Tonishi, n. sp. presenting its
nomenclature.

Tetratormentum acutum Sashida and Tonishi,
n. sp.
Figures 3; 10-7, 10

Diagnosis: Tetratormentum with distorted
pyramidal shell. One small spherical internal
sphere with very thin four-rayed internal framework enclosed in rather thick spongy shell (Fig.
3).
Description: Outer spongy pyramidal shell
thick, rather large and distorted toward dorsal
side. Spongy fabric of outer shell very fine. Distal
end of spongy shell abruptly tapers towardterminal spine. Internal framework represented
by a nonporous sphere somewhat shifted towardbase. Three very thin rays arising from sphere atan angle of about 120 degrees from one anotherand fourth one bended toward dorsal side at anangle of about 30 degrees from a vertex (Fig.
10-10). Diameter of internal sphere less than
one-fourth the length of internal ray. Internal ray
gradually thicken toward distal part and connected with external spine at base of spongyshell. Terminal spines fairly thick and conical.
Some forms possessing 2 or 3 short and shallow
openings near base. Length of well-preserved
terminal spine about one-third of internal ray.
Remarks: Tetratormentum acutum, n. sp. ischaracterized by its distorted spongy shell withfairly massive and conical terminal spines. This
new species somewhat resembles Tetrator-

862.

Upper Permian Radiolaria from 1tsukaichi

mentum narthecium Nazarov and orrrriston , thetype species of the genus Tetratormentum, However, the latter species has a more roundedpyrarrridal shell and thinner terrrrinal spines than
the former.
Measurements (in ,urn): Height of pyrarrrid
except terrrrinal spine, 255-255; basal width,280-330; diameter of internal sphere, 35 -45;
diameter of internal rays, 4-8; length of terrrrinal
spines, 7 -1 0, based on 9 specimens.
Etymology: Latin acutus meaning acute or
sharpened.
Types: Holotype: Fig. 10-10, sample, A-4,
IGUT-KS0948: Paratype, Fig. 10-7, sample, A-4,
IGUT-KS0945.
Tetratormentum globiforme Sashida andTonishi, n. sp.
Figures 4; 10-11,12.

Diagnosis: Tetratormentum with globular
coarse spongy shell and porous internal sphere.
External terrrrinal spines thick and long conicalarising from internal rays (Fig. 4).
Description: Globular shell thick with aporous internal sphere and conical massive external spines which arise from internal rays. Spongyshell comprising fairly coarse spongy fabric,
sometime~ creating an impression of it being~xternal

533

divided into several layers. Inner surface of shell
usually smooth, but sometimes coarse spongy
fabric of shell combined with internal sphere.
Porous internal sphere spherical to depressed
spherical with circular to oval pores. Diameter ofinternal sphere less than one-third of the outer shell
diameter. Internal rays arising from internal
sphere at an angle of 120 degrees from one
another and the fourth ones arranged perpendicularly to other three. Usually, internal rays
rod-like, but sometimes three-bladed. Thickterrrrinal spines also rod-like and gradually taper
off distally.
Remarks: In some specimens, there observed
are one or two incomplete spheres made of acoarse spongy fabric in which the internal sphereis closed. The present authors tentatively included these forms to this species.
Measurements (in flm): Diameter of shell,
300-350; diameter of internal sphere, 70-90;
maximum diameter of terrrrinal spines, 35-50;
length of the terrrrinal spines 120-180, based on
8 specimens.
Etymology: Latin globus meaning ball andformis, shaped.
Types: Holotype, Fig. 10-11, sample, A-4,
IGUT-KS0923: Paratype, Fig. 10-12, sample,
A-4, IGUT-KS0946.
Genus Octatormentum Nazarov andOrrrriston, 1985

spine

~n

~I

\,!
sphereTypespecies:
Octatormentum cornelli
Nazarov and Orrrriston, 1985: Lower Perrrrian,
Leonardian Stage, Bone Spring Limestone, West
Texas, U.S.A.
Octatormentum ? floriferum Sashida andTonishi, n. sp.

spongy/Figures 5; 10-1-4.

fabric /ray

Figure 4. Schematic view of Tetratormentum
globiforme Sashida and Tonishi, n. sp. presenting its
nomenclature.

Diagnosis: Tormentidae with spongy shell andinternal sphere. Spongy shell of double pyramidal form with six major spines, four emerging atapices of each pyrarrrid. External spines continuous with 6 internal rays (Fig. 5).
Description: Rather large shell of double

534

Katsuo SASHIDA and Keiji TONISHI,,~erminal

spine

spine

spongyshellinternalA

ray

Figure 5. Schematic view of Octatormentum ?
floriferum Sashida and Tonishi, n. sp. presenting its
nomenclature.

pyramidal form whose distal half of apices
protruded in a dome-like fashion. Terminal
spines emerging at 4 equatorial corners and 2
apices. Diameter of dome-like protrusion lessthan height of shell. Shell thick and spongy.
Inner surface of shell smooth, but rarely finespongy fabrics sticking out. Internal sphere small,
nonporous and covered with 6 emerging rays.
Junction of these rays not observable within thesphere. Diameter of internal sphere less than
one-fifth that of outer shell. Internal spheresituated at the center of shell. Internal rays thin,rod-like and continuous to base of major external
spines. External spines rod-like, finely threebladed at the basal part, and gradually tapering
off distally. Six external spines usually equal
length. Maximum length of external spines nearly
equal with diameter of dome-like protrusion.
Remarks: According to Nazarov and Ormiston(1985), the genus Oetatormentum is characterized diagnostically by having 3 shells
and 6 major spines. Although the present

B

Figure 6. Schematic view of Tripianospongos
musashiensis Sashida and Tonishi, n. g., n. sp. presenting
its nomenclature.
A: External view, B: Two times enlarged cross section
along the profile a-a'.

authors' specimens have only 2 shells, other shellfeatures are quite identical with the criteria given
by Nazarov and Ormiston (1985). Therefore, thepresent authors tentatively assign this new
species to the genus Oetatormentum. Oetatormentum ? floriferum, n. sp. is easily distinguished from other previously described
species of Oetatormentum by the abovementioned shell characters.
Measurements (in pm): Maximum height ofshell excluding terminal spine, 290-320; maximum diameter of shell, 300-350; diameter ofinternal sphere, 30-45; length of external terminal spines, 45-55, based on 8 specimens.
Etymology: Latin florifer meaning flower
bearing.
Types: Holotype: Fig. 10-2, sample, A-4,

4
Figure 7. 1-3,6-8: Entactinosphaera pseudocimelia Sashida and Tonishi, n. sp. 1, holotype, x 150,
sample A-4, IGUT-KS0320; 2, paratype, x 200, sample A-4, IGUT-KS0235; 3, paratype, x 150, sample A-7,
IGUT-KS0789; 6, paratype, x 150, sample A-4, IGUT-KS3328; 7, paratype, x 200, sample A-4, IGUT-KS0150;
8, paratype, x 200, sample A-7, IGUT-KS0096. 4,5: Entactinosphaera sp. 4, x 200, sample, A-7 IGUT-KS0421; 5,
x 100, sample, A-4 IGUT-KS0753. 9-13: Entactinosphaera brevispinosa Sashida and Tonishi, n. sp. 9, holotype,x 100, sample A-4, IGUT-KS0455; 10, paratype, x 100, sample A-4, IGUT-KS3347; 11, paratype, x 100, sample
A-4, IGUT-KS3346; 12, paratype, x 100, sample A-4, IGUT-KS33l6; 13, paratype, x 100, sample A-4,
IGUT-KS0432. 14-17: Copicyntra akikawaensis Sashida and Tonishi, n. sp. 14, holotype, x 225, sample A-4,
IGUT-KS3345; 15, paratype, x 150, sample A-4, IGUT-KS0467; 16, paratype, x 150, sample A-4,
IGUT-KS3332; 17, paratype, x 150, sample A-7, IGUT-KS3458.

862.

Upper Permian Radiolaria from Itsukaichi

535

Katsuo SASHIDA and Keiji TONISHI

536

IGUT-KS3454: Paratypes, Fig. 10-1, sample,
A-4, IGUT-KS3452; Fig. 10-3, sample, A-4,
IGUT-KS3471; Fig. 10-4, sample, A-4, IGUTKS3472.
Octatormentum ? sp.
figures 10-5,6,8,9.

Description: Three-sided, rather large and thinspongy bipyramidal shell enclosing six-rayed internal framework. Dome-like protrusions present
at each corner. Small modes also developing at
the top of dome-like protrusion and being
continuous with 6 internal rays. Internal rays
rather thick and rod-like. Internal sphere notobserved amongst presently available material.
Remarks: Several poorly preserved specimens
were obtained. This unidentified species
characteristically has three-sided bipyramidalshell. The poor state of preservation prevents
observation of the internal sphere. Somecharacters of this unidentified species differ fromthe criteria of the genus Octatormentum. Because, this species has a bipyramidal shell with
six internal rays, the present authors questionably assigned this unidentified species to thegenus Octatormentum. Both the generic andspecific designations of this taxon are waived
until well-preserved specimens become available.
Measurements (in ,urn): Maximum height ofouter shell, 270-285; maximum diameter ofouter shell, 260-280, based on 5 specimens.
Types: Illustrated specimens: Fig. 10-5,6,
sample, A-4, IGUT-KS0820; Fig. 10-8,9, sample,
A-4, IGUT-KS0923.

Spumellaria incertae sedis
Genus Triplanospongos Sashida and Tonishi ,n. genus.

Type species: Triplanospongos musashiensis
Sashida and Tonishi, n. sp.
Diagnosis: Shell comprising three doubleridged arms with triangular spongy fabrics andconical terminal spines. Arms radiating from thecenter of shell at an angle of 120 degrees. Smalltriradiate plate pr.esent at the center of shell. One
or two narrow ridges, I-shaped in cross section,
being arranged parallel to arm at nearly mid-partof spongy shell. This ridge coming in contact
with arm at distal end of shell or amalugamatedwith surrounding spongy fabrics.
Remarks: Triplanospongos, n. g. is quite
similar to the genus Foremanhelena De Weverand Caridroit of the Family Tormentidae inouter shell shape. However, the shell structure of
the former genus is completely different fromthe latter. Namely, this new genus does not havethe tube-like triradiate arms and spherical central
shell. This character is not recognized in othergenera of the Superfamily Latentifistulidea.
Therefore, the present authors place this new
genus in the Spumellaria incertae sedis. The
genus Tetraditryma Baumgartner of the Mesozoic
Family Hagiastridae possess basically H-shaped
external beams. Nevertheless, the ray of thegenus Tetraditryma is composed of a medullaryshell, cortical bar, cortical walls and pores(Baumgartner, 1980, fig. 4).
Etymology: Latin tri meaning three, plano to
make flat, and pongos sponge; gender masculine.
Triplanospongos musashiensis Sashida andTonishi, n. sp.
figures 6; 9-7 -12.

? Paronaella sp. A, Wakita, 1983, pI. 7, fig. 7.
Angulobracchia? sp., Yoshida and Murata, 1985, pI. 2,
fig. 18.

~ Figure 8.
1-6: Triaenosphaera minutus Sashida and Tonishi, n. sp. 1, holotype, x 350, sample A-4,
IGUT-KS3489; 2, paratype, x 350, sample A-4, IGUT-KS3488; 3, paratype, x 350, sample A-7, IGUT-KS3478;
4, paratype, x 350, sample A-4, IGUT-KS3490; 5, paratype, x 350, sample A-4, IGUT-KS0437; 6 para type x
350, sample A-4, IGUT-KS3497.
',
7-12: Uberinterna virgispinosum Sashida and Tonishi, n. sp. 7, holotype,x 100, sample A-4,
IGUT-KS3496; 8, paratype, x ISO, sample A-4, IGUT-KS0301; 9, paratype, x 100, sample A-4, IGUT-KS3492;
10, paratype, x 150, sample A-7, IGUT-KS0301; 11, paratype, x 150, sample A-4, IGUT-KS3487; 12, x 350,
enlargement of the internal shell of Fig. 8-9.

862.

Upper Permian Radiolaria jinm Itsukaichi

537

538

Katsuo SASHIDA and Keiji TONISHI

862.

Upper Permian Radiolaria from Itsukaichi

Diagnosis: Triangular platy shell comprising
three arms and covered by spongy fabrics. Eacharm of triangular spongy shell tipped by a rather
long, conical, terminal spine.
Description': Triangular platy shell comprising
three double-ridged arms and covered by spongy
fabrics. Arms diverging at an angle of 120 degrees
from center. Triradiate and rather massive small
plate located at center of shell. One of two ridges
fabricating double-ridged arm usually disappearing at the distal end. In rare instances,both ridges becoming amalgamated with eachother to form single-ridged arm. At distal part ofshell, arm merging with spongy fabric. One or
two massive I-shaped ridge running parallel toarm in the middle part of spongy shell and theridge often coming to merge with one of ridges
on the arm. Spongy fabrics serving to connect
arm and I-shaped ridge in such manner as shownin Fig. 6. Pores of spongy fabric rather large andcircular to ovaL Spongy fabrics usually covering
I-shaped ridges at the distal part of shell. A rather
long conical spine terminating from one of ridges
on the arm at distal end. Three narrow andshallow grooves present near the base of spines.
Length of spines about one-third the distancefrom center to distal end of arm. Three side oftriangular spongy shell slightly indented near
mid-point as marked a or a' in Fig. 6. Thicknessof double-ridged arm being nearly one-third oflength of arm.
Remarks: As discussed earlier, Triplanaspongos musashiensis, n. sp. resembles Foremanhelena triangula De Wever and Caridroit. Furthermore, this new species is similar to Tormentum
circumfusum Nazarov and Ormiston describedfrom the Lower Permian of southern Ural in its
outer shell shape. However, this new species iseasily distinguished from these two species by*- Figure 9.

539

lacking the important character of stauraxon
polycystines.
Measurements (in ,urn): Length of rays from
center to distal end of shell, 170-230; height oftriangle, 340-400; thickness of shell, 65-72;
length of terminal spines 45-90, based on 25
specimens.
Etymology:
Species name musashiensis
comes from the ancient geographical name,Musashi, for the western part of Tokyo Prefecture.
Types: Holotype, Fig. 9-7, sample, A-4,
IGUT-KS0371: Paratype, Fig. 9-8, sample, A-4,
IGUT-KS0372; Figs. 9-9,12, sample, A-7, IGUTKS0766; Fig. 9-10, sample, A-4, IGUT-KS0370;
Fig. 9-11, sample, A-4, IGUT-KS0826.
References
Baumgartner, P. O. (1980): Late Jurassic Hagiastridae
and Patulibracchidae (Radiolaria) from the Argolis
Peninsula (Peloponnesus, Greece). Micropaleontology. vol. 26, no. 3, pp. 274-322, pis. 1-12.
Caridroit, M. and De Wever, P. (1984): Description dequelques nouvelles especes de Follicucullidae etd'Entactiniidae (Radiolaires Polycystines) du
Permien du Japon. Geobios, vol. 17, no. 5, pp.
639-644, pis. l.
-and (1986): Some Late Permian radiolarians
from pelitic rocks of the Tatsuno Formation(Hyogo Prefecture), southwest Japan. Marine
Micropaleontology, vol. 11, nos. 1-3, pp. 55-90,
pis. 1-5.
Cheng, Y. N. (1986): Upper Paleozoic (Upper Devonian
and Carboniferous) Radiolaria from the Ouachita
Mountains, Oklahoma and Arkansas. National
Museum of Natural Science, Special Pub., no. 1,
pp. 1-310, pis. 1-4l.
Deflandre, G. (1946): Radiolaires et Hystrichosphaerides du Carbonifere de la Montagne Noire.
C.R. A cad. Sci, Paris, vol. 223, D, pp. 515-517.
(1973): Observations et remarques sur les Radiolaires Sphaerellaires du Paleozoique, a propos dune
nouvelle espece viseenne, du genre Forernaniella

1-6: Neoalbaillella pseudogrypus Sashida and Tonishi, n. sp_ 1, holotype, x 150, sample A-4,
IGUT-KS0234; 2, paratype, x 150, sample A-4, IGUT-KS0235; 3, paratype, x 150, sample A-4, IGUT-KS0240;
4, paratype, x 150, sample A-7, IGUT -KS0236; 5, paratype, x 150, sample A-7, IGUT-KS0208; 6, para type, x 150,
sample A-4, IGUT-KS0212.
7-12: Triplanospongos musashiensis Sashida and Tonishi, n. sp. 7, holotype, x 100, sample A-4,
IGUT-KS0371; 8, paratype, x 150, sample A-4, IGUT-KS0372; 9, paratype, x 175, sample A-7, IGUT-KS0766;
10, paratype, x 150, sample A-4, IGUT-KS0370; 11, paratype, x 150, sample A-4; IGUT-KS0826; 12, x 350,
enlargement of the central part of shell and triradiate plate.

540

Katsuo SASHIDA and Keiji TONISH/

862.

Upper Permian Radiolaria from Itsukaichi

Defl., parfait intermediaire entre les periaxoplastidies et les Pylentonemides. Ibid., vol. 276, D,
pp. 1147-1151, pIs. 1-2.
De Wever, P. and Caridroit, M. (1984): Description dequelques nouveaux Latentifistulidea (Radiolaires
polycystines) paleozoiques du Japan. Rev. Micro·
paleontol., vol. 27, no. 2, pp. 98-106, pIs. 1-2.
Foreman, H. P. (1959): A new occurrence of Devonian
Radiolaria in calcareous concretions of the Huron
Member of the Ohio Shale. Jour. Paleont., vol. 33,
no. 1, pp. 76-80, pI. 1.
- - , (1963): Upper Devonian Radiolaria from the
Huron Member of the Ohio Shale. Micropaleonto·
logy, vol. 9, no. 3, pp. 267-304, pIs. 1-9.
Fujimoto, H. (1939): On the Torinosu Series of the
Kwanto Mountainland (JE). Prof H. Yabe Mem
Vol., pp. 457-479.
- - and Suzuki, M. (1957): On the geology of Ogouchi
district (1). Rep., Cultural Properties Surv., Tokyo
Metropolis, vol. 3, pp. 1-28.
Gourmelon, F. (1987): Les Radiolaires Tournaisiens desnodules phosphates de la Montagne Noire et desPyrenees centrales. Biostratigraphie du Paleozoique. vol. 6, pp. 1-172, pIs. 1-22.
Holdsworth, B. K. (1966): Radiolaria from the
Namurian of Derbyshire. Palaeontology, vol. 9, pt.
2, pp. 319-329, pI. 54.
- - (1969): The relationship between the genus
Albaillella Deflandre and the ceratoikscid Radiolaria. Micropaleontology, vol. 15, no. 2, pp.
230-236, pI. 1.
Jones, D. L. and Allison, C. (1978): Upper
Devonian radiolarians separated from chert of theFord Lake Shale, Alsaka. Jour. Res. U.S. Geol.
Survey, vol. 6, no. 6, pp. 775 -788.
ishiga, H. (1986a): Late Carboniferous-Permian radiolarian biostratigraphy in Japan with special reference to distribution and phyletic lineage of
Follicucullus in Late Permian time (JE). News ofOsaka Micropaleontologists, Special Vol. 7, pp.
1-8.
--(l986b): Late Carboniferous and Permian radiolarian biostratigraphy of Southwest Japan. Jour.
Geosci. Osaka City Univ., vol. 29, art. 3, pp.
89-100.
- - and lmoto, N. (1980): Some Permian radiolarians in541

the Tamba district, Southwest Japan. Earth
Science (Chikyu Kagaku), vol. 34, no. 6, pp.
333-345, pIs. 1-5.
- - , Kito, T. and lmoto, N. (1982): Late Permian
radiolarian assemblages in the Tamba district andan adjacent area, Southwest Japan. Ibid., vol. 36,
no. 1, pp. 10-22, pIs. 1-5.
--and Miyamoto, T. (1986): Follicucullus (Radiolaria) from the Upper Permian Kuma Formation,
Kyushu, Southwest Japan. Trans. Proc. Palaeont.
Soc. Japan, N. S., No. 141, pp. 322-335, pIs. 1-2.
Musashino, M., Kirimura, S. and ishiga, H. (1987):
Discovery of Neoalbaillella (Late Permian radiolaria) from the Oi Formation of Ultra-Tamba Zone,
Southwest Japan (1). Earth Science (Chikyu
Kagaku), vol. 41, no. 3, pp. 194-197.
Nazarov, B. B. and Ormiston, A. R. (1985): Radiolaria
from the late Paleozoic of the southern Urals,
USSR and West Texas, USA. Micropaleontology,
vol. 31, no. 1, pp. 1-54, pIs. 1-6.
Ormiston, A. R. and Babcock, L. (1979): Follicucullus,
new radiolarian genus from the Guadalupian(Permian) Lamar Limestone of the Delaware Basin.
Jour. Paleont., vol. 53, no. 2, pp. 328-334, pI. 1.
--and Lane, R. A. (1976): A unique radiolarianfauna from the Sycamore Limestone (Mississippian) and its biostratigraphic significance.
Palaeontogr., vol. 154, no. 4-6, pp. 158-180, pIs.
1-6.
RUst, D. (1892): Beitrage zur Kenntniss der fossilen
Radiolarien aus Geisteinen der Trias und derpalaeozoischen Schichten. Palaeontogr., vol. 38,
pp. 107-192, pIs. 6-30.
Sashida, K. and Tonishi, K. (1985): Permian radiolarians
from the Kanto Mountains, Central Japan - Some
Upper Permian Spumellaria from Itsukaichi,
western part of Tokyo Prefecture -. Sci Rep..
Inst. Geosci. Univ. Tsukuba, Sec. B, vol. 6, pp.
1-19, pIs. 1-7.
- - and - - (1986): Upper Permian stauraxon polycystine Radiolaria from itsukaichi, western part ofTokyo Prefecture. Ibid., vol. 7, pp. 1-13, pIs. 1-4.
Takashima, K. and Koike, T. (1984): Stratigraphy andgeological structure of Mesozoic strata in the
Gozenyama-Itsukaichi area, southeastern part of
the Kanto Mountains (JE). Sci Repts. Yokohama~ Figure 10. 1-4: Octatormentum ? floriferum Sashida and Tonishi, n. sp. 1, paratype, x 75, sample A-4,
lGUT- KS3452; 2, holotype, x 75, sample A-4, IGUT-KS3453; 3, paratype, x 75, sample A-4, IGUT-KS3471; 4,paratype, x 75, sample A-4, IGUT-KS3472.
5, 6, 8, 9: Octatormentum ? sp. 5,6, x 150, a stereo pair showing internal rays, sample A-4, IGUT-KS0820;
8 9 x 150 a stereo pair showing internal feature, sample A-4, IGUT-KS0923.
, '7,10: 'Tetratormentum acutum Sashida and Tonishi, n. sp. 7, paratype, x 100, sample A-4, IGUT-KS0945;
10, holotype, x 150, sample A-4, IGUT-KS0948.
11,12: Tetratormentum globiforme Sashida and Tonishi, n. sp. 11, holotype, x 100, sample A-4,
lGUT-KS0923; 12, paratype, x 100, sample A-4, lGUT-KS0946.

542

Katsuo SASHIDA and Keiji TONISHI

Nat. Univ., Sec. II, no. 31, pp. 29-50, pIs. 1-3.
Takemura, A. and Nakaseko, K. (1981): A new Permian
radiolarian genus from the Tamba Belt, Southwest
Japan. Trans. Proc. Palaeont. Soc. Japan, N. S.,
124, pp. 208-214, pIs. 33-34.
Wakita, K. (1983): Allocthonous blocks and submarine
slide deposits in the Jurassic formation southwestof Gujo-hachiman, Gifu Prefecture, central Japan(JE). Bull. Ceol. Surv. Japan, vol. 34, no. 7, pp.
329-342, pIs. 1-8.
Won, Moon-Zoo (1983): Radiolarian aus dem Unterkarbon des Rheinischen Schiefergebirges (Deutsch-land). Palaeontgr. Abt. A, vol. 182, pp. 116-175,
pIs. 1-14.
Yamakita, S. (1986): Discovery of Late Permian radiolarians including Follicucullus charveti from theKurosegawa terrain in eastern Shikoku (J). Jour.
Ceol. Soc. Japan, vol. 92, no. 12, pp. 909-911, pI.
l.

Yoshida, H. and Murata, M. (1985): Permian radiolarianbiostratigraphy from the northeastern part of Saiki
City, Oita Prefecture, Japan (JE). Jour. Ceol. Soc.
Japan, Vol. 91, no. 8, pp. 525-533, pIs. 1-2.
(JE): in Japanese with English abstract, (J): in Japanese.

Kashiwara ;fSIJ.i{, Itsukaichi Town E.BrtJlBJ, Akikawa tk)ll, Musashi JilCJil .

• *m~$,E.BrtJ~G.~~~$~4A*~ft~~~~.~:.*mE.BrtJlBJ~IJ.i{#~K~;fp~ ~i1alR~K::''i3"~ h~ 7- l' - I- ;fiJ;1i.iJ' Gltf*ffN.fftJ:~$~JVA*~ft~iijp:l:f;::'.~ ~o ::.
~~ft~i!J4'kJ~~ ? to, Entactiniidae, Palaeoactinomidae, Palaeoscenidiidae, Phacodiscidae fl-l:k.
If Latentifistulidea ~fl-~-$f;::'",:)\"-Clt~-C·f;::'~~Gf;::'J: IJ ilc~· .~~h -(\,'~o ;tlilf5e-c·
Ii Entactiniidae, Tormentidae, Albaillellidaef4l:k.lff9f ,&I,7f'~ ~ Spumellaria f;::'"':) \" -C ~t-: f-:.~iM~
rr\,', Uberinterna, Triplanospongos~ 2 ~,&I,~'i3"IJb, lO~~.~~~lffit~1j L, ilC~ Lt.:o ;tlilf5e-C·
tt~GKE.BrtJ.~$~4A*~ft~i!J4'kJ~~~mB;t~B.*~~$~4A*~ft~i!J4'kJ~l:k.
lf~t* West Texas ~ Delaware Basin ~~ft~i!J4'kJ~~ ~.1t~~rr-:,f.:o 1~B3MJ95· }!~;!(=

Trans. Proc. Palaeont. Soc. Japan, N.S., No. 151, pp. 543-563,9 Figs., October 31, 1988

863. SOME CHARACTERISTIC RADIOLARIANS FROM
LOWER JURASSIC BEDDED CHERTS OF THE
INUYAMA AREA, SOUTHWEST JAPAN*
RIE HORI
Department of Geosciences, Faculty of Science,
Osaka City ·University, Osaka 558

Abstract. Four radiolarian species, including two new species, of the family Syringacapsidae Foreman are described from the lowest Jurassic bedded cherts of the Inuyama area,
central Japan. These species belonging to the genera Katroma. Syringocapsa and Gigi are
representatives of the Parahsuum simp/um Assemblage, one of the important early Jurassic
radiolarian assemblages established in Southwest Japan. On the basis of morphology andbiostratigraphic distribution, both genera Gigi and Katroma are regarded as descendants of thegenus Syringocapsa.
The species of Katroma in the Lower Jurassic are biostratigraphic marker taxa because of
their short range and world-wide occurrences. Therefore, the upper part of the Parahsuum
simp/um Assemblage-zone with species of Katroma is probablY assignable to upper Sinemurian
to upper Pliensbachian.

Introduction

Jurassic radiolarians have followed to establish
detailed radiolarian zones. However, a number of
early Jurassic radiolarian species still remain
undescribed, because paleontological studies havenot been carried out to the fullset extent except
for those by Isozaki and Matsuda (1985), Kishida
and Hisada (1985), Yoshida (1986), Hori and
Yao (1988) and Sashida (1988). The purpose ofthis paper is to describe the earliest Jurassic
radiolarians of the genera Katroma, Gigi and
Syringocapsa, from the bedded cherts in the
Inuyama area (Mino Terrane), the Inner Zone ofSouthwest Japan. These species are significant inestablishing an Early Jurassic correlation ofradiolarian zones between Japan and other areasin the world, because 1) they are short ranged
and co-occur with well-known index species
reported from east-central Oregon, Queen
Charlotte Islands, British Columbia and Turkey,
and 2) they occur commonly from the Lower
Jurassic rocks through0ll_t Southwest Japan, withSince 1980, attention of radiolarian workersof the world has been focused on early Jurassic
radiolarians because of the lack of sufficient dataon their stratigraphic distribution, morphology
and phylogeny. Pessagno and his colleagues and
De Wever systematically described Early Jurassic
radiolarian species from North America, Turkey
and Greece (Pessagno and Blome, 1980; Pessagno
and Poisson, 1981; De Wever, 1982a, b; Pessagno
and Whalen, 1982, etc.). In Japan, Yao, Matsuda
and Isozaki (1980) were the first to document
the occurrence of an early Jurassic radiolarianassemblage from the bedded cherts of theInuyama area. Yao (1982) described these earlyJurassic radiolarians and named this assemblage
the Parahsuum simp/um Assemblage. Later,
numerous biostratigraphic studies of early*Received June 9, 1988; revised manuscript accepted
September 1, 1988.

543

Rie HORi

544

the diagnostic species of the Parahsuum simp/urn
Assemblage (Yao, 1982), first recognized anddescribed as an early Jurassic radiolarian assemblage in Japan as mentioned above.

present author carried out a supplementary andcomparative examination of radiolarians fromthree other areas, the Norikuradake area, theKuzu area and the Kuma area, Southwest Japan.

Acknowledgments

1. The Inuyama Area (lat. 3S 2S± 2' N., long.
136°S8± 2'E.)
The Mino Terrane in the Inner Zone ofSouthwest Japan is composed of a Paleozoic andMesozoic sedimentary complex consisting ofgreenstone, limestone, radiolarian chert anddetrital clastic rocks, that is interpreted as theJurassic (partly earliest Cretaceous?) subduction
complex (Wakita, 1987; Otsuka, 1988). The
Inuyama area is located in the .southwestern partof the Mino Terrane, approximately 40km northof Nagoya City (Fig. 1).
The sedimentary complex of the Inuyama
area comprises bedded chert and clastic rocks,
and it forms a large westward-plunging synform

The present author wishes to express her
thanks to Dr. Akira Yao of Osaka City University
for his helpful advice and critical reading of her
manuscript. Sincere thanks are due to Dr. Yukio
Isozaki of Yamaguchi University for his encouragement and critical reading of the manuscript.

Geologic settingThis paper deals with radiolarians mainly fromthe Inuyama area (Mino Terrane), Southwest
Japan . In addition to the Inuyama area, theot

The Iwayakannon Section

The Kurusu Section~0f)::,~9 Nori kuradake Areav{{

Kuzu Area/- 3S·N
Inuyama AreaIb

1«>1 muds tone and sands t one

a ~------~~~____140·E
L -_ _~_

chert

Figure 1. Index map of study areas (a) and geological sketch map of the Inuyama area (modified from
Kondo and Adachi, 1975 ; Yao, Matsuda and Isozaki, 1980) and study sections are shown in it (b).

863. Radiolarians from the Inuyama Area

called the "Sakahogi Syncline" of Mizutani(1964). The bedded chert, more than 100m
thick, ranges from Middle Triassic (partly late
Early Triassic?) to Early Jurassic in age. The
clastics, less than 300m thick, consist of siliceous
mudstone, mudstone, sandstone, tuffaceous
mudstone and pebbly mudstone, all of which are
Middle Jurassic in age. The Triassic to Lower
Jurassic chert and the overlying Middle Jurassic
clastics, a pair of which is tentatively called tJ:1e
chert-clastics sequence (defined by Otsuka,1985) in this paper, are tectonically repeated atleast four times in this area (Yao, Matsuda andIsozaki, 1980) as shown in Fig. 1.
The chert-clastics sequence, beautifully exposed along the Kisogawa· River in the Inuyama
area, has been investigated by many workers toestablish a Triassic and Jurassic radiolarian biostratigraphy. Yao (1972, 1979), and Ichikawa
and Yao (1976) systematically described Middle
Jurassic radiolarians (the Unuma echinatus
Assemblage) from manganese nodules occurringin a red siliceous mudstone of this area. Nakaseko and Nishimura (1979) described Upper
Triassic radiolarians from the bedded cherts ofthis area. Yao, Matsuda and Isozaki (1980)
revealed continuous faunal change of Middle
Triassic to Lower Jurassic radiolarians in a
bedded chert sequence of this area. They carefully examined an individual bedded chert
sequence in a continuous outcrop and clarified
the vertical distribution of conodonts and radiolarians. Consequently, they documented for the
first time successive occurrences of latest Triassic(Rhaetian) and early Jurassic radiolarians.
The present author studied two other continuous bedded chert sections in this area,
namely the Iwayakannon Section and the Kurusu
Section (Fig. 1). The former section ranges fromthe uppermost Triassic to Lower Jurassic and thelatter section represents only the Lower Jurassic.
I-a. Iwayakannon Section (lat. 35°25'06"N.,long. 136°58'07"E.)
This section is located on the right bank of
the Kisogawa River, approximately 1.2 km (distance in a straight line) west-southwest of the
Sakahogi railway station, in Sakahogi Town, Gifu

545

Prefecture (Fig. 1). The bedded chert of thissection, approximately 25m thick, consists of arhythmically interbedded sequence of chert andmudstone. The thickness of individual chert layer
varies from 2 to 9 cm (mostly 3.5-4 cm), andthat of mudstone layer is mostly a few millimeters, with the exception of one layer of several
centimeters in' thickness lying between IYII14
and IYII15 (Fig. 2). The strike of the bedded
chert generally trends in a north-northwest tonorthwest direction and dips steeply westward or
almost vertically. The color of the chert varies
considerably, exhibiting green, gray, red, whiteand black hues. The base of the section is sharply
bounded by a fault, resting directly on the
exposure of Upper Triassic bedded chert. At the
top of the section, on the other hand, the chert iscoherent with a pale green Middle Jurassic
tuffaceous mudstone, from which characteristic
species of the Unuma echinatus Assemblage(Yao, Matsuda and Isozaki, 1980) are obtained.
From the top of the section, characteristic
species of the Parahsuum (?) grande (= Parahsuum sp. D) Assemblage (Yao, Matsuoka and
Nakatani, 1982) are extracted. A stratigraphic
break, equivalent to one radiolarian assemblagezone (the Hsuum hisuikyoense Assemblagezone), is present between the top of the chert
and the mudstone.
A sketch map of the outcrop is shown in Fig.
2 and sampling points are marked on it. The
lithologic colunm of the section and stratigraphic
distribution of representative species in thissection are illustrated in Fig. 3.
Three early Jurassic radiolarian assemblages,
namely the Parahsuum simplum Assemblage(Yao, 1982), the A can thocircus hexagonus
Assemblage (Hori, 1987) and the Parahsuum (?)
grande (= P. sp. D) Assemblage (Yao, Matsuoka
and Nakatani, 1982) in ascending order, arerecognized in this section. Radiolarian specimens
analyzed were obtained from Samples IYII27,
IYIII1 and IYII24. These samples are biostratigraphically assignable to the lower part of the
Parahsuum simplum Assemblage-zone.
I-b. Kurusu Section (lat. 35°25'01"N., long.
136°58'02"E.)

Rie HORI

546\

LEGEND--fault~ mudstone§chertO~I====;;;;;j~M

Figure 2.

Sketch map of the outcrop of the Iwayakannon Section and sampling points marked on it.

863. Radiolarians from the Inuyama Area

547~'"<Xl"'~.... N

....

. '"

~

X

.."
...;
:; ___

w:n<lJ........ ""oo "" ><
'"
CJl
....
><

~

~<Xl
~O'I.

'" .u'" ....

;;:
'"

III

0

o '"' u. .....

'" ....
..8
0.
CJl

0

()

-r-:8,«
~

I

'"

"

III

.<::

f--5----OJ

c:

17----------------~--+_~~~~-------------------

0

U

OJ

V>
V>

'"
:;;

~

N
I

en

18----------------~--+__4_+~~-------------------

E

OJ

V>
V>

«
21------------~~~~+__4_+~---------------------

EO

22--------~~~~~-+~~----~~~n__.
LEGEND

.....
n.

7_

23 __________~~+_~~--~~~--~

faul t-24-===;:::::==t=I:=l=:I=i=t::::l=t±t=====::jrl~ mudstone ===~ chert27'----~~~~~.~~------------~========~--

26-----+--~I~~4-~~----------~

Figure 3.
species.

'"...::::>

...
OJ

3:

0

--'

:J

....EO

'EO"

:J
:J

'"
'"
''""'

.<::

""

Lithologic column of the Iwayakannon Section and stratigraphic distribution of representative

This section is located on the left bank of the
Kisogawa River, about 0.4 km north of theKurusu village, Inuyama City, Aichi Prefecture(Fig. 1). This section is composed of a rhythmically interbedded sequence of chert and mudstone. The thickness of individual chert layer
varies from 1 to 7 cm (mostly 4-4.5 cm), andthe mudstone layer is very thin (mostly 1-3mm)except for one layer (ca. lOcm thick) occurring
below KU(a)5. The Lower Jurassic portion of thebedded chert in this section, attaining 35m inthickness, is conformably underlain by an Upper
Triassic bedded chert. The top of the section iscovered with river gravels and sands. The chert
exhibits a wide range of color, varying frommostly gray and green to partly red. The bedded
chert generally strikes N 35-40"w and dips
50-60oS. In these chert layers, some sedimentary structures such as convolute lamination
are observed. Carbonate veins ((Ca,Mn)C0 3 ) of

548

Rie HORILEGEND
'-- - fault~~ mudstone§

Figure 4.

chert

Sketch map of the outcrop of the Kurusu Section and sampling points marked on it.

'"

"0

'"

0

~. "!1~.

;~JIIIIWlij11~\\I\I~II\)mlm~~~~~\11II\\IIIII~ 111\)\~I\ml\l\g~)\~11---.....--....-..-......--....---2- -------------t:
;.
0

'e.
0

A7'AAAAAAAAAAA

CC:CC:C:CC:C:C:C:CCc:c:n 0...0... 0.0... 0... o...n ro n ro CT CT...............
WQ')U1-~WN---'NW--'N--'--'

--..
c:r

--.--..
c:r CT"'--"''--'......-..
--' --'...:::::

~\

~

"'.."

A

--'

w

A

'"

c: c:
N

~

A7'

--c:c:

Ci CT

--'1O
C>

7'A;:::-::;:AAAAAAA--- -------------eee:
CT CT 0"

U1~W

CC:C:C:C:C:C:~O"DJ DJ OJ PJ OJ OJ................ U1+::>.WN--'

\

0

0

<=

- Fragme3::I

ts of Conodont-" Mis.ike 1a posthernsteini Kuzur & Mock2,;.

- Deflan recyrtium 51'. A of(Yao,1982)- Squina 01e11a(?) sp. C of Yao(1982)

'"

-

'"

Ei
<=
'"<=

en

'"~

0"
::I

po

::I

p..

to-

.....,'"
~

~.
po
"0

=;:;"
~

rn I
3

n

0.

ro

~

C

0"

rt
0

S
::I

0
....,

..,

'"
'"'"
'"
;?

"Q

~

:;:"

'"

Vl

"
- Katrom

~

::r

..,

rt

kllcusucnsis sp.

110V.

- E'tlcyrt. d.iel1um (?) 51'. C uf(Yuo,19H2)
fTI

Gl

§.

'"
~
Cl

~

St-

""~
~
~

~

~

0

.......

11Tr 111111 I
Parahsuum simp1 urn

Assemblage-zone~of Isozaki & Mustuda(1985)
sp. A of Nurchey(1984)-Acanth, ci reus hexayonus (Yao). Tril1w sp •. Zartussp •~- f1suullI

fTI

:z

:>

Assemblage-zone
Upper TrlasS1C

1a sp.

::z:,
!::>

S:
Cl
IS"
...,

--Dumitrj caella (?) sp. Ar-ro

Iptum triassicUIn

Livare- Canapt m spp.
- Gorgan ium aff. gongyloideU/" Kishida & Ilisada- Pal1t.:lll 1lium aff. kluCllse Pes.sagno & BlulIle- Goryan ium cf. gongyloideuffI Kishida & 1Ii.~:;nJa- Bipedi 51'. A-- Syring ocapsa coli forme sp. nov.
"-. Dictljo itrella sp. C of Yau(J982)- Parahs UJII simpl um Yao-- Bagatu, spp.
f. fustis De Wever- Gigi

&

!.Jv

p.

u

Parvic. nyula

Acanthoci rcus h exagonus

Assemb 1age-z(oneLower Jurasslc
u.

.j:>.

'"

550

RieHORI

several millimeters thick intruded the bedded
chert at some horizons in this section.
A sketch map of the outcrop is shown in Fig.
4 and sampling points are marked on it. The
lithologic column of the section and stratigraphic
distribution of representative species in thissection are shown in Fig. 5.
Three radiolarian assemblages of a late Triassic
to early Jurassic age, namely the Canoptum
triassicum Assemblage (Yao, 1982), the Parahsuum simplum Assemblage (Yao, 1982) and theAcanthocircus hexagonus Assemblage (Hori,
1987) in ascending order, are recognized in thissection. The latest Triassic (Rhaetian) conodont
Misikella posthernsteini Kozur and Mockoccurred together with the characteristic speciesof the Canoptum triassicum Assemblage in thelower part of the section (Samples, KU(c)3 andKU( e)3). Five biohorizons useful for age assignment in this section are the final occurrence ofM posthernsteini (KU( e)3), the first and final
occurrences of Pantanellium aff. kluense(KU(d)3, KU(b)15), the presence of Bagotum
spp. (KU(b) 11) and the first occurrence of thegenus Trillus (KU(a)5).
Radiolarian specimens analyzed were obtained
from Samples KU(b)5, KU<2>, KU(b)4 andKU < 1>. These samples belong biostratigraphically to the upper part of the Parahsuum
simplum Assemblage-zone.
2. The Norikuradake Area (lat. 36°8± l'N., long.
137°37± l'E.)
This area is about 35km west of Matsumoto
City, Nagano Prefecture, in the eastern part of
the Mino Terrane, the Inner Zone of Southwest
Japan (Fig. 1). According to Otsuka (1988), theMesozoic sedimentary complex of this area,
namely the Yukawa Complex, is composed ofJurassic chert, siliceous mudstone, mudstone andsandstone. The present samples were obtained
from a bedded chert in the chert-clastics
sequence of this complex.
3. The Kuzu Area (lat. 36°26±4'N., long. 139°
35± 4'E.)
This area is about 85km north of Tokyo, in

the Ashio Terrane that is regarded as the easternextension of the Mino Terrane (Fig. 1). Igo andNishimura (1984) reported early Jurassic radiolarians from continuous chert sequences of the"Adoyama Formation". The present samples
were obtained from bedded cherts of this"formation"
4. The Kuma Area (lat. 32°21± 4'N., long. 130°37±4'E.)
This area is situated along the midstream of
the Kumagawa River, Kumamoto Prefecture,
Kyushu, in the Chichibu Terrane, the Outer Zoneof Southwest Japan (Fig. 1). The biostratigraphyof Late Paleozoic and Mesozoic radiolarians has
been studied in this area and approximately 20
radiolarian zones from the Permian to Cretaceousinterval were proposed by Nishizono et al.
(1982), Nishizono and Murata (1981), Sato andNishizono (1983) and Sato, Murata and Yoshida(1986). The present samples were obtained frombedded cherts and mudstones in this area.

Methods and materials
A cRert sample weighing about 0.6 kg wascollected from each single layer of bedded chert.
Samples were treated with a 5% solution ofhydrofluoric acid for 18-20 hours and thenrinsed with tap water. Residues retained on a74-,um opening screen were boiled in asolution containing the equal volume of 36%hydrochloric acid, 61 % nitric acid and water fora few minutes to dissolve any remaining organic
matter and then washed thoroughly if further
cleaning is needed. More than one glass slide
made for residues of every sample was investigated by a transmitted light microscope. Residues containing well-preserved radiolarians aswell as those representing any important biohorizon, were dried, and then 100-200 specimens were hand-picked with the aid of binocular
microscope and observed by a scanning electron
microscope. However, specimens from thebedded cherts treated in this study are notpreserved well enough to describe their internal
structures because of strong recrystallization and863. Radiolarians from the Inuyama Area

replenishment with silica. The type and figured
specimens have been deposited and registered in
the Department of Geosciences, Osaka City
University. In the section of Systematic
paleontology and figure captions, the OCU MR
number refers to the registration number of thespecimen at the reposition. The number following F or FL represents photograph number, andother unaccompanied number refers to individual
specimen.
Systematic paleontology
Subclass RADIOLARIA Miiller, 1858
Superorder POLYCYSTINA Ehrenberg, 1838,
emend. Riedel, 1967
Order NASSELLARIA Ehrenberg, 1875
Family SYRINGOCAPSIDAE Foreman, 1973
Type genus: Syringocapsa Neviani, 1900, p.
662.
Diagnosis: Original definition by Foreman(1973, p. 265) "Cyrtoidea with the multiple
segments of the proximal part very small and thesingle segment of the distalmost part very large
and expanded. A terminal tube mayor may not
be present. None of the proximal segments are
hidden and the cryptocephalic and cryptothoracic nassellaria of Dumitrica (1970) are
therefore excluded."Remarks: foreman (1973) originally defined
this group belonging to the subfamily Syringocapsinae. Afterward, Pessagno (1977, p. 90)
suggested that this subfamily should be treated asa family.
Constituent genera: Dibolachras Foreman,
1973; Podobursa Wisniowski, 1889; Podocapsa
Riist, 1885; Sethocapsa Haeckel, 1881; Syringocapsa Neviani, 1900; Trisyringium Vinassa, 1901;
Urocyrtis Pantanelli, 1880; Gigi De Wever,
1982a; Katroma Pessagno and Poisson, 1981,
emend. De Wever, 1982a.

Genus Katroma Pessagno and Poisson, 1981,
emend. De Wever, 1982
1981 Katroma Pessagno and Poisson, p. 62.

551

1982a Katroma Pessagno and Poisson, emend. De
Wever, p. 193.
1982b Katroma Pessagno and Poisson, emend. De Wever- De Wever, p. 303.
1987 Katroma Pessagno and Poisson - Yeh, p. 79

Type species: Katroma neagui Pessagno andPoisson, 1981, p. 62 (pI. XII, figs. 1-5, pI. XV,
fig. 3.)
Diagnosis: Test composed of 3 or 4 chambers,
cephalis, thorax, abdomen and/or postabdomen,
and tube. Outline of test forming spindle-shapewith radial spines on the most expanded part oftest. Cephalis hemispherical with some horns or abranched apical horn. Thorax forming truncatedcone. Cephalo-thorax conical without developed
strictures. The last chamber, abdomen or a
post-abdominal chamber, hemispherical larger
than previous chambers and with solid spines
radially arranged on the medial part. Tube
porous and elongated conical to cylindrical.
Remarks: Pessagno and Poisson (1981, p. 62)
defined this group as a new genus which differsfrom Podobur.sa Wisniowski by having an open
tube on its final post-abdominal chamber. De
Wever (1982a, b) emended its definition,
pointing out that most of the species belonging
to this genus possess closed tubes. Therefore, theterminal form of the tube is not an importantcharacter to distinguish Katroma from Podobursa. De Wever indicated that this genus differsfrom Podobursa by having three chambers andspines (apical and others) on cephalis. The
number of chambers, however, is not significant
to distinguish Katroma from Podobursa, becausesome species of Podobursa (e.g., Podobursa
tricola Foreman, 1973) possess three chambers as
those of Katroma do. Accordingly, Katroma isdistinguished from Podobursa by having pluralspines and/or a branched spine, or both on
cephalis and by lacking developed strictures on
the proximal portion of the test.
Katroma is also morphologically similar to
Dibolachras Foreman, 1973, Podocapsa RUst,
1885 and Gigi De Wever, 1982a. Dibolachras is
distinct from Katroma in the same characters as
Podobursa by lacking plural spines, or a branched
one, on cephalis and by having strong strictures

Rie HORI

552

1b

1c

2b

3

4

_

2c

863. Radiolarians from the Inuyama Area
Table 1.

Measurements of Katroma kurllsllensis, sp. nov.

Specimen

Fig.

KU<2>1/11 No.l(36.4x91.8)
Kli<2>I/II No.1(36.0x93.0) 1-4* KU(b)5No.1(46.8x89.4) 1-5
KU<2>-24
KU<2>-23** KU<2>-21
1-la-1c
KU<l>-ll
KU<1>-12
KU(b)4-11
1-2a-2c
KU(b)4-21
KU(b)511-15
KU(b)511-16
KU(b)511-22
KU(b)511-31
KU(b)511-35
Average
Maximum
Minimum** : Holotype.

*

553

Width

Total Height

Length ofTube

Length of
Spine

Number of
Branch

117.1
137.4
118.2
116.4
112.5
120.4
100.7
119.1
132.2
128.3
132.9
128.9
75.0
78.3
117.1

321. 4+316.6+
406.4
286.2+
349.3
307.2+
271. 1
315.8
312.5
283.6
306.6+
334.2
203.3
277.6
284.9

135.3+
110.7+
209.6
118.4+
178.3
125.0+
122.4
145.4
137.5
136.8
132.9+
148.0
89.5
125.7
125.7

23.0
26.7
38.3

4
3
4
37
3
4
37

115.6
137.4
75.0

305.1
406.4
203.3

136.1
209.6
89.5

26.3
24.3
21. 7
24.8
27.6
22.4
27.0

3
37
4
47
37
3
3

26.2
38.3
21. 7

Para typeon the proximal portion of the test. Katroma
differs from Podocapsa by lacking porous wings
and by having a branched apical horn. Gigi canbe discriminated from Katroma by lacking circumferential spines.
Constituent species: Katroma neagui Pessagno
and Poisson, 1981, emend. De Wever, 1982a;
Katroma bicomus De Wever, 1982a; Katroma sp.
A of De Wever (1982a); ? Katroma sp. 2 of De
Wever (1982a); Katroma milloti Schaaf, 1984;
Katroma clara Yeh, 1987; Katroma sp. B of Yeh(1987).
Katroma kurusuensis Hori, sp. nov.
Figures 6-1a-5

1986 Katroma sp. M - Hori, fig. 7.

Description: Test composed of 3 or 4
chambers. Cephalis with an apical horn having 3
or 4 branches; branches, triangular in crosssection. Cephalo-thorax conical without developing stricture. Abdomen or a post-abdominal
chamber polygonal in axial section at most
expanded portion. Six to 12 circumferential
spines projected radially from the most expanded
portion of test; spines solid, and triangular incross-section. Terminal tube cylindrical to conical; distal end of tube closed. Meshwork consisting of circular to polygonal pore frame; pores
becoming elliptical distally.
Measurements: (in micrometer; based on 15
specimens shown in Table 1).
Remarks: Katroma kurusuensis sp. nov. morphologically resembles Katroma clara Yeh, but
the former species differs from the latter species~ Figure 6.
Katroma kurusuensis, sp. nov.
Ia-c. Holotype, oeu MR 4000, KU <2>-21(b) and (c) stereoscopic pair, oblique apical view (a) x 150, (b), (c) x 300
2a-c. oeu MR 4002, KU(b)4-11 (b) and (c) stereoscopic pair, oblique apical view (a) x 150, (b), (c) x 225
3. oeu MR 4003, KU(b)4-12, oblique basal view, x 225
4. oeu MR 4004, KU<2> IIII No.1 (36.0x93.0), x 187
5. Paratype, oeu MR 4001, KU(b)5 No.1 (46.8x89.4), x 187
All figures are scanning electron micrographs except for 4, 5 transmitted light photomicrographs.

554

RieHORI

by having longer and bladed circumferential
spines, and by possessing a horn with 3 to 4
branches; branches are triangular in cross-section.
K. kurusuensis differs from both K. neagui
Pessagno and Poisson and K. bicornus De Weverby possessing an apical horn with 3 or 4
branches; branches are triangular in cross-section.
K. sp. M (Hori 1986, p. 52, fig. 7) is a provisionalname given to this species.
Etymology: This name is derived fro~ thetype locality of this species, Kurusu village,
Inuyama City, Aichi Prefecture.
Type species: Holotype, OCU MR 4000
(F02670) (KU<2>-21) from the Kurusu Section. Paratype, OCU MR 4001 (FL002-19)(KU(b)5 No.1 (46.8x89.4)) from the Kurusu
Section.
Type locality: The Kurusu Section, Inuyama
area, Inuyama City, Aichi Prefecture, central
Japan.
Occurrence: Southwest Japan; Inuyama area
(Mino Terrane), Kuma area (Chichibu Terrane),
Kuzu area (Ashio Terrane).
Range: Middle Early Jurassic (Sinemurian toPliensbachian) .
In the Kurusu Section, the horizon of the firstoccurrence of this species (Sample KU(b )5) is
9.58m above the horizon of occurrence of
Bagotum spp. This implies that K. kurusuensis
firstly appeared later than species of Bagotum.
According to Pessagno and Whalen (1982), theoldest species of Bagotum (Bagotum erraticum
Pessagno and Whalen) appeared in the Sinemurian part of the Kunga Formation (QC 549),
Queen Charlotte Islands, British Columbia,
Canada. Therefore, the first appearance of K.
kurusuensis was during a post-Sinemurian or
Sinemurian time. In the UC Section of theInuyama area (Hori, 1986), the first occurrence
horizon of this species is below the final occurrence horizon of Pantanellium cf. danaense
Pessagno and Blome, 1980. P. danaense wasreported from the Rhaetian(?)-Hettangian interval and the upper Upper Sinemurian part
(Echioceras raricostatum Zone) of the Kunga
Formation (Pessagno and Blome, 1980). Taking
the above-mentioned facts into account, K.

kurusuensis presumably first appeared during theSinemurian.
In both the Kurusu and the Iwayakannon
Sections, the final occurrence horizon of K.
kurusuensis is below the first occurrence horizonof the genus Trillus. However, in the UC Section(Sample UC6), K. kurusuensis (= K. sp. M)
occurred together with Trillus cf. elkhornensis
Pessagno and Blome. The co-occurrence of
Trillus elkhomensis and Katroma was reported
from the Upper Pliensbachian part of the Nicely
Formation (Amaltheus margaritatus Zone Pleuroceras spina tum Zone), eastern Oregon(Pessagno and Blome, 1980). Thus, the range ofK. kurusuensis probably extends upwards at least
to the upper Pliensbachian.
Katroma sp. N
Figures 7-1-3

1986 Katroma bicornus De Wever - Sashida et al., p.
42-43, fig. 5-1
1987 Katroma sp. B - Yeh, pI. 5, fig. 20, pI. 6, fig. 3.

Remarks: This species is distinguished from K.
kurusuensis. sp. nov. and K. bicomus De Wever inhaving only an apical horn of varying forms. K.
sp. N has an apical horn which bears very small
spines at its medial portion (Fig. 7-3).
Katroma sp. N differs from K. neagui
Pessagno and Poisson in having solid and bladed
circumferential spines.
Measurements: (in micrometer; based on 8
specimens shown in Table 2).
Occurrence: Southwest Japan; Inuyama area
(Mino Terrane), Kuma area (Chichibu Terrane).

Genus Syringocapsa Neviani, 1900
1900 Syringocapsa Neviani, p. 662.
1901 Trisyringium Vinassa, p. 507.
1954 Trisyringium Vinassa - Campbell, p. D142.
1973 Syringocapsa Neviani - l'oreman, p. 268.
1975 Syringocapsa Neviani - Foreman, p. 617.
1979 Syringocapsa Neviani - De Wever et al., p. 91.
1981 Syringocapsa Neviani - Petrushevskaya, p. 188.
1982b Syringocapsa Neviani - De Wever, p. 290-291.
April 1984 Syringocapsa Neviani - Blome, p. 52-53.
December 1984 Syringocapsa Neviani - Baumgartner,

863. Radiolarians from the Inuyama Area

555

Figure 7. Katroma sp. N.
1. oeu MR 4005 , KU <2> I/II No.1 (38 .4x95.0) , x 15 5
2. oeu MR 4006, KU<2>I/II No.1 (38.2x92.0), x 15 5 3. oeu MR 4007, KU(b)5 - 16 , x 300
1,2 are transmitted light photomicrographs except for 3, scanning electron micrograph .

Table 2.

Specimen

KU<2>I/I I No.1(38.4x9S.0)
KlJ <2> I/II No.1(38.2x92.0)
KlJ(b)5-04
KU(b)S-07
KU(b)5-09
KlJ( b) 511 - 18
KlJ(b)SII-28
KU(b)SII-38
Average
Maximum
Minimum

Measurements of Katroma sp. N

Fig.

Width

Length of
Cephalic Part

Total He ight

Length ofTube

Length of
Spine

7-1
7-2
7-3

109 . 6
106.4
109.9
79 . 6+
152.0
8l. 6
110.5
97 . 4+

176.5
195.7
189.5
209 . 2
230.3
184.9
184.9
190.8

317.6+
322.5+

l3l. 6+128.9+

33. 7
18.7+

307 .9

123.0

30.3
27.0
46.1

307.2

ll6.4

105.9
152 . 0
79.6+

195.2
230.3
176. S

313.8
322.5+
307.2

125 .0131.6+
ll6.4

p.786.

Type species: Theosyringium robustum
Vinassa, 1900, p. 343 (pI. 3, fig. 30), bymonotype.
Diagnosis: Test comprising 2 to 4 chambers,
cephalis, thorax or abdomen, or both, possibly
more chambers, and closed tube. Outline of test
forming spindle-shape without radial spines , withsome strictures weakly or strongly developing at
joints of chambers. Cephalis with or without an

SO.O

34.3

SO.O
18.7+

unbranched apical horn. The last chamber most
expanded.
Remarks : Since Foreman (1973) treated thegenus Syringocapsa as the type genus of thesubfamily Syringocapsinae, several species ofSyringocapsa, including some new species, havebeen described. According to the original description by Neviani (1900), Syringocapsa is defined
to possess 3 chambers, however, most of thespecies belonging to Syringocapsa possess morethan 3 chambers. Therefore, syringocapsids with

RieHORl

556

2 to 4 chambers are all included in the genus
Syringocapsa.
Syringocapsa differs from Gigi De Wever,
1982a by lacking a crown-like apical horn andspines on cephalis. This genus differs from
Dibolachras Foreman, 1973, Katroma Pessagno
and Poisson, 1981, and Podobursa Wisniowski,
1889 by lacking spines on the most expandedchamber. Syringocapsa differs from Podocapsa
RUst, 1885 by lacking porous wings.

Syringocapsa coliJorme Hori, sp. nov.
figures 8-1-10
March 1982 Syringocapsa sp. C - Yao, pI. 4, fig. 16.
June 1982 Syringocapsa sp. C - Yao et al., pI. 2, fig.
14
1983 Syringocapsa sp. C - Yao, fig. 2-18.
March 1983 Syringocapsa sp. C of Yao - Ishida, pI. 1,
fig. 10.
? 1985Katroma triangularis Kishida and Hisada, pI. 3,
fig. 6,7.
1986 Katroma sp. - Matsuoka and Yao, pI. I, 1.
1986 Syringocapsa sp. C (Yao, 1982) - Hori, fig. 6-5
December 1986 Syringocapsa sp. A - Yoshida, p. 17,
pI. 6, fig. 11.

Description: Test consisting of 2 or 3 chambers, long, slender, spindle-shaped with closed
tube. Cephalis small, having a solid, long apicalhorn, which terminating in a point. Apical hornsmooth, mostly circular in cross-section. Some
specimens possessing a slender, weak-bladed
apical horn. Cephalo-thorax conical forming tearshaped with weak strictures. The distalmost
chamber expanded, decreasing rapidly in width
at joint of the tube. Tube, long, slender, conical,
closed, and terminating in a pointed spine.
Meshwork of test consisting of polygonal tocircular pore frames. Average ratio of height tomaximum width, approximately 3.9: 1.
Measurements: (in micrometer; based on 29
specimens shown in Table 3).
Remarks: Syringocapsa coliJorme sp. nov. isvery similar to Gigi sp. aff. G. Justis De Wever(described below) in its size and shape, but theformer is distinguished from the latter bypossessing a short, conical tube, and a larger
proximal portion of test and a simple long hornwithout branches. Also, the latter species differsfrom the former by having delicate spine(s) on
cephalis and fewer segments.
G. Justis De Wever is distinguished from S.
coliforme by the same characters as those of G.
aff. fustis described below and by having a
globular proximal portion of test and smoothersurface.
S. coliforme also morphologically resembles S.
sp. A of Yao (pI. 3, fig. 12 in Yao, 1982) and S.
sp. B of Yao (pI. 4, figs. 14, 15 in Yao, 1982).
However, it can be discriminated from the lattertwo species by the larger average ratio of height
to width. That ratio of S. coliforme is about 3.9,
whereas that of S. sp. B is about 1.7 and S. sp. A
is about 2.6.
Etymology: The species name is derived fromthe Latin compound word, colus+formis,
meaning spindle-shaped.
Type specimen: Holotype, OCU MR 4008
(FLOOl-21) (IYII27II No.1 (37.3x89.9)) fromthe Iwayakannon Section. Paratype, OCU MR
4016 (FOl724) (IYII27II-19) from the Iwayakannon Section.
Type locality: The Iwayakannon Section,
Inuyama area, Sakahogi-cho, Kamo-gun, Gifu
Prefecture, central Japan.
Occurrence: Southwest Japan; Inuyama area
(Mino Terrane), Norikuradake area (MinoTerrane), Kuzu area (Ashio Terrane).
Range: Latest Triassic (Rhaetian) to early
Early Jurassic (Sinemurian ?).
In the Kurusu Section, the horizon of the firstoccurrence of S. coliforme (Sample KU( c)l) is
situated at 22cm above the horizon of the final
occurrence of the latest Triassic conodont
Misikella posthernsteini (Sample KU( e)3) (Fig.
5). At the horizon of Sample KU( e)2, S. coliforme occurred with such late Triassic radiolarians, as Squinabolella (?) sp. C of Yao (1982)
and Livarella sp. These facts indicate the horizonof the first occurrence of S. coliJorme to be in
the upper Triassic. Additionally, S. coliforme
also occurred immediately below the horizon of
the last occurrence of Pantanellium aff. kluenseof Pessagno and Blome (1980). According toPessagno and Blome (1980), P. aff. kluense863. Radiolarians from the inuyama Area557

1....---- 2----- 6----- 8Figure 8. Syringocapsa coliforme, sp. nov.
1. Holotype, OCU MR 4008, IY1l2711 No.1 (37.3x89.9) 2. OCU MR 4009 , lY1l2711 No.1 (4 1.1x98.4) 3. OCU
MR 4010 , IY1l2711 No.1 (37.0x89 .7) 4. OCU MR 4011 , lY1l2 7Il No. 1 (37.3x90.7) 5. OCU MR 4012,
lYII2711 No.1 (37.7x9 1.1) 6. OCU MR 4013 , lYII27Il No.1 (42.0x97.7) 7. OCU MR 4014 , lY1l271l No.1
(40.6x91.3) 8. OCU MR 4015 , IY1l27Il No.1 (42.1x90 .9 ) 9. Paratype , OCU MR 4016 , IY1l271-19 10. OCU
MR 4017 , IYII271-29.
All figures , x155 , are transmitted light photomicrograph s except for 9,10, scanning electro n micrographs.

occurs from the Rhaetian (?) to Hettangian partof the Kunga Formation of Queen Charlotte
Islands. Therefore, S. colzforme probably ranges
at least from the Rhaetian to the Hettangian.
The horizon of the final occurrence of S.
coliforme is 230cm above the horizon of

KU(b)ll with Bagotum spp. According toPessagno and Whalen (1982), the oldest species of
Bagotum was reported from the Sinemurian. In
the Iwayakannon Section, the horizon of the
final occurrence of S. coliforme is roughly
assigned to the horizon of co-occurrence of theRie HORI

558
Table 3.

Measurements of Syringocapsa coliforme. sp. nov.

Fig.

Length of
Horn

Lc

Ht

Width

8-1
8-3
8-4
8-5

57.2
52.9
56.1
48. 1
48. 1+
51. 9
37.4+
36.4+
39.0+
32.6+
56. 7
41. 2+
53.5
58.3
58.3
57.8
57.8
44.9
44.4+
56.1
63.6
55.1
50.8
35.3+
77.0
63.8
48.0
64.5
64.5+

193.6
197.9
206.4
198.9+
197.9+
197.3
193.0+
197.3+
183.4+
195.2+
210.2
198.9+
194.7
211.2
170.6
220.3
188.2
190.4
209.6+
181. 3
198.4
215.0
207.5
189.8+
223.0
213.2
167. 1219.4
219.4+

349.7
378.6
389.8
376.5+
379.1+
325.1+
381.3+
385.6+
315.5+
388.2+
373.3+
395.2+
315.5+
380.2
324.6
400.5+
385.0
335.3+
366.8+
325.1+
394. 7402.1+
363. 1356.7+
404.0
367.8+
324.3+
438. 7432.3+

89.8 3.89
93.0 4.07
89.3 4.37
85.6 4.40+
107.0 3.55+
103.2 3.15+
89.8 4.24+
103.7 3.72+
96.3 3.28+
86.1 4.51+
82.9 4.50+
100.0 3.95+
96.3 3.28+
107.0 3.56
95.7 3.39
93.6 4.28+
70.1+ 5.5087.2 3.85+
109.6 3.35+
90.4 3.60+
85.6 4.61
96.3 4.18+
102.7 3.54
87.7 4.07+
98.7 4.09
105.9 3.47+
90.8 3.57+
96.8 4.53
90.3 4. 79+

Average
Maximum
Minimum

52. 1
77.0
32.6+

199.6
223.0
167. 1370.8
438.7
315.5+

94.2 3.98
109.6 5.5070.1+ 3.15+** : Holotype* : Paratype

Lc
Ht

Specimen** IY27I1 No.1(37.3x89.9)
IY27I1 No.1(37.0x89.7)
IY27I1 No. 1(37.3x90. 7)
IY27I1 No. 1(37.7x91. 1)
IY27I I No.1 (37.1 x94. 5)
IY27I1 No.1(37.8x94.8)
IY27II No.1(37.9x95.9)
IY27II No. 1(37.2x97. 7)
IY27I1 No.1(36.9x96.5)
IY27II No.1(39.5x88.8)
IY27II No.1(39.4x89.4)
IY27I I No.1 (40.1 x90. 6)
IY27II No. 1(40. 7x90.8)
IY27I1 No.1(40.6x91.3)
IY27I1 No.1(40.9x91.8)
IY27II No.1(41.5x92.0)
IY27II No.1(42.3x88.6)
IY271I No.1(42.0x89.9)
IY27II No. 1(42. 1x90.9)
IY27II No. 1(43. 7x92.5)
IY27I1 No.1(42.4x94.3)
IY27II No.1(43.2x91.4)
IY27I1 No. 1(42.0x97. 7)
IY27I1 No. 1(41. 1x98.4)
IYI 12411-20
IYII24II-19
IYII24II-11* IYII27I-19
IYII27I-29

8-7

8-8

8-6
8-2

8-9
8-10

genera Gigi and Katroma. In Turkey, the cooccurrence of Gigi and Katroma was reported
from Sample 1662-D (of Pessagno and Poisson,
1981 and De Wever, 1982a) which was obtained
from beds a few ten of meters below a bed
bearing Late Pliensbachian ammonites (DeWever, 1982a). Pessagno and Poisson (1981)
assigned the Turkish radiolarian assemblage ofSample 1662-D to the Early Pliensbachian age on
the basis of their radiolarian data. Therefore, it is- positive that the range of S. coliforme extends to
the Sinemurian.
Considering the above-mentioned facts, S.
coliforme is regarded to range at least from the

H/w

Length of cephalic part
Total heightlatest Triassic (Rhaetian) to Sinemurian, but its
occurrence from the Pliensbachian is still uncertain.
Genus Gigi De Wever, 1982
1982a Gigi De Wever, p. 194.
1982b Gigi De Wever - De Wever, p. 340.

Type species: Gigifustis De Wever, 1982
Diagnosis: Test comprising 2 to 3 chambers,
cephalis, thorax or abdomen, or both and closed
tube, without radial spines. The proximal portion
subspherical, having smooth surface and circularpores with a crown-like apical horn and thorn(s).

863. Radiolarians from the Inuyama Area

559

Tube porous and elongated cylindrically, sometimes weakly expanded near the distal end.
Remarks : The genus Gigi was originally described under the family Eucyrtidiidae Ehrenberg,
1847 by De Wever (198 2a). La ter, he treated thisgroup as incertae sedis (De Wever, 1982b). The
present author classifies the genus Gigi to thefamily Syringocapsidae Foreman. According to
De Wever's definition, the genus Gigi has twosegments with closed tube, cephalis with acrown-like or needle-like apical horn, andthorn(s). However, it is difficult to distinguishspecies of Gigi from those of Sy ringocapsa solely
by the possession of a needle-like apical horn.
Constituent species: Gigi Justis De Wever,
1982a; Gigi elliptica (Kishida and Hisada, 1985);
Gigi triangularis (Kishida and Hisada , 1985); Gigi
sp. aff. G. Justis (in this paper)

Gigi sp. aff. G. Justis De Wever, 1982
figures 9-1 ,2

Remarks: Gigi aff. Justis differs from G. Justis
by having a longer apical horn and much longer
cephalo- thorax with polygonal pore frames ,whose surface is not smooth. This form also
morphologically resembles Syringocapsa co liforme, sp. nov. The former is distinguished fromthe latter by having a cylindrical tube, globular
proximal portion of the test and branched apicalhorn.
Occurrence: Southwest Japan ; Inuyama area
(Mino Terrane), Norikuradake area (MinoTerrane), Kuzu area (Ashio Terrane).

Extended remarks
In this section, the phylogenic relationshipamong four species of the family Syringocapsidae
described in this paper , i e. Katroma kurusuensis
sp. nov. , K. sp. N, Gigi sp. aff. G. Justis andSy ringocapsa coli/orme, sp. nov. , is discussed on
the basis of their morphology and biostratigraphic distribution. Also mentioned is the biostratigraphic utility of the species of Katroma forestablishing a world-wide correlation.
Since some or various species of the genera

Figure 9. Cigi sp . aff. C. Justis De Wever
1. OCU MR 4018 , lYlVI - 28. 2. OCU MR 4019 ,IYlVl -29. Figur es, x155 , are scanning elec tron micrographs.

Syringocapsa, Katroma and Gigi from the Lower
Jurassic of Southwest Japan morphologicallyresemble one another , it is assumed that
there are phylogenic relationships among these
species. In particular, Syringocapsa coli/orme isvery similar to Gigi sp . aff. G. Justis in its size andstructure of the shell. In all the sections dealt
with in this paper, S. coli/orme always appeared
earlier than G. aff. Justis (Figs. 3, 5). From thesefacts , it is possible that S. coli/orme gave rise to
G. aff. Justis and furthermore that Sy ringocapsa
coli/orme is the ancestor of Gigi. Dumitrica(personal communication? to De Wever ; See De
Wever , 1982a, b) insisted that Gigi gave rise to
Katroma. The present author, however , disagrees
with his opinion, because Katroma made its first
appearance approximately at the same time as
Gigi in those continuous sections of the Inuyama
area . In addition, species belonging to Katroma
are morphologically more similar to some species
of Syringocapsa (e. g., S. co li/orme) than to thoseof Gigi, particularly in the number of chambers

560

RieHORI

and shape of shell. By comparing the first
appearance horizon of these species, the present
author tentatively regards that both Gigi and
Katroma branched off from Syringocapsa during
an early Early Jurassic time.
Because of the reasons mentioned below, taxa
of Katroma are important to establish a correlation of the Lower Jurassic radiolarian zones ofSouthwest Japan with those of the North
American and other regions; 1) Taxa of Katroma
are cosmopolitans in the Lower Jurassic, reported from various localities, such as Turkey,
Greece, eastern U.S.S.R. (Amur area), North
America and Southwest Japan (Pessagno andPoisson, 1981; De Wever, 1982a, b; Tikhomirova,
1985; Murchey, 1984; Isozaki, 1984; Kishida and
Hisada, 1985, 1986; Hori, 1986; Sashida, Tonishi
and Igo, 1986; Sato, Murata and Yoshida, 1986,
etc.); 2) Occurrence and frequency distributionof Katroma are independent of host rock lithology. Species of Katroma occur from chert,
siliceous mudstone, mudstone and limestone; 3)
They are short ranged and co-occur with diagnostic species of the Lower Jurassic radiolarianzones. For example, the range of K. kurusuensis
is probably limited in the Sinemurian and Pliensbachian and co-occurs with diagnostic species of
the Parahsuum simplum Assemblage-zone (Yao,
1982), as mentioned above, one of the importantearly Jurassic radiolarian assemblage-zones inSouthwest Japan.
These reasons form the basis to consider thatspecies of Katroma are the good marker taxa forinternational correlation of Early Jurassic radiolarians. In Southwest Japan, the occurrence of
these species is limited in the upper part of the
Parahsuum simplum Assemblage-zone. Thus, theupper part of the Parahsuum simplum
Assemblage-zone roughly corresponds to thefollowing Lower Jurassic radiolarian zones ofprevious authors, MH-1 of Murchey (1984) in
Calfornia, Katroma (?) cf. bicomus - Lithocampe sichotica Complex of Tikhomirova (1985)
in the Amur area (U.S.S.R.) and Zones 04 - 01?
of Pessagno et al. (1987) in North America.
Among them, Zones 04 - 01 established by
Pessagno et al. (1987) are defined on the basis ofco-occurrence of radiolarians and ammonites in
the Queen Charlotte Islands, British Columbia
and east-central Oregon; e.g. the radiolarians of
the Zone 04 occur with the lower Sinemurian
ammonites, while the top of the Zone 01 lies
within the Toarcian. According to these data atpresent, therefore, the age of the upper part of
the Parahsuum simplum Assemblage-zone is probably assigned to late Sinemurian to late Pliensbachian, and furthermore may extend down toearly Sinemurian and/or up to early? Toarcian.
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Cushmlln Found. Foram. Res., Spec. Pub., no. 23,
p.1-18.
- - and Poisson, A. (1981): Lower Jurassic radiolarian
from the Gumuslu Allochton of southwestern
Turkey (Taurides Occidentales). BulL of theMineral Research and Exploration Institute ofTurkey, no. 92 (1979),p. 47-69,15 pis.
- - and Whalen, P. A. (1982): Lower and Middle
Jurassic Radiolaria (mluticyrtid Nassellariina) from
California, east-central Oregon and the Queen
Charlotte Islands, B. C. Micropaleontology, vol. 28,
no. 2, p. 111-169,13 pis.
Petrushevskaya, M. G. (1981): Radiolarii otroyada
Nassellaria mirovogo okeana. Izd. Zool. Inst.,
Nauka, Leningrad, no. 128, 405 p., 600 figs. (inRussian).
Ri.ist, D. (1885): Beitrage zur Kenntniss der fossilen
Radiolarien aus Gesteinen des Jura. Palaeontographica, vol. 31 (ser. 3, vol. 7), p. 268-321, pis.
26-45.
Sashida, K. (1988): Lower Jurassic multisegmented
Nassellaria from the Itsukaichi area, western partof Tokyo Prefecture, central Japan. Sci Rep. Inst.
Geosci, Univ. Tsukuba Sec. B, vol. 9, p. 1-27, 4pis.
- - , Tonishi, K. and Igo, H. (1986): Lower Jurassic
radiolarians from the Takarazawa area of Itsukaichi
Town, Tokyo Prefecture, central Japan. News ofOsaka Micropaleontologists, Spec. VoL, no. 7, p.
35-43, 5 figs. (in Japanese with English abstract).
Sato, T., Murata, M. and Yoshida, H. (1986): Triassic toJurassic radiolarian biostratigraphy in the southernpart of Chichibu terrain of Kyushu, Japan. Ibid.,no. 7, p. 9 -23, 17 figs. (in Japallese with English
abstract).
- - and Nishizono, Y. (1983): Triassic and Jurassic
radiolarian assemblages from two continuous sections in the Kuma maSSlI, Kyushu, Japan. News ofOsaka Micropaleontologists, no. 11, p. 33 -47, 3
pis. (in Japanese with English abstract).
Schaaf, A (1984): Les Radiolaires du Cretace inferieur
et Moyen: Biologie et Systematique. Sci Geol.
BulL Mem., no. 75, 189 p., 38 pis.
Tikhomirova, L. B. (1985): Jurassic radiolarians of therar East U.S.S.R. In Westerman G.E.G. ed.,Jurassic Biogeography and Stratigraphy of East

U.S.S.R., I.G.C.P. Project #171: Circum-PacificJurassic Special paper, no. 10. p. 18-21.
Vinassa de Regny, P. E. (1900): Rocce e fossili dei
Dintorni di Grizzana e di Lagaro nel Bolognese.
Soc. Geol. Ital. Boll., vol. 19, no. 2, p. 321-348,
pI. 3 (in Italian).
-(1901): Radiolari Cretacei dell'lsola di Karpathos.
Mem. R. Accad. Sci 1st. Bologna, ser. 5, vol. 9,(1901-1902), p. 497-512,1 pI. (in Italian).
Wakita, K. (1987): The occurrence of Latest JurassicEarliest Cretaceous radiolarians at the HidaKanayama area in the Mino terrane, central Japan.
Jour. Geol. Soc. Japan, vol. 93, no. 6, p.
441-443, 1 pI. (ill Japanese).
Wisniowski, T. (1889): Beitrag zur Kenntniss der
Mikrofauna aus den oberjurassischen reuersteinknollen der Umgegend von Krakau. Jahrb. Kaiserl.kgl. Geol. Reichsanst., Wien, Jahrg. 1888, vol. 38,
p. 657-702, pI. 12-13.
Yao, A. (1972): Radiolarian Fauna from the Mino Beltin the Northern Part of the Inuyama Area, Central
Japan. Part I. Spongosaturnalids. Jour. Geosci,
Osaka City Univ., vol. 15, p. 21-64, 11 pIs.
- - (1979): Radiolarian rauna from the Mino Belt in
the Northern Part of the Inuyama Area, Central
Japan. Part II: Nassellaria 1. Ibid., vol. 22, p.
21-72,12 pIs.
(1982): Middle Triassic to Early Jurassic Radiolarians from the Inuyama Area, Central Japan.
Ibid., vol. 25, p. 53-70, 4 pis.
(1983): Late Paleozoic and Mesozoic Radiolarians
from Southwest Japan. In siliceous Deposits in the
Pacific Region. lijima, A, Hein, J.R. and Siever, R.
eds., Elsevier, Amsterdam, p. 361-376, 3 figS.
- , Matsuda, T. and Isozaki, Y. (1980): Triassic andJurassic Radiolarians from the Inuyama Area,
Central Japan. Jour. Geosci, Osaka City Univ., vol.
23, p. 135-154, 3 pis.
- , Matsuoka, A. and Nakatani, T. (1982): Triassic
and Jurassic radiolarian assemblages in Southwest
Japan. News of Osaka Micropaleontologists, Spec.,
VoL, no. 5, p. 27-43, 4 pis. (in Japanese withEnglish abstract).
Yell, K. Y. (1987): Taxonomic studies of Lower
Jurassic Radiolaria from East-Central Oregon. Nat.
Museum Nat. Science, Spec. Pub., no. 2, 169 p., 30
pis.
Yoshida, H. (1986): Upper Triassic to Lower Jurassic
Radiolarian Biostratigraphy in Kagamigahara City,
Gifu Prefecture, Central Japan. 1. Earth Sci
Nagoya Univ., vol. 34, p. 1-21, 17 pis.

863. Radiolarians from the Inuyama Area

563

Aichi ~~, Gifu ~Jj!, Inuyama *llJ, Iwayakannon !5!UIl11f, Kisogawa *~JII, Kuma rJ(lI!\',
Kurusu ~~, Kuzu :fjg1=., Mino ~i81, Nagoya ~tll"£, Norikuradake ~¥'J(ffT, Sakahogi ~:m,Unuma .16.

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Syringocapsa coliJorme 0) 2 ~~ t. Katroma sp, N, Gigi sp, afL G, Justis ""(' ~ ¢ 0 K,
kurusuensis t. S. coliJorme 0) g[ tI:\ $'tI1!IHi, ~g[i" ¢ ::r /r ~ 1&1&£R. {I::::O:>1' r:, -t h:.f hSinemurian :>1'r:, Pliensbachian, Rhaetian:>1' r:, Sinemurian ? t.mJE~h¢o r$y,," '7 *~~g[i"¢ Katroma /j,li, ~t*, =¥ lJ ';;-7, r)t.-::r, :J j!iDR:$t.c C:>1' r:,¥IHs' ~h -C:to IJ, ggi¥§ B* ""('IiParahsuum simplum~~* (Lower Jurassic) 0)1:.$~~g[i"¢0 J:~-C, ~O)/j,~~/j,i"¢~li,{I::::o*O)~~)tt.l:t~i" ¢1:."Cm:J!"C~¢0 Parahsuum simplum ~~*1:.$li, ~hr:,O)g[tI:\li*:>1' r:,fUWfi"hlf, ~t*O) Pessagno r:, (1987) 0) Zones 04-01, Murchey (1984) 0) MH-I, :J)l*$0) Tikhomirova (1985) t;: J: ¢ Katroma(?) d, bicornus-Lithocampe sichotica Complex ~;:-th:.fh)tt(r;; L, .:to)1jO~lij;'t.ct Sinemurian ~M:>1' r:, Pliensbachian ~M~;::bt.:¢ mJE~
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Trans. Proc. Palaeont. Soc. Japan, N.S., No.151, pp. 564-569, 1 Fig., October 31, 1988

864. A TETHYAN BIVALVE, POSIDONOTIS DAINELLII,
FROM THE LOWER JURASSIC OF WEST JAPAN*

ITARU HAYAMI
Geological Institute, University of Tokyo, Tokyo 113

Abstract. A Monotis-like thin-shelled bivalve occurs from the Fontanelliceras
fontanellense Zone (upper Pliensbachian) of the Nishinakayama Formation in west Japan. This
bivalve, though formally undescribed, has been noticed by some foreign investigators from thestandpoint of biogeography, because such a bivalve often shows episodic occurrence and wide
geographic distribution. Recently, I observed some well-preserved materials of this species
stored in the Hiroshima Unviersity and the Mine City Museum of History and Folk Custom,
reaching a conclusion that it belongs to Posidonotis dainellii from the nearly contemporaneous
dark shales of Italy and Greece. The obliquely truncated auricles and radial costae of threeorders, which may be diagnostic of this species, are well recognized in the Japanese specimens.
The wide geographic distribution is probably related to the pseudoplanktonic mode of life. This
bivalve, as well as some ammonoids in the same fossil zone, is regarded as a noticeable element
indicating a marine faunal connection with the Mediterranean region at that time.

It has long been known since Matsumoto andOno (1947) that a Monotis-like thin-shelledbivalve occurs from the lower part of the
Nishinakayama Formation of the Toyora Group(upper Pliensbachian) in west Honshu, Japan.
Some specimens of this bivalve, though formallyremain undescribed, were illustrated by Hayami(1961, p1.14, fig.7) as Amonotis sp., and assigned
to Posidonotis by Hayami (1969) and Tanabe etal. (1982) and to Pectinula by Hallam (1977).
Tanabe et al. (1982) studied the litho- andbiofacies of this formation and pointed out thatthe sedimentary environment is comparable withthat of the "Posidonienschiefer" of west Germany. The dark shale bearing this bivalve is moreor less tuffaceous and especially well laminatedwith scarce bioturbation and fossils of definite
benthic organisms.
In Jurassic such Monotis-like bivalves episodically appeared several times; e.g. Diotis in thelower Lower Jurassic, Pectinula and Posidonotis

in the upper Pliensbachian-lower Toarcian, andAulacomyella in the Kimmeridgian. Their
opportunistic and exclusive occurrences as well
as extensive geographic distribution haveattracted the attention of many stratigraphersand paleoptologists from biostratigraphic, autoecologic alld biogeographic viewpoints (Losacco,
1942; Hayami, 1969; Hallam, 1977; Hillebrandt,
1981; Damborenea, 1987; etc.).
Recently I could observe several additional
well-preserved specimens of this bivalve in thecollections of the Hiroshima ,-dversity and theMine City Museum of History and Folk Custom.
Its taxonomic affinity and biogeographic significance also became much clearer through
Damborenea's (1987) comprehensive study ofrelated bivalves in South America and Europe.
On this occasion I systematically describe thischaracteristic bivalve and discuss several related
problems.

*Received June 9,1988; accepted September 1, 1988.
564

864.

Tethyan Bivalve, Posidonotis dainellii

Description of species? Family Posidoniidae Frech, 1909
Genus Posidonotis Losacco, 1942
Posidonotis dainellii Losacco
rigures 1A-lE

1942 Posidonotis Dainellii Losacco, p.3, text-fig. 2-1,
pl.1, figs.3-9.
1961 Amonotis sp.: Hayami, p.252, p1.14, fig.7.
1969 Posidonotis sp.: Hayami, p.379.
1977 Pectinula sp.: Hallam, p.64.
1982 Posidonotis sp.: Tanabe et at., p.56.
1987 Posidonotis dainellii Losacco ?: Damborenea,
p.194, text-figs.30a-d.

Type.:-Losacco (1942) failed to designate thetype specimen of this species, and therefore all
the illustrated specimens including two slabs withmoulds of numerous valves (pl.1, figs.4-9) are
regarded as syntypes.
Material:- The following description is mainly
based on a solitary well-preserved right valve(Fig.1A, 14.7mm long, ll.8mm high, preservedin the Geological and Mineralogical Institute,
Hiroshima University) collected by A. Ono fromthe Fontanelliceras fontanellense Zone of the
Nishinakayama Formation at Loc. Ty 98 (inMatsumoto and Ono, 1947) near the mouth of
Sakuraguchi Valley, south of Ishimachi, Toyoda
Town, Yamaguchi Prefecture. It is also supplemented by several slabs with numerous internaland external moulds preserved in the Hiroshima
University, University of Tokyo and the Mine
City Museum of History and Folk Custom
collected at the same locality and from the same
horizon at Loc.2 (in Tanabe et al., 1982), aquarry, south of Nishinakayama, Kikukawa
Town, the same prefecture.
Diagnosis:- Type species of Posidonotis
characterized by thin, subequivalve and prosoclinally oval shells with height much smaller
than length, straight postero-dorsal margin
much longer than antero-dorsal, umbonal angle
as large as 130 degrees, clearly demarcated,
flattened, obliquely truncated auricles andnotably cancellate sculpture which consists ofregular commarginal lamellae and more than 35

565

radial costae of three orders of prominence inadult stage.
Descriptive remarks.-The shell is preserved
only in a specimen (Fig.1A), in which radial
costae of three orders are clearly distinguishable.
The primary costae are about ten in number
and persistently strong especially in the middle
part. One secondary costa is regularly intercalated on each interspace of primary costae, andone tertiary costa appears between the primaryand secondary costae only in the late growthstage. So far as the present specimen is concerned, the anterior auricle is weakly rimmed
dorsally and more than three times larger thanthe posterior. Its growth lines do not indicate
any trace of byssal notch even in the young
stage.
All the other specimens are external andinternal moulds. Though the auricles are commonly incomplete and tertiary costae are often
difficult to observe even in large individuals,
every essential character of disk seems to be
identical between the two valves. There areseveral interesting slabs on which internal andexternal moulds of numerous individuals are
impressed (e.g. Figs.1D, IE). Some of them arearticulated but in many cases two valves are moreor less dislocated. The radial costae are generally
strong in the middle part of disk and somewhat
weakened towards the antero- and postero-dorsal
peripheries. Because of the extremely thin shell,
the hinge, ligament' and muscle structures are
difficult to observe in any available specimen.
Affinity:- Recently, Damborenea (1987)
pointed out that the Japanese specimens(Hayami, 1961, p1.14, fig.7) are close to Posidonotis dainellii from the upper Lower Jurassicof Sabina (Italy). Because all the original specimens of P. dainellii appear to be incomplete andrather poorly preserved, the species identity of
the Japanese specimens is not very decisive.
However, the general outline and size of disk aswell as the mode and number of radial costae
are so similar that specific distinction seems to beunnecessary. Furthermore, the gregarious specimens on several slabs from the lower Toarcian ofChionistra massif of Greece, which were pre-

566

Itaru H A YAMI

D

E
Figure 1. Posidonotis dain ellii Losacco , 1942
A: Righ t valve, x 2. Loc. T y 98 (Matsum oto and Ono, 1947), so uthwes t of Ishimachi, To yoda Town, Yamaguchi
Pref. ; Hiroshima Univ. co il. B: T he umbonal part of the same specimen, x 5. C: Right externa l mould , x 2. Loc.
the same ; Hiroshima Univ. co il. D: A slab wit h many external and int erna l mou ld s, x 2. Loc. near the mouth of
Sakuraguchi Valley, sout hwest of lshi mach i, Toyoda Town, Yamag uchi Pref. UMUT MM4 839 . E: A slab withmany ex ternal and internal mou lds with pla nt stems, x 1. Loc. 2 (Tanabe et al. , 1982), a quarry, south ofNishinakaya ma, Kikuk awa Town, Yamaguchi Prefecture; Mine City Museum of History and Folk Custom co lI.

864. Tethyan Bivalve, Posidonotis dainellii
viously collected by Renz (192 7) and illustrated
by Damborenea (1987, p.197, text-fig.30a-d) as
Posidonotis dainellii ?, are firmly identical withthe present specimens in every character of disk.
The Japanese specimens may be a little older
than the Greek ones, since the age of the former
has generally been regarded as late Pliensbachianbythecoexistenceof Fontanelliceras
fontanellense. Yet, the age discrepancy, if present, must be very slight, because such Toarciantype ammonites as Harpoceras okadai andDactylioceras helianthoides already appeared in
the same fossil zone (Hirano, 1973; Tanabe et al.
1982).
Hallam (1977) pointed out that the Japanese
specimens of this bivalve illustrated by Hayami(1961) may belong to the genus Pectinula, which
was proposed by Leanza (1943) on the basis of
P. cancellata Leanza, 1943, from the Middle Liasof Neuquen (Argentina). According to Damborenea's unpublished data distributed in the
Circum-Pacific Jurassic Field Conference at
Tsukuba, 1985, in Argentina this bivalve ranges
from the uppermost Pliensbachian to the lowest
Toarcian and therefore is almost contemporaneous with the Japanese specimens. As
was described by Damborenea (1987), this SouthAmerican species is clearly different from Posidono tis dainellii (including the present specimens) in the much taller and prosoclinal shell,smaller umbonal angle, larger auricles and fewer
radial costae, though the mode of cancellate
sculpturing is considerably similar.
Damborenea (1987) treated Pectinula as a
junior synonym of Posidonotis. Furthermore, sheregarded Posidonotis as belonging to the
Entoliidae mainly on the basis of the auricular
structure of Pectinula cancellata. According to
her restoration, Pectinula cancellata show elevated dorsal margins above the hinge axis in both
valves and the presence of byssal notch in theyoung stage. The restoration seems to be somewhat strange because such elevated dorsal margins are restricted to either valve (commonly
right valve) in the Entoliidae and other pectinacean families. Anyhow, the present specimens
of Posidonotis dainellii do not reveal any

567

Entolium-like appearance. The auricles, thoughincomplete in most specimens, are much smaller
than those of P. cancellata and show neither
elevated dorsal margins above the hinge line nor
the presence of byssal notch in the young stage.
The shape of the anterior auricles of both valvesappears to be rather similar to that of Halobia
and Paleozoic species of Posidonia. The disk also
does not remind me of that of an entoliid,
because the outline is too inequilateral for a
pectinacean and because the internal moulds
indicate the absence of auricular crura of
Entolium-type. I am, therefore, of the opinion
that the synonymous relation between Posidono tis and Pectinula as well as their familial
assignment is still debatable.
Autoecology:-Posidonotis dainellii often
occurs exclusively and gregariously in dark
shales, and very similar mode of fossil occurrenceis known in Italy, Greece and Japan. In the
Nishinakayama Formation many valves (partly
articulated) appear to form crowded colonies
around some plant stems like Zamites (Fig.lD,
IE), though their actual attachment by byssus
has not yet been ascertained. No fossils ofdefinite benthic organisms are found in association, and a considerably anaerobic bottom condition is indicated. It is indirectly suggested that
this bivalve was pseudo planktonic, as consideredby Hillebrandt (1981).
Biogeographic significance:-From the above
comparative study Posidonotis dainellii is concluded to be a widely distributed Tethyan bivalve
which shows a relatively short stratigraphic range
from the latest Pliensbachian to the early
Toarcian. This view is consistent with the predominance of Tethyan (especially Italian) elements in the ammonite fauna of the lower
Nishinakayama Formation (Arkell, 1956; Sato,
1962; Hirano, 1973). The Early Jurassic bivalve
faunas of west Japan are generally composed ofendemic species to eastern Asia (Hayami inpress). The unusually wide geographic distribution of this bivalve was probably related to its
pseudoplanktonic mode of life. Incidentally,
Pseudomytiloides matsumotoi from the superjacent Toarcian beds of the Nishinakayama

Itaru HAYAMI

568

Formation, which is surely pseudoplanktonic
according to Tanabe (1983), may be also an
extensively distributed species because it ishardly distinguishable from Pselldomytiloides
dlibiliS from the coeval argillaceous formations ofwestern Europe and various Tethyan regions (e.g.
Caucasus, Iran and Vietnam).
As was suggested by Damborenea (1987),
Pectinliia cancellata may be also a widely distributed species, since three nominal species described by Hyatt (1894) and Crickmay (1933)
from the Lower Jurassic of California are
possibly conspecific with the South American
species. Though the taxonomic kinship between
Posidonotis dainellii and Pectinliia cancellata is
still debatable, the two species seem tocharacterize distinct major marine faunal provinces in low and middle latitudinal regions atthat time, because their stratigraphic ranges andmodes of occurrence are quite similar.
Acknowledgements
I thank Emeritus Professor Akira Hase and Dr.
Yuji Okimura of the Hiroshima University and
Mr. Fumio Takahashi of Mine City Museum ofHistory and Folk Custom for the loan of several
interesting specimens, Dr. Kazushige Tanabe forhis cooperation in the field work, and also
Professor Koichiro Ichikawa of Osaka Universityof Technology and Dr. Alberto C. Riccardi ofMuseo de Ciencias Naturales (La Plata) for theirkind information about related bivalve.
References
Arkell, W. J. (1986): Jurassic Ceology of the World.
Oliver and Boyd, Edinburgh, 806pp.
Crick may, C. H. (1933): Some of Alpheus Hyatt's
unfigured types from the Jurassic of California.
Prof Paper, U. S. Ceo!. Surv., 175-B, p. 51-64,
pis. 14-18.
Damborenea, S. E. (1987): Early Jurassic Bivalvia ofArgentina. Part 2: Superfamilies Pteriacea,
Buchiacea and part of Pectinacea. Palaeontographica, Abt. A, Bd. 199, p. 1l3-216, pis. 1-14.
Hallam, A. (1977): Jurassic bivalve biogeography. Paleobiology, vol. 3, p. 58-73.
Hayami, I. (1961): On the Jurassic pelecypod faunas inJapan. J. Fac. Sci. Univ. Tokyo, sec. 2, vol. 13, p.
243-343, pI. 14.
--(1969): Notes' on Mesozoic "planktonic" bivalves.
J. Ceol. Soc. Japan, vol. 75, p. 375-385. (inJapanese).
in press. Geographic distribution of Jurassic bivalve
faunas in eastern Asia. In Pre-Jurassic Ceologic
Evolution of Eastern Continental Margin of Asia.
Hillebrandt, Von A. v. (1981): Kontinentalverschiebung
und die palaozoogeographischen Beziehungen dessudamerikanischen Lias. Ceo!. Rdsch., vol. 70, p.
570-582.
Hirano, H. (1973): Biostratigraphic study of the Jurassic
Toyora Group. Part III. Trans. Proc. Palaeont. Soc.
Japan, n. S., no. 90, p. 45-71, pis. 9-10.
Hyatt, A. (1894): Trias and Jura in the Western States.
Bull. Ceol. Soc. A'merica, vol. 5, p. 395-434.
Leanza, A. F. (1943): Pectinula, nuevo genero depelecipodos en el Lias de Neuquen. Notas Mus. La
Plata, n. s., Paleont. vol. 8, p. 241-249.
Losacco, U. (1942): Un nuevo genera aaleniano di
Aviculidae della Sabina. Riv. Ital. Paleont., vol. 48,
no. 1, p. 1-8, pI. 1.
Matsumoto, T. and Ono, A. (1947): A biostratigraphic
study of the Jurassic Toyora Group, with specialreference to ammonites. Sci Rept. Kyushu Univ.,
Geol., vol. 2, p. 20-33. (in Japanese)Renz, C. (1927): Die Verbreitung und Entwicklung desOberlias und Doggers im adriatisch-ionischen
Faziesgebiet von Hellas und Albanien. Verhandl.
Naturforsch. Ces. Basel, vol. 38, p. 482-515.
Sato, T. (1962): Etudes biostratigraphiques desammonites du jurassique du Japon. Mem Soc.
geol. France, n. S., memo no. 94, p. 1-122, pis.
1-10.
Tanabe, K. (1983): Mode of life of an inoceramidbivalve from the Lower Jurassic of west Japan. N.
Jb. Ceo!. Palaont. Mh., 1983, p. 419-428.
- - , Inazumi, A., Ohtsuka, Y., Katsuta, T. andTamahama, K. (1982): Litho- and biofacies andchemical composition of the Lower Jurassic
Nishinakayama Formation (Toyora Group) in west
Japan. Mem. Ehime Univ., Sci., ser. D, vol. 9, p.
47-62. (in Japanese)864.

Tethyan Bivalve, Posidol1otis dainellii

569g§ E! i:O)T$;; "'- '7 *~O) T 7-.A *=(l(J'l. Posidonotis dainellii : i:1+I[!§iilfij$ 0) ~i1Ii ~ll¥[!§ q,

v:. Monotis ~={l(J'l. (lE~v:.
::. .;fV£ -c'v:'Wjj.O)liJf9'e~;b, G t r-± § ~ h -n ,t-:o ~@], $.Jiih*,*to J: lf~iFmmM:5:~~~~!llv:.*~~h -C~'0*:fHHfO)~i::z-~§i Ltdi!i,*, ::. o)~~i-1 !l~ - • 4"0 ~ :/-vO)vuf[lijMO)~t3~:E;b'G:9;aGh0 Posidonotis O)m~~p. dainelliiV:.v~v;f!it~

i1I~O) Fontanelliceras fontanellense fIl' (7' ~ /'.A /( 4'-7 /'12tM)~i*8C~) ;b~~l±l-t" 0::' C: ~i,K[lij~~h,~*~OO!it~~~ki:~O)~~$~*OO.~O)~E~~~G;b'C:~~ko i:~0)$.
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fIl';b, G~-t" 07 /'1:- j- -1 )0 ll¥ U:l;v:., jjEq,W::!JOO C: O)1:¥J.JjjE:£!I[J:O)Mjf:z-~-t"~~ C: L -Cr-± § ~

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Trans. Proc. Palaeont. Soc. Japan, N.S., No. 151, pp. 570-581, 15 Figs., October 31,1988

865. SOME INOCERAMIDS (BIVALVIA) FROM THE
CENOMANIAN (CRETACEOUS) OF JAPAN - IV
AN INTERESTING NEW SPECIES FROM HOKKAIDO*TATSURO MATSUMOTO
c/o Department of Geology, Kyushu University 33, fukuoka 812

and
KEISAKU TANAKA
Nakayama, 3-62-10, 1200-109, Hachioji, Tokyo 192-03

Abstract A specimen obtained by K. T. from his Member Tc (=IIc of T. M.), ie. themiddle part of the Mikasa formation in the Ikushumbets Valley, was labelled as Inoceramus cf.
etheridgei Woods and is hold in the Geological Museum of the Geological Survey of Japan. Thisis restudied by us together with other relevant specimens from the Upper Cenomanian strata in
the Ikushumbets and Oyubari areas, central Hokkaido. They represent a new species which isallied to 1. scalprum Biihn (=1. etheridgei Woods, currently included in 1. virgatus SchlUter as avariety or a subsp. by some authors), but characterized by regular concentric ribs in addition tofine concentric lirae. This species resembles 1. atlanticus (Heinz) but is distinguished by adissimilar outline of the shell caused by its anteriorly concave growth axis instead of the nearlystraight to weakly convex one of that species. We interpret that this species may have evolved
from the scalprum-like form of the variable species 1. virgatus. with development of distinct
ribs. There seems to be a reduction in size at higher levels than the type locality. Some of thespecimens previously reported under 1. tenuistriatus Nagao et Matsumoto from the Cenomanianstrata in various regions of the world may be preferably transferred to this species.

Introduction

him, because it did give him a hint to solve an
entangled problem (to be discussed below) inwhich palaeontologists specializing in the inocerarnids have been involved.
We have investigated this particular specimen
together with other relevant ones, mostly thosecollected by T. M., sometimes with his colleagues, through field works in the Oyubariarea (adjacent to the south of the Ikushumbetsarea), now kept in the Geological Collections,
Kyushu University (GK) and partly those fromthe Ikushumbets area, deposited in the Instituteof Geology and Palaeontology, Tohoku University. Sendai (IGPS). As a result a new
species is established in this paper, giving remarks

One of us (Tanaka, 1985) listed some fossil
specimens from the Cretaceous System of Japan,
hold in the Geological Museum of the Geological
Survey of Japan (GSJ), Tsukuba, which heobtained, sometimes with coworkers, during thefield works to prepare geological maps on scale
1: 50,000 in various areas of Japan. The other ofus (T. M.) has recently visited the Museum tolook at several specimens selected from the list.
One of them, GSJ. F8275 from Ikushumbets,
central Hokkaido, listed as Inoceramus cf.
etheridgei Woods, was particularly interesting to*Received March 30, 1988; accepted July 10, 1988.
570

865. Cenomanian Inoceramids from Japan - IVon its implications in the taxonomy of the
Inoceramidae.
This paper is added as Part IV of the serial
papers under the above indicated major title,
which was intended at the beginning to consist of
three parts (Matsumoto and Noda, 1986, p. 410).
Systematic description
Genus Inoceramus Sowerby, 1814

Type species:-Inoceramus cuvierii Sowerby,
1814.
Remarks:-In this paper the genus Inoceramus
is used in a broad sense as in Matsumoto et al.
(1987, p. 148). As to the technical terms andtheir abbreviations we follow those in Matsumoto and Noda (1986, P. 410).
Inoceramus nodai sp. nov.
f'igures 1-3,5-13

1966 Inoceramus tenuistriatus (?) Nagao et Matsumoto; Pergament, p. 47, pI. 13, figs. 2-4; pI. 14,
figs. 2-4.
? 1977 Inoceramus tenuistriatus ? Nagao and Matsumoto; Kauffman and Powell, p. 67, pI. 2, fig. 5;
pI. 3, figs. 7,9,10.
1982 Inoceramus tenuistriatus Nagao & Matsumoto;Keller, p. 62, pI. 1, figs. 3a, b.
1985 Inoceramus cf. etheridgei Woods; Tanaka, p. 57.

Material:-Holotype, GSJ, F8275A (Fig. 1),
BV, in a calcareous nodule collected by K.
Tanaka at loco Iw32 (=T. M.'s loco Ikl043) fromthe siltstone in the main part of K. T.'s Member
Tc (=T. M.'s Member IIc), Middle Member of theMikasa Formation exposed across the mainstream of the River lkushumbets, central Hokkaido.
Paratypes, 36 specimens enumerated asfollows: (1) GSJ. F8275B, RV, partly croppingout from the same nodule as the holotype; (2-4)
small, probably juveniles, IGPS. 86187B (Fig. 2),
C (Fig. 3) (both RV) and D (LV) in a calcareous
nodule of sandy siltstone, Member lIc of theMikasa Formation on the River Ikushumbets,
without record of collector; (5,6) GK. H8259A,
B (Fig. 5) (RV and LV) in a nodule collected by

571

T. Matsumoto with Y. Kawashita from the
mudstone at loco Y5111e5;(7-12)GK.H8260A(Fig. 6) B, C, D (these four LV) and E, F (RV)
collected by T. M. at loco Y5111e4 from thesame bed as (5, 6), i.e. in the uppermost part ofthe probable extension of Member lIm (Matsumoto, 1942, p. 230), Taki-no-sawa route, Oyubari area, central Hokkaido; (13) GK. H8269A(RV) (Fig. 7) and (14, 15) GK. H8270A (RV)
and B (RV) from loco Y5111; (16, 17) GK.
H8272A (LV) (Fig. 8) and B (RV) from loco
Y5112; (18-24) GK. H8273A (Fig. 13), B (Fig.
10), D, F (Fig. 12), G (Fig. 9) (all these five LV)
and C (RV) (Fig. 11) and H (RV) from loco
Y5113; (25-29) GK. H8274A, B (LV) and C, D,
E (RV) from loco Y5113; (30-36) GK. H8275A,
B (RV) and C, D, E, F, G (LV) from loco Y51l1;
13-36 developed or separated by T. M. from thecalcareous nodules obtained through the fieldwork (in 1969) by T. M. and H. Okada fromsandy siltstone beds in the unit of alternating
sandstone and siltstone, probable extension ofMember lIm.
The above enumerated specimens are mostlyinternal moulds or composite internal moulds,
with partly attached inner shell layer. Externalmoulds are available for GK. H8259, GK. H8269
and GK. H8272B.
Etymology:-This species is dedicated to Dr.
Masayuki Noda who has contributed much to thetaxonomy and biostratigraphy of the Inoceramidae.
Diagnosis:-Shell medium to small sized, subequivalve and inequilateral. Valves gently convex
in general, but for moderately convex umbonal
part. Beak at the anterior end, small, pointed andnot much exceeding the hinge line even in theleft valve. Anterior hinge angle (=apical angle, a)
95° to 110°. Axis of growth nearly straight inyoung shell and gradually curved forward withgrowth, forming anteriorly concave curvature.
Anterior margin nearly straight or gently concave
and abruptly bent at the antero-ventral edge tothe asymmetrically sub circular ventral margin,
which passes to the longly arcuate posterior
margin. Hinge line of moderate length (s/1 =2/3
in the holotype), forming obtuse angle (125°_

572

Tatsuro M A TS UMOTO and K eisaku T ANA KA140°) with the posterior margin. Postero-dorsal
wing-like part narrow, to which the main part ofthe disk gradually inclines. The maximum inflation of valve immediately in front of thegrowth-axis; anterior side nearly vertical or overhanging.
Surface of shell ornamented with fine anddense concentric lirae and fairly regularconcentric ribs of low to moderate intensity.
Concentric rings may be discernible on some partof the internal mould, corresponding to the
sharper lirae on the shell surface .
Dimensions:-See Table l.
Observation: - The holotype consists of both

865.

Cenomanianinoceramids li'Oln Japan - iV

573

Table 1. Measurements of 1. nodai on selected specimens
Specimen

V

GSJ. F8275
GSJ. F8275
GSJ. F8275
GSJ. F8275
IGPS.86187B
IGPS.86187C
GK. H8259A
GK. H8269A
GK . H8272A

R 81.2
R 61.0R 34.3
R 18 .3
R 16 .9
R 9.0
R 17 .3
R 27.8

GK. H82 73A
GK. H8273B
GK. H8273C
GK. H8273Gh

L 22 .0
L 20.0L 21.0

R 15 .7
L 20 .0

1

I

II/ h

66.2
51.2
30.7
17 .1
13.2
8.0
14.3
21.8
19.6
17 .6

.82
.84
.85
.93
.80
.89
.83
.78
.89
.88

18 .0
14.0
17.4

.86
.89
.87

H 1
86 .0
63.0
39.0
21.2
17.2
10 .7
17.8
29.6
24 .0
21.5
22.4
17.5
22.0

L
69.8
52.2
33.2
19 .0
13 .6
8.8
15 .2
23.2
20.8
19.5
18 .8
14.7
18.7

I L/ H
.81
.83
.85
.90
.79
.82
.85
.78
.87
.90
.84
.84
.85

b l b/ h

s

I s/l

a

1 1
f3

T

j i5

22.0

.27

43.0

.65

100°

-

137° 63°

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

4.1
2.2
4.8
6.4
6.2
6.2
6.8
5.0
6.6

.25
.24
.28
.23
.28

9 .3
5 .6
10 .5
14.0
13.0

.70
.70
.73
.64
.66

.31
.32
.32
.33

-

-

13 .2
9.6
12.4

.73
.68
.71

105° 105° 110° 103° 97° 80°
115° 75°
113° 75°
100° 95° 80°

-

65°
50°
55°
60°
50°
55°
60 °
62°
125° 58°

125 °
130°
100°
130°
125°

Figure 1. Inoceramus nodai sp. nov.
.
Ikushumbets, lo wer part of Member Tc
Ho I0 t ype, GS J . F8275A (BV) , from loco Iw32 (= Ik1043) of the RIver
. .
f
GSJ
(= Ilc), Mikasa Formation (K. Tanaka Coll.). A: lateral view of RV , wll h a ventral portion 0 a paratype,.
f8275B at the bottom; B: anterior view of RV and half exposed LV , with a postenor vIew ofGSJ. F8275B at
the bottom; C: dorsal view of BV (umb o of LV defi cient) ; 0: RV in particular VJew , show1l1g ItS umbonal partbetter than A; all in natural size (x 1).
Photos (figs. 1- 15) by courtesy of Dr. Masayuki Noda.

574

TatsuroMATSUMOTO and Keisaku TANAKA

valves, 'of which the left valve is deficient inlacking the umbonal part and only half exposed.
We had to stop triming the concealed posterior
half; otherwise the better preserved right valve
would be destroyed, because the specimen is too
fragile. The right valve is a composite internalmould for the major part and the inner shelllayer is attached to the posterodorsal part andsome other portions, where fine concentric lirae
are discernible in addition to the regular ribs. The
ribs are low but rather sharp at their summit. So
far as the visible part is concerned, the differencein the convexity or breadth (b) of the valve isslight between the left and right valves of theholotype.
Another right valve (paratype 1), which crops
out from the same nodule as the holotype, has
somewhat coarser and rather rounded ribs ascompared with those of the holotype, although
the difference is by no means great.
Other paratypes (2 to 36), which came fromcomparatively higher parts of the Upper Cenomanian, are smaller than the holotype. Some ofthem may be juveniles. The largest of them is 35
mm in H and may be adult. Others may be atleast middle-aged (see remarks below). Thosefrom locs. Y5111, Y5112 and Y5113 are often
embedded in school, but left and right valves aremostly separated. As far as the well preserved
specimens are concerned, the beak of the left
valve is slightly projected beyond the hinge line.
Of the paratypes 2 to 36, the figured 12
specimens are better preserved in showing boththe shell-form and ornamentation. Even in theunillustrated specimens with deficient outline, theornament may be well shown. In the normalcases of this small form, the ribs are distinct andrather sharply headed (e.g. GK. H8259A; GK.
H8273A, B, C; GK. H8274A, B). In the lessconvex valves, which may be originally so insome cases but due to secondary compression inother cases, the major ribs are low, but fine anddense, concentric lirae may be well shown (e.g.
GK. H8269A, B; GK. H8272A, B; GK. H8275A,
B, C,D).
The major ribs are normally regular in thegradual increase in strength and interval, but theirregularity by bifurcation or intercalation may
sometimes occur. The ribs begin to develop
distinctly at the stage with H=15 mm in theholotype. In the smaller paratypes from locs.
Y5111-Y5113, the ribs begin to be discernible
at H=8 to 11 mm and in the case of very small
IGPS. 86187C and B, probably from the higher
bed than the holotype in the Ikushumbets route,there are 4 and 6 ribs at their H=lO mm and 15
mm respectively. Generally the intervals of theribs are narrower and the ribs look to be more
crowded in many, if not all, of the smallparatypes as compared with those of the holotype. The above facts suggest that there isvariation in size and that many of the small
specimens from the higher part of the Upper
Cenomanian may be already middle-aged and thelargest one (H=35 mm) may be adult.
There is also some extent of variation inshell-form. For example, GK. H8269A and IGPS.
86187B represent a comparatively higher form
with a smaller ratio of L/H or llh than that of thenormal form. They are contained in the same
nodule as some examples of the normal form andthe difference in the value of L/H or llh is not
great (see Table 1). The convexity of the valvesvaries to some extent. The ratio blh, which may
reflect the convexity, ranges from 0.24 to 0.33 in
the measured specimens.
Comparison and discussion:-With respect tothe regular concentric ribs combined with fineand dense concentric lirae, this species is similar
to Inoceramus atlanticus (Heinz). The latter
species was proposed by Heinz (1936, p. 96),
under the genus Camptoceramus Heinz, 1932
(nom. nud.) for the two illustrated specimens ofI crippsi var. reachensis in Woods (1911, p. 278,
pl. 48, fig. 5 and pl. 49, fig. 1), from the Zone ofHolaster subglobosus (Lower Chalk, Cenomanian) of England. Later Woods' pl. 48, fig. 5
was designated as the lectotype by Pergament(1966, p. 58) prior to Keller's (1982, p. 58) toolate designation of the other specimen.
Incidentally, Kauffman (1978, p. iv. 4) called
Woods' pl. 48, fig. 5 I (Mytiloides ?) reachensis
reachensis Etheridge and Woods' pl. 49, fig. 1 I(Mytiloides ?) reachensis n. subsp. A, without

865.

Cenomanian Inoceramids jj·om Japan -IV

glVlng comments on 1. at/anticus (Heinz), andmentioned further that the former occurs in the
Neostringoceras carcitanense Zone and the latterin the Mantelliceras saxbii Zone. On examining
the above specimens in the British Museum(Natural History) and also their plaster casts in
Kyushu University (GK. H9581 and GK.

575

H9582) , one of us (T. M.) considered that they
could possibly be referred to the genus
Mytiloides, because of the evenly very fine anddense concentric lirae on the very thin shell in
addition to regular major ribs. In fact Matsumot.o(1959, p. 85) and Matsumoto and Noda (1975)
mentioned as a working hypothesis that 1.

Figures 2,3. Inoceramus nodai sp. nov.
Para types, IGPS . 86187B (2) and C (3) (RY, probably juveniles), from the Ikushumb e ts. 2, 3: x 1; 2 x , 3 x:
enlarged, x 2.
Figure 4. Tarrantoceras aff. stal1tol1i Stephenson.
IGPS. 86187 A, contained with Band C in one and the same nod ule, Memb er IIc (presumably its uppermost
part), Mikasa formation . Right (a) and left (b) lateral, ear lier (e) and later (d) ventral views of the outer whorl ;external mould of inner whorls (e), x 1.

TatsuroMATSUMOTO and Keisaku TANAKA

576

reachensis (of Woods) could belong to theancestral root stock from which Mytiloides
labiatus (Schlotheim) may have offshooted. Anyhow, the above view is a suggestion for thequestion to what genus belongs the species
proposed in this paper. We should, however,reserve the final answer until reliable evidence isobtained.
Aside from the question of generic assignment, we should mention here as to the validityof L atlanticus. One of us (T. M.) once (in 1954)
studied the syntypes of Inoceramus latus var.
reachensis Etheridge, 1881 in the Sedgwick
Museum, Cambridge. They are SM. B7173,
B7174 and B7175 from the Totternhoe Stone of
Burwell, Cambridgeshire, and more or lesssecondarily deformed or compressed. One ofthem, SM. B7173, figured by Etheridge (1881, p.
142, pI. 1, fig. 3) was designated by Woods(1911, p. 278) as the type, i e. lectotype. It ismuch more elongated along the more oblique
growth-axis than the above mentioned specimensof Woods (see Table 2). Therefore, the separationof L atlanticus from L reachensis (s. str.) can bejustified. The two nominal species are, however,so similar in showing evenly dense and very fineconcentric lirae on the very thin shell in addition
to regular major ribs that sub specific distinction
may be preferable. Without inspecting more
specimens from successive levels, it is difficult todraw a final conclusion. In this paper, wetentatively use the specific name L atlanticus on
the ground of the above difference in shell form.
L atlanticus has been reported also from the
Cenomanian of France (Sornay, 1978, pI. 1, fig.
4), Germany (Keller, 1982, p. 57, pI. 1, fig. 6)

and probably Kamchatka (Pergament, 1966, p.
58, pI. 5, fig. 3 with cf.). In every figured
example of L atlanticus, the axis of growth is atrust nearly straight and then slowly curved
toward the posterior, forming a gently convex
curvature to the anterior.
In this new species, the axis of growth is at
first nearly straight but soon curved toward theanterior, forming distinctly an anteriorly concaveline. This character is constantly kept in every
specimen examined. On account of thisdifference, the outline of the shell is alsodissimilar between the two species.
The fine and dense concentric lirae and thegeneral shell-form as well as the stratigraphic
occurrences suggest that the two species may
have diverged from a variable species L virgatus
SchlUter (recently redefined by Matsumoto et aI.,
1987), acquiring the better developed major
concentric ribs.
Should the sub specific definition by Keller(1982) be maintained, then the origin of L nodai
sp. nov. would be ascribed to L virgatus scalprum
Bohm and that of L atlanticus could be so to L
virgatus virgatus SchlUter. Matsumoto et al.
(1987) have denied the sub specific separation
because of the presence of forms with mixed
characters and the coexistence of various forms
in the same province of the same geological age.
However, in some late age of the Cenomanian,
the divergence into two (or more) species myhave taken place. Anyhow, the above interpretation would be disharmonious with the aforementioned suggestion to refer L atlanticus (=Lreachensis of Woods) to Mytiloides, unless L
virgatus is referable to Mytiloides.

Table 2. Measurements of the discussed species on selected specimens.
SpecimenV(1) Dibley Coli.
(2) BM. Ll0378(3) SM. B7173(4) USNM. 169393

R -42
R 70
R 74
R 10.5

(1)
(3)

h

II

II/h

H I L

45 -42 .93
68
61 .8990
60 .6711.1
8.3 .89

40 .9563 .9069 .93
7.9 .75

l. at/anticus, lectotype;l. reachensis, lectotype;

I L/H

(2)
(4)

S

Is/I Is/L-22 .55
32 .51
32 .46
4.5 .57

l. at/anticus, paralectotype;l. aff. ginterensis

.52
.52
.53
.54

a

l~

135°
120° 120°93° 140°95° 124°1 0
65° - 70°
60° - 65°48°
63° - 78°865. Cenomanian Inoceramids from Japan - IV
I nodai sp. nov. is somewhat similar to I
tenuistriatus Nagao et Matsumoto, 1939. We
should recall here that Matsumoto (1959, p. 84)
once mentioned that I tenuistriatus is somewhat
allied to I etheridgei Woods, 1911 (=l virgatus
scalprum Bohm, 1915) but is evidently later(Turonian) ·in age. Kauffman (1977, p. 178;
1978, p. iv.4-5) also regarded I tenuistriatus asa member of "the I etheridgei lineage."
I tenuistriatus was established on several
syntypes from the celebrated exposures (locs.
Ik2012-2014) of the Upper Turonian strata on
the River Pombets (see Matsumoto, 1984, fig. 3).
It was defined fairly clearly and is now being
restudied by Noda (1988) in parallel with thiswork. That species is constantly small andsomewhat inequivalve, with more convex
umbonal part which is steeply inclined to thepostero-dorsal wing-like part. Its axis of growth isstraight throughout, without showing such acurvature as that of I nodai. It has fine anddense concentric lirae as those of this species but
is devoid of such regular concentric ribs as thoseof I nodai and I at/anticus. Only weak concentric subcostae or undulations may occur
irregularly in some specimens of I tenuistriatus.
Those forms which have been described orreported under I tenuistriatus, with or without aquery, from the Cenomanian of various regions
outside Japan by Pergament (1966), Kauffman
and Powell (1977), Kauffman (1978, withoutfig.) and Keller (1982) (see above list ofsynonyms) are not referred to the named species.
We are inclined to transfer them to I nodai on
the basis of their described and illustrated
characters, although the final conclusion should
be deferred until we examine the actual specimens or at least their replicas.
Although I tenuistriatus and I nodai sp. nov.
are distinguished, the two species might be
genetically related. If the characters in the early
growth-stage of I nodai were retained andextended to a small-sized adult of the descendant, I tenuistriatus could be formed. To
verify this hypothetical presumption of paedomorphosis, it is eagerly required to study thematerial from the lower part of the Turonian.

577

In this connexion it is interesting to see thatthe investigated specimens of I nodai from theupper part of the Upper Cenomanian are small ascompared with the typical form (holotype andothers) from the lower part of the same substage
in the sequence of Hokkaido.
A comparatively higher form among the population of I nodai from higher levels, as represented by IGPS. 86187B (Fig. 2) and GK.
H8269A (Fig. 7), is noteworthy in its similarity
to a peculiar form said by Kauffman and Powell(1977, pI. 1, fig. 1) as "a young I ginterensis
Pergament showing abnormally close, regularjuvenile rugae", from the Hartland Member ofOklahoma. That North American form is indeed
similar to I ginterensis in the outline of shell, butsuch regular ribs do not appear on the youngshell of typical I ginterensis. It should be called
I aff. ginterensis (Table 2-4) or could be called
I aff. nodaL
We should mention here that there is anotherpeculiar form represented by GK. H8269B (Fig.
14) and GK. H8271A (Fig. 15), which wereintermingled with some specimens of I nodaL It
differs from the latter species in its obliquelyelongated outline with straight growth-axis,
smaller apical angle and narrowly raised, regularribs of stronger curvature. Although the two
specimens are immature or middle-aged, they
resemble the holotype and other examples of
Inoceramus schoendorfi (HeinZ) from the Upper
Cenomanian of Germany (near Hanover) and
Denmark and Upper and Middle Cenomanian ofFrance (see Sornay, 1980, p. 2, pI. 1, figs. 1-5).
I schoendorfi may be allied to but is clearly
distinct from I nodai by the above characteristics. We call the above mentioned form from
Hokkaido tentatively I cf. schoendorfL
Occurrence:-The nodule, which contains theholotype and the para type 1, was obtained by K.
T. from his loco Iw32, i.e. T. M.'s loco Ikl043. It
is on the main course of the River Ikushumbets,
about 530 m downstream from the Katsurazawa
dam and slightly upstream from the entrance of asmall branch stream called the Suido-no-sawa.
The nodule was in dark grey siltstone which
belongs to the lower part of the Middle Member

578

Tatsuro MATSUMOTO and Keisaku TANAKAof the Mikasa Formation, marked Tc by K. T. (inMatsuno et at., 1964, p. 28) or IIc by T. M. For
the location on the route map and stratigraphic

section see figs. 2 and 4 in Matsumoto (1965)
and for the general stratigraphy of the lkushumbets Valley see Matsumoto et al. (1978, p.

Figures 5-13. Inoceramus nodai sp. nov. Paratypes.
5: GK. H8259A (RV) and B (LV. oblique view of anterolateral part) from loc . .Y5111e5 (T. Matsumoto Call.),x 1. 5 x: Ditto, enlarged, x 2.6: GK. H8260A (LV) from lac. Y5111e4 (T. M. Coll.) , x 1.5 . 7: GK. H8269A(RV) from lac. Y5111 (T. M. & H. Okada Call.), x 1.5 . 8: GK. H8272A (LV) from lac. Y5112 (T. M. & H. O.
Call.) , x 1.5. 8p: Ditto, posterior view, x 1.5. 9, 9a: GK. H8273G (LV); 10, lOa: GK. H8273B (LV) ; 11: GK.
H8273C (RV); 12, 12a: GK. H8273F (LV); 13: GK. H8273A (LV) , these five in the same nodule from lac.
Y8213 (T. M. & H. O. Call.); 9a, lOa and l2a are anterior views of 9, 10 and 12; all x 1.5 . 5-13 on the
Taki-no-sawa rout e, extension of Member llm (of the Shiyubari, Matsumoto , 1942), Oyubari area.

.865.

Cenomanian Inoceramids from Japan - IV

14
Figures 14,15. Inoceramus cf. schoendorfi (Heinz).
14: GK. H8269B (RY), probably juvenile, containedwith GK. H8269A (rig. 7) in the same nodule. IS: GK.
H8271A (RY), probably middle aged, contained with
GK . H8270A, B (1. nodai, no fig.) in one and the same

nodule. Both from loco Y5111 , Taki-no-sawa route,extension of Member lIm, Oyubari area (T. M. & H. O.
Coll.). x 1.5 .

xxxiii.3-5, figs. 6-8). From the main part ofMember IIc occur Eucalycoceras pentagonum(Jukes-Browne) and Calycoceras cf. naviculare(Mantell) (see Matsumoto, 1975), indicating thelower part of the Upper Cenomanian.
IGPS. 86187B-D, i e. paratypes 3-5, are in adark grey calcareous nodule from Member IIc of
the Ikushumbets Valley. The nodule contains
Tarrantoceras aff. stantoni Stephenson (IGPS.
86187 A) (Fig. 4) and numerous, drifted vegetable fragments, suggesting its derivation fromthe uppermost part of Member IIc, i e. the Zoneof Euomphaloceras (Kanabiceras) septemseriatum, next higher zone than the Pentagonum
Zone.
Numerous specimens from locs. Y5111 , 5112
and 5113 are in calcareous nodules contained in
mudstone layers of a member of alternating
sandstone and shale in the section along thestream Taki-no-sawa, Oyubari area. This member
corresponds to Member lIm (Matsumoto, 1942)of the Shiyubari area, adjacent to the northeastof the Oyubari area. It is referred to the Upper
Cenomanian because it contains Damesites cf.
laticarinatus Saito et Matsumoto and Marshallites
compressus Matsumoto and because it is immediately below the bed with Pachydesmoceras
kossmati Matsumoto and Pseudaspidoceras

579

jlexuosum Powell, the latter of which is an index
of the Basal Turonian (Kennedy et al., 1987).
This bed is followed above by a unit of mudstone
characterized by Mytiloides mytiloides (Mantell)in the main part with intercalated key beds oftuff and tuffite. This unit certainly corresponds
to Member lIn of the Shiyubari area (Matsumoto, 1942) and referred to the Lower
Turonian.
This new species has been established on thematerial from the Upper Cenomanian of thelkushumbets and Oyubari sections, but its true
range has yet to be worked out by further
investigations of other sections.
Probable examples of this species outside
Japan illustrated under 1. tenuistriatus (with orwithout a query) are from the Zone of Dunveganoceras albertense and that of Sciponoceras
gracile-E. (Kanabiceras) septemseriatum in theUpper Cenomanian of Oklahoma (Kauffman etal. , 1977), also the Middle Cenomanian of the
Sack-Mulde, Germany (Keller, 1982) and theUpper Cenomanian of the Koryak-Kamchatka
region (Pergament, 1966).
Acknowledgements
We wish to thank Dr. Nobukazu Kanbe and
Dr. Toru Sakamoto, the former and the present
Keepers of the Museum, Geological Survey ofJapan, and Professor Tamio Kotaka of Tohoku
University for their generosities to let us study
the GSJ and IGPS specimens on loan. Thanks areextended to Dr. Masayuki Noda for his friendly
help in taking photographs and for the fruitful
discussions and also to Dr. Yoshio Sato of GSJ
for his assistance in various ways . One of us (T.
M.) greatly appreciate the kindness of Drs.
Gregorio Lopez and S.R.A. Kelly for supply of a
Spanish paper and Etheridge's respectively, thehelp of Drs. Hakuyu Okada, again Dr. M. Noda,
Mr. Yoshitaro Kawashita and Ms. Kikuye Kato in
his frequent field works in the Oyubari area ,and the assistance of Miss Yoshimi Tanigawa in
preparing the typescript.

580

Tatsuro MATSUMOTO and Keisaku TANAKA

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Bohm, J. (1915): Zusammenstellung der Inoceramen
der Kreideformation (Nachtrag). Jb. kgl. preuss.
geol. Landesanst., vol. 35, no. 3 (for 1914), p.
595-599.
Etheridge, R. (1881): Palaeontology. In Penning, W. H.
and A. r. Jukes-Browne: Geology of the neighbourhood of Cambridge. Mem Ceol. Surv. Englandand Wales, p. 133-144,3 pis.
Heinz, R. (1932): Aus der neuen Systematik derInoceramen. (Beitrage zur Kenntnis der Inoceramen XVI). Mittei/. Mineral.-Ceol. Staatinst. Hamburg, vol. 13, p. 1-26.
--(1936): Inoceramidos de Alicante, Valencia yBaleares. (Contribuciones al conocimiento de losInoceramidos XV). Bol. Soc. Esp. Hist. Nat., vol.
36, no. 2, p. 91-99, pI. 13.
Kauffman, E. G. (1977): Systematic, biostratigraphic
and biogeographic relationships between Middle
Cretaceous Euramerican and North Pacific Inoceramidae. In Matsumoto, T. (Organ.): MidCretaceous Events - Hokkaido Symposium, 1976-. Palaeont. Soc. Japan, Spec. Pap., no. 21, p.
169 -212.
--(1978): British Middle Cretaceous inoceramid biostratigraphy. In Reyment, R. A. and G. Thomel(Organ.): Mid-Cretaceous Events - Uppsala 1975
- Nice 1976. Ann. Mus. d'Hist. Nat. Nice, vol. 4(for 1976), p. ivol-ivo12.
- - , D. C. Hattin and J. D. Powell (1977): Stratigraphic, paleontologic and paleoenvironmental
analysis of the Upper Cretaceous rocks of
Cimarron County, northwestern Oklahoma. Mem
Ceol. Soc. Amer., vol. 149, 150 pp., 12 pis.
and J. D. Powell (1977): Paleontology. In Kauffman et al., (1977): Ditto. Ibid., vol. 149, p.
47-150, pis. 1-12.
Keller, S. (1982): Die Oberkreide der Sack-Mulde bei
Alfeld (Cenoman-Unter-Coniac). Lithologie, Biostratigraphic und Inoceramen. Ceol. lb. A 64, p.
3-171 (incl. pis. 1-8).
Kennedy, W. J., C. W. Wright and J. M. Hancock(1987): Basal Turonian ammonites of West Texas.
Palaeontology, vol. 30, no. 1, p. 27 -74, (incl. pis.
1-10).
Matsumoto, T. (1942): rundamentals in the Cretaceous
stratigraphy of Japan. Part I. Mem Fac. Sci.,
Kyushu Imp. Univ., Ser. D (Ceol.), vol. 1, no. 3, p.
130-280, pis. 5-19.
- - (1959): Zonation of the Upper Cretaceous in
Japan. Mem Fac. Sci Kyushu Univ., Ser. D(Ceol.), vol. 9, no. 1, p. 55 -93, pis. 6 -11.
--(1965): A monograph of the Collignoniceratidae
from Hokkaido. Part I. Ibid., vol. 16, no. i, p.
1-80, pis. 1-18.

- - (1975):
Additional
acanthoceratids
from
Hokkaido. Ibid., vol. 22, no. 2, p. 99-163, pis.
11-23.
--(1984):
The
so-called
Turonian-Coniacianboundary in Japan. Bull. Ceol. Soc. Denmark, vol.
33, p.171-181.
- - , A. Asai and H. Hirano (1987): Some innoceramids (Bivalvia) from the Cenomanian(Cretaceous) of Japan-II. Three species from
Hokkaido, well known abroad but hitherto undescribed in Japan. Trnas. Proc. Palaeont. Soc. Japan,
N. S. no. 147, p. 146-164,8 figs.
- - , - - , - - and M. Noda (1988): Ditto - III.
Three species occurring commonly in the Northwest Pacific region. Ibid. no. 150, p. 378-395,9
figs.
- - and M. Noda (1975): Notes on Inoceramus labiatus(Cretaceous Bivalvia) from Hokkaido. Ibid., no.
100, p. 188-208, pI. 18.
- - and - - (1986): Some inoceramids (Bivalvia)
from the Cenomanian (Cretaceous) of Japan-I.
New or little known four species from Hokkaido
and Kyushu. Ibid., no. 143, p. 409-421, pis.
81-85.
- - , H. Okada, H. Hirano and K. Tanabe (1978):Mid-Cretaceous zonation in Japan-I. MidCretaceous
biostratigraphic
successioninHokkaido. In Reyment, R. A. and G. Thomel(Organ.): Mid-Cretaceous Events
Uppsala1975-Nice 1976 -. Ann. Mus. d'Hist. Nat. Nice,vol. 4 (for 1976), p. xxxiiio1-xxxiiio23.
Matsuno, K., K. Tanaka, A. Mizuno and M. Ishida(1964): Iwamizawa (Sapporo-14). Expl. Text.
Ceol. Map of Japan, scale 1 :50,000, 168+11 pp.,11 pis., map, Geol. Surv. Japan (in Japanese with
Engl. abstract).
Nagao, T. and T. Matsumoto (1939): A monograph of
the Cretaceous Inoceramus of Japan. Part I. Jour.
Fac. Sci., Hokkaido Imp. Univ., Ser 4, vol. 4, nos.
3 -4, p. 241-299, pis. 23-34.
Noda, M. (1988): A notes on Inoceramus tenuistriatus
Nagao et Matsumoto (Bivalvia) from the Upper
Turonian (Cretaceous) of Japan. Trans. Proc.
Palaeont. Soc. Japan, N.S., no. 151, p. 582-600,9
rigs.
Pergament, M. A. (1966): Zonal stratigraphy andInoceramus of the lowermost Upper Cretaceous of
the Pacific coast of the USSR. Trans. A cad. Sci
USSR. Ceol. bISt., vol. 149, 83 p., 36 pis. (inRussian).
Sornay, J. (1978): Precisions paleontologiques et stratigraphiques sur divers inocerames cenomaniens et,en particulier, sur ceux de la Sarthe figures par E.
Gueranger en 1867. Ceobios, no. 11, fasc. 4, p.
505 -515 (incl. 2 pis.).
- - (1980): Inoceramus schondorfi Heinz, une espece

865. Cenomanian Inoceramids from Japan - IV
mal connue du renomanien. Ann. PaMont. Invert.,
vol. 66, p. 43-47, pI. 1.
Tanaka, K. (1985): Cretaceous fossils from Japan heldin the Geological Survey of Japan. Chishitsu News,no. 371, p. 56-62 (in Japanese).

581

Woods, H. (1911): A monograph of the Cretaceous
Lamellibranchia of England, vol. 2, part 7.
Palaeontogr. Soc. Monogr. for 1911, p. 261-284,
pIs. 45-50.

m

Fukuoka
1liiJ, Hachioji /\.:E T, Hokkaido ~t tfij iii: , Ikushumbets (Ikushunbetsu) ~:ff: 7.iU ,Iwamizawa !5-J!71\, Katsurazawa tE71\, Kyushu :id-l'i, Mikasa .:::~, Nakayama .pUJ, Oyubari *6'~, Pombets (Ponbetsu) ~7.iU, Sendai {ilia, Shiyubari (Shuyubari) 3::6'~, Suido-no-sawa 7.Kiii:0)71\, Taki-no-sawa iIlO)71\, Tohoku JR~t, Tokyo JR#-, Tsukuba ~i1t.
*J;i)S!IR*-iz / ~=. 7 :/1Ii£1' / -iz =j A::<'-W. ~*O);.67.:>~ttfijiii:£ 1 ~~ : !I!!/l!HnH!tF.JT!I!!~~*~~;::1*~O)~*"(', ii' '? '"( EB.pil~~:ff:7.iUO).:::~II.p$ (-iz / ~ =. 7 :/ 1: $) 7.1' I? mt.: GSJ.

<<

F8275 ~f~*iI~J! '"(, iI,h,'"(iI' I? O)~rR~~m ire t.r. 7.:> e m:~ L., IliJ t:: ~:ff:7.iU£O)JR~t*~*,*6'~iIlO)71\O)nmm~$II(-iz/~='7:/~1:$)£0)~~O)n*~*e~~'"(*IliJ~~L.

t.:. -t O)ifii!i!*;:.n I? Ii EB.p iI~7 J! L. t.: J: ? ~;::, "Inoceramus etheridgei Woods" (~~;:: I.
scalprum Bahm e qj(~, ~Jlili I. virgatus Schlater O)!IR~t t.:li 1 ~'J!~~ e ~.n7.:» e~-(j;(-r7.:> iI~, IliJ {"*,,,~ (Ii rae) ~;:::lJQ.:t '"(, .p Wit: 0) iJl1i ~ 0) mJ!U:if L. 1,' 3:: JJ1J iI~ ~ ~ -r 7.:>. fit '? '"( I.
atlanticus (HeinzH;::~-(j;(-r7.:>ilt, nl!:O)nl1::Ilt!MJilt~~;::jjiJn~;::[!!]O)IIIl~HiYi~, -t.n~;::#'?'"(nI!:O)fIfU
lB ~ I. atlantic us e ~t.r. 7.:>. J: '? '"(1:gc GSJ ~*~ ~ !J l' 7', -to)ff!!.~"'{ =j !J l' 7'::<. e L. '"( ,~~ I. nodai ~~lL L., ~~. gc~ Lt.:.
t.r.:ro I. reachensis Etheridge, 1881 0) v!/ r !J l' 7'Ii Woods (1911, pI. 48, fig. 5; pI. 49, fig.
1) ;6~~~Lt.: ul. reachensis" clilK7.iU"('~7.:> C9H!il"('W-~*~t~*ilt~~) iI'l?, ~~~;::iili..-j~ Heinz (1936) iI~~~ L. t.: I. atlanticus lil*ffl L. '"( J: I, '.
I.virgatusli-iz/~=.7/f-¥$ (~r$~~) ~;::£-r7.:>. A,@]t&'?t.:I. nodaio)~*lilliJlIi
1:$~;::£-r7.:>ilt, ~1:$"('li/Nji-j"(';.67.:>. -to)/Nji-jO) ~ O)-e~, 7- "" - ~ =. 7:/ 1:$£0) I.
tenuistriatus Nagao et Matsumoto c O)m~liljij!it-e;.6 7.:>. (*~~ c 3frr L. '"(~~~!BfEBiI~~~
L.19881f.*~~;::gc~.) e;:0;6~tfij~-e~~0)~~;6~-iz/~='7:/£0) ul. tenuistriatus" ~¥ll
15- L. '"( 1,'7.:>. ~¥g~ J! '"( I, ,t.r.1, 'ii' I?WTali~k. 7.:>;6~, ~~ . gcJili 0) ~ 0) (1liJ IIi 1: $, 1Iif~;::.p$£) ~;::~ L. '"( Ii, -to) 1liJ:@li~-e, I. nodai c Lt.:n;6~ J: 1,' c ,\~Lb.n7.:>. ;: O)*UWT;6~:if L.I" c -r 7.:>c, I. nodai li-iz / ~ =. 7:/ 1:-¥$O)~~H:E~c L. '"(m:~c t.r.7.:> "(';.60?
f~*~ll~ • EB.pF,!:**Trans. Proc. Palaeont. Soc. Japan, N. S., No. 151, pp. 582-600,9 Figs., October 31, 1988

866. A NOTE ON INOCERAMUS TENUISTRIATUS NAGAO ET
MATSUMOTO (BIVALVIA) FROM THE
UPPER TURONIAN (CRETACEOUS) OF JA.PAN
MASA YUKI NODA
Fukagochi 5 kumi, Oita, 870

Abstract In the original description Inoceramus tenuistriatus Nagao et Matsumoto,1939 was well defined, but the species has not been always understood correctly by someforeign researchers. In this paper I. tenuistriatus is biometrically restudied on a population
sample from the type locality. The statistics are taken for eight characters on 30 left and 27
right valves. A revised description of I. tenuistriatus is given, including the result of thebiometric examination. I discuss the relationship of the redefined I. tenuistriatus with theso-called "I. (I.) tenuistriatus" (with or without query) from the Cenomanian of Euramerica
and the Pacific Coast of the USSR. It has been confirmed that the so-called "I. (l.)
tenuistriatus" should be morphologically discriminated from the sample specimens of the type
locality. In connection with this, I agree with Matsumoto and Tanaka (1988) in their suggestionthat the so-called "I. (I.) tenuistriatus" may be identical with I. nodai Matsumoto et Tanaka,
1988 from the Upper Cenomanian of Hokkaido.
The stratigraphic unit of the type locality of I. tenuistriatus is clearly assigned to theUpper Turonian on the evidence of associated species. Besides, "I. tenuistriatus" has beenreported to occur at several horizons other than the Upper Turonian in various areas of Japan,
the true range of this species is yet to be worked out further.

Introduction

1977 and Keller, 1982). But their specimens
differ from the type specimens in size, outline
and surface ornamentation, so far as theirillustrations are concerned. The authors may
have misunderstood the concept of this species.
Anyhow the species so-called "1. (1.) tenuistriatus" has begun to walk freely regardless ofthe type specimens and type locality. This may
have given undesirable influence even on thestudents in Japan.
Besides, Kauffman (1977a, p. 178) mentionedthat Japanese Turonian and Euramerican Cenomanian specimens appear to be identical externally, and also detailed study on their morphology still need to be done to demonstrate thatthey are conspecific rather than a case of
homeomorphy.

Inoceramus tenuistriatus Nagao et Matsumoto, 1939 was established on the basis of six
specimens from the Upper Turonian of thePombets area, central Hokkaido. In the originaldescription by Nagao and Matsumoto (1939, p.
272-274), this species is well defined by its own
characteristics with some extent of variation in
outline -and surface ornamentation.
Meanwhile, the occurrence of 1. tenuistriatus
in the Cenomanian rocks of Euramerica and East
Asia was recorded by several authors (Vereschagin et ai., 1965; Pergament, 1966; Kauffman, 1975, 1977b, 1978; Kauffman and Powell,
Received June 16, 1988; revised manuscript
accepted September 1, 1988
582

866. Inoceramus tenuistriatus

The present paper, therefore, aims to give aclear redefinition of /. tenuistriatus by means ofbiometry on a population sample from the type
locality. This would offer a foundation for the
precise comparison between this species and theso-called "/. (1.) tenuistriatus".
Before going further, I thank Emeritus Professor Tatsuro Matsumoto of Kyushu University
for his suggestion of this problem and kind help
throughout the present study including comment
on manuscript and loan of a large number of
specimens of his own collection now kept at
Kyushu University. I am indebted to Professor
Itaru Hayami of the University of Tokyo,
Emeritus Professor Tarnio Kotaka of Tohoku
University and Professor Makoto Kato of
Hokkaido University for their kindness in giving
facilities for the access to the syntypes. My
gratitude is also extend to Messrs. Kikuo Muramoto of Mikasa Museum, Takemi Takahashi,
Yoshitaro Kawashita of Mikasa and Masao Futakami of Kawamura Gakuen Women's University,
Chiba Prefecture for their help in the field workand loan of useful specimens.
MethodIn this paper, at first statistic method is583

applied for mens ural characters on a population
sample from the type locality. The specimens
examined do not necessarily represent one living
population in a strict sense, but are regarded as apopulation sample in a broad sense because they
were obtained from one and the same biostratigraphic unit (Zone of Mytiloides incertus) exposed on a continuous outcrop of a limited
extent.
Left and right valves are measured and taken
into statistics separately, on account of theinequivalveness. The mean values (m), standard
deviations (s) and Pearson's coefficient of variation (v=l OOsjm) of selected characters are calculated. Then the chi-square test is used for theevaluation of normal distribution in selectedcharacters. If the chi-square value (X2) is not
significant, Student's t-test is applied to evaluate
the significance of morphological difference
between left and right valves. Before the t-test is
adopted, F-test is made. If the F-value is significant, the t-value is calculated by Welch's method.
Average relative growth of shell length vs.
shell height and that of shell breadth vs. shellheight are examined separately for left and rightvalves. These are demonstrated by reduced majoraxes on logarithmic graph paper and expressedby the power functions [1 = fih a, b= fih a] andFigure 1. Basic morphology for measurements. A: lateral view of left valve, B: lateral view of right valve,
C: anterior view. h: shell height, I: shell length, b: shell breadth, s: length of hingeline, H: maximum linear
dimension from umbo to ventral extremity, L: maximum linear dimension perpendicular to H, a: anterior hinge
angle, f3: beak angle, angle of umbonal inflation, r: posterior hinge angle, il: obliquity, angle between
hingeline and H.

Masayuki NODA584

the correlation coefficient is calculated for ·eachof them. Isometric or allometric relationship foreach sample is evaluated by means of K-test on
the basis of sample size (N), growth index (a)and correlation coefficient (r).
The basic linear measurements and angles areshown in Fig. 1. For the method of measurements, the readers may refer to Noda (1983),
and for the procedure of statistics and theiranalyses, see Hayami (1969), Hayami and Matsukuma (1971) and Tanabe (1973).
Palaeontological description
Family Inoceramidae Zittel, 1881
Genus Inoceramus Sowerby, 1814
Type species:-Inoceramus cuvierii Sowerby,
1814.
Remarks:-Although the genus Inoceramus
has been divided into several subgenera, thespecific characters of Inoceramus tenuistriatus
Nagao et Matsumoto described below are wellharmonious with the definition of the nominate
subgenus by Cox (1969), except for its small
size. Hayami (1975) and Kauffman (1977a,
1978) already assigned the present species to thenominate subgenus, although without mentioning a reason. According to Matsumoto (personal communication, 1988), as the taxonomic
criteria at generic or sub generic level the shellstructure and hinge structure should be regarded
as more important than external characters.
Because the internal structure of I. tenuistriatus
is not clarified at present, therefore I have to use
Inoceramus in a broad sense in this paper.
Inoceramus tenuistriatus Nagao etMatsumoto, 1939
f'igures 5-1-7; 6-1-11; 7-1-11; 8-1-6; 91939 Inoceramus tenuistriatus Nagao et Matsumoto, p.
272-274, pI. 24, fig. 8; pI. 26, figs. 1-4.
1959 Inoceramus tenuistriatus: Matsumoto, p. 84.
non 1965 Inoceramus tenuistriatus: Vcreschagin,Kinasov, Parakechov and Terehova, p. 37, pI. 24,
figs. 1, 2.

non 1966 Inoceramus tenuistriatus (?): Pergament, p.
47,48, pI. 13, figs. 2-4; pI. 14, figs. 2-4.
1975 Inoceramus (Inoceramus) tenuistriatus: Hayami,
p.53.
1976 Inoceramus tenuistriatus: Noda and Matsumoto,no. 45-265, fig. 6.
1977a Inoceramus (Inoceramus) tenuistriatus: Kauffman, p. 178.
non 1977b Inoceramus tenuistriatus ?: Kauffman, p.
230, pI. 4, fig. 9.
non 1977 Inoceramus (Inoceramus) tenuistriatus ?:Kauffman and Powell, p. 66-68, pI. 2, fig. 5; pI.
3, figs. 7,9, 10.
1978a Inoceramus (Inoceramus) tenuistriatus ?:Kauffman, p. IV 4,5.
? 1978a Inoceramus (Inoceramus) tenuistriatus: Kauffman, p. IV 4, 5.
non 1978b Inoceramus (Inoceramus) tenuistriatus ?:Kauffman, pI. 8, fig. 9.
1980 Inoceramus tenuistriatus: Futakami, Tanabe andObata, pI. 1, fig. 4.
non 1982 Inoceramus tenuistriatus: Keller, p. 62-64,
pI. 1, fig. 3a, b.

Lectotype:-HK7192 (Nagao and Matsumoto,1939, p. 262, pI. 26, fig. 1) designated by
Pergament (1966, p. 47) without examining theactual specimen.
Material:-Ninety one specimens, that is,
JG.H2980a, b, 2981b, c from Loc. Ik2012;
JG.H2970, 2971a-f from Ik2013b; JG.H2863
a-I, 2977a, b from Ik2013d; GK.HI0088a-c
from Ik2013e; JG.H2783, 2862a, b, 2865a-f
from Ik2013h; JG.H2968a, b, 2972a-h, 2973
a-g, 2975, 2976a, b, 2978a-c, GK. H
8278a, b, 8280a, b, 8281, 8282, 8283a-c,8284 from Ik2013 (without record of further
subdivision); GK.H8279a, b from Ik2014a;
JG.H2969, 2974 from the Juichino-sawa (a little
stream) of Ik2014; JG.H2784a, b, 2977a, b from
Ik2014; UMUT.MM6484 (=TK.I-701), 6485a-c(=I-702a-c), 6485d (=1-700), HK7185, 7187,
7192, IGPS22751a, b, 22751', 22769 from
Ponbetu (Pombets), Ishikari Province (somewhere in the outcrop from Ik2012 to Ik2014,
although not precisely described in the originallabels) and JG.H2982b from Ik2727 of thePombets-Gono-sawa, of which fifty seven specimens are used for measurements and statistics.
The repositories of the examined specimens
are as follows: GK: Geological Collections,866. Inoceramus tenuistriatus
Kyushu University, Fukuoka, HK: GeologicalCollections, Hokkaido University, Sapporo,
IGPS: Geological and Paleontological Collections, Tohoku University, Sendai, JG: Collections of J onan Geological Association kept
tentatively in Noda's personal laboratory, Oita
and UMUT: Collections of University Museum,the University of Tokyo, Hongo, Tokyo.
Biometry:-Measurements on left and rightvalves are separately shown in Tables 1 and 2.

585

The frequency distribution of the characters
examined, i.e., a, f3, r, (5, Ilh, blh, L/H and sll,
are demonstrated in Fig. 2. As is clear from Fig.
2, the characters show roughly normal distribution in both valves. As to the beak angle (f3)somewhat different ranges are shown between
left and right valves. The simple ratio L/H isplatykurtic in the left valve and left skewed in
the right one. The biometric characters of theleft and right valves are separately shown in

Table 1. Measurements of Inoceramus tenuistriatus Nagao et Matsumoto (left valve).
linear dimension in mm.
specimen
IGPS22751
JG.H2783
JG.H2862a
JG.H2862f
JG.H2863b
JG.H2863d
JG.H2865a
JG.H2865e
JG.H2968a
JG.H2968b
JG.H2970
JG.H2971a
JG.H2971b
JG.H2972a
JG.H2972c
JG.H2973a
JG.H2973c
JG.H2973f
JG.H2974
JG.H2977a
JG.H2977b
JG.H2979a
JG.H2980
GK.HI0088a
GK.H10088b
GK.H8280b
GK.H8283a
GK.H8284
MM6485dHK7192

h

I

b

29.9
24.6
31.2
17.9
39.5
23.7
29.5
11.6
26.0
28.7
26.0
17.4
16.6
16.4
18.8
25.6
16.7
26.3
28.0
19.0
23.7
37.7
36.2
35.4
22.0
17.2
27.1
27.0
24.4
24.0

26.0
18.7
26.5
13.7
32.3
19.8
25.7
9.0
21.2
23.3
21.3
12.7
12.7
14.7
14.4
22.8
12.7
23.1
21.6
15.8
19.5
31.0
23.5
24.7
16.7
14.3
21.0
21.6
22.6
21.0

11.0
9.7
12.2
7.0
14.0
8.2
11.7
5.0
10.4
9.8
8.1
5.5
4.3
5.3
6.1
8.8
4.9
10.4
7.9
4.5
8.1
14.2
11.2
12.7
8.6
6.0
10.0
10.5
9.4
11.8

H

16.0 33.0
12.9 25.6
15.7 36.0
7.8 20.7
18.2 42.1
11.7 26.1
16.6 36.3
4.3 13.3
13.8 27.6
13.0 30.9
13.1 27.7
6.6 18.3
6.0 17.8
7.4 17.0
8.6 19.4
11.1 27.7
6.9 17.8
12.2 28.2
12.0 30.1
7.2 20.0
11.8 24.5
17.8 38.6
11.6 38.0
14.3 37.0
9.2 23.0
9.6 20.3
29.5
12.4 28.8
10.8 27.4
14.0 27.0

Laf3
27.0 109 80
19.3 107° 70°
28.0 107° 76°
14.0 101 ° 74°
33.2 100° 70°
93 ° 66°20.9
94° 69°26.6
96° 70°9.0
23.8 108° 78°
24.0 107° 81°
21.6 100° 80°
13.6 113° 83°
13.0
15.3 105° 80°
15.8 103° 80°
23.6 110° 76°
13.2 102° 80°
23.9 109° 84°
22.0 102 ° 76°
17.9 108°20.2 102° 81°
32.0 100° 81°
26.5 101 ° 85°
95° 84°28.0
17.1 107° 71°
98° 88°14.0
23.6 102° 83°
20.6 105° 84°
23.2 112° 89°
23.0 110° 82°

r

0

113
104°
115°
120°
118°
115°

71
79°
76°
71 °
67°
60°
61°
64°
78°
72°
70°
77°

104°
112°
123°
106°

119° 60°
121 ° 70°
120° 72°113° 71°
114° 69°112° 70°
110° 71°
106° 70°
114° 74°
121 ° 66°
109° 73°
101 ° 65°
116° 58°
125° 62°
117° 67°
127° 68°
120° 65°

I/h
0.87
0.76
0.85
0.77
0.82
0.81
0.87
0.78
0.82
0.81
0.82
0.73
0.77
0.90
0.77
0.89
0.76
0.88
0.77
0.83
0.82
0.82
0.70
0.70
0.76
0.83
0.77
0.80
0.93
0.88

b /h
0.37
0.39
0.39
0.39
0.35
0.35
0.40
0.43
0.40
0.34
0.31
0.32
0.26
0.32
0.32
0.34
0.29
0.40
0.28
0.24
0.34
0.38
0.31
0.36
0.39
0.35
0.37
0.39
0.39
0.49

L/H
0.82
0.75
0.78
0.68
0.79
0.80
0.73
0.68
0.86
0.78
0.80
0.74
0.73
0.90
0.81
0.85
0.74
0.85
0.73
0.90
0.82
0.83
0.70
0.76
0.74
0.69
0.80
0.72
0.85
0.85

sil
0.62
0.69
0.59
0.60
0.56
0.61
0.65
0.48
0.65
0.56
0.62
0.52
0.47
0.50
0.60
0.49
0.54
0.52
0.56
0.46
0.61
0.57
0.46
0.58
0.55
0.67
0.57
0.48
0.67

reference: I/h: simple ratio of shell length vs. shell height, b/h: simple ratio of shell breadth vs. shell height, H/L:
simple ratio of L vs. H, s/l: simple ratio of the length of hinge-line vs. shell height.
for others readers may refer to Fig. 2.

Masayuki NODA

586

calculated by Welch's method. The t-values are
significant at 5 percent limit in beak angle andsimple ratio b/h, but the differences of othercharacters are not significant. These suggest thatthe beak angle and the simple ratio b/h areimportant to examine the inequivalveness.
The average rel~tive growth of shell length vs.
shell height and that of shell breadth vs. shellheight are demonstrated in Fig. 3 and the data of
the reduced major axes are shown in Table 6.
Based on the growth index (a), correlation
coefficient (r) and sample size (N), the K-test is
adopted to evaluate the average relative growth.
The K-values obtained are 0.25,0.92, -1.15 and-0.24, all of which do not reject the hypothesis

Tables 3 and 4. As is clear from the coefficientsof variation, every character shows in general
small variation in each valve except for b/h ands/l. The results of chi-square test are also shownin Tables 3 and 4. The chi-square values (X2) are
generally smaller than the significant limit at the
5 percent level except the beak angle (f') of theleft valve and the posterior hinge angle ( r) of ·theright valve. The null hypothesis, therefore, would
not be rejected in general but some suspicion
remains.
The results of F-test and t-test between theright and left valves are shown in Table 5.
Because the F-value for the beak angle andsimple ratio s/l are significant, t-values wereTable 2. Measurements of Inoceramus tenuistriatus Nagao et Matsumoto (right valve).
linear dimension in mm.
specimen
IGPS22751
JG.H2784
JG.H2862b
JG.H2862d
JG.H2863c
JG.H2863e
JG.H2865b
JG.H2971c
JG.H2972b
JG.H2972e
JG.H2973b
JG.H2973d
JG.H2973e
JG.H2975a
JG.H2978
JG.H2979b
JG.H2980b
JG.H2981b
GK.H8278a
GK.H8278b
GK.H8279b
GK.H8282
MM6484
MM6485aMM6485bHK7185
HK7187

h

27.0
18.7
29.0
25.8
24.2
21.2
11.2
11.4
21.0
21.0
19.3
12.7
12.2
23.7
21.9
21.9
32.6
22.6
24.3
18.5
15.8
16.1
29.7
24.8
25.6
37.0
22.0

b

24.0
14.1
23.6
19.7
17.5
18.2
8.9
10.6
17.0
17.2
17.4
9.5
10.3
18.6
18.5
18.7
25.1
18.3
18.8
13.4
12.9
12.7
26.6
20.9
21.6
32.0
19.0

9.0
6.2
8.5
8.2
8.0
3.1
4.0
6.4
6.7
6.5
3.4
8.1
6.1
7.2
9.0
7.6
6.4
6.4
3.9
5.5
8.3
7.6
7.7
12.0
8.0

17.2
9.6
13.7
12.5
8.6
9.9
4.3
4.4
7.1
7.4
7.1
5.1
5.3
10.0
11.1
10.6
12.0
9.9
15.0
8.6
8.5
7.3
11.7
12.0
11.1
12.8

H

L

30.0
19.7
30.7
27.1
26.0
23.1
12.3
13.5
23.3
23.0
21.8
13.6
13.0
26.2
22.6
22.3
37.0
23.5
26.4
19.0
16.7
17.0
30.5
26.8
27.7
40.0
24.0

25.0
15.0
26.0
20.0
19.0
18.5
9.0
11.8
18.8
17.4
18.2
9.8
10.5
20.7
18.4
18.6
24.8
18.2
23.8
16.2
13.3
14.4
25.4
22.2
24.6
34.2
21.0

a
90°
100°
102°
103°
106°
102°
102°
94°
101 °
103°
96°

105°
110°
110°
105°
94°
109°
92°
98°
99°
105°
106°
104°
106°
105°
99°

~

90°
90°
90°
88°
85°
86°
86°
87°
86°
86°
87°
82°
98°
91°
91°
90°
86°
90°
84°
85°
88°
94°
97°
94°
84°
89°

r
0
115° 66°
113° 64°118° 69°
71°
106° 70°
105° 70°
69°
119° 69°
121° 63°121° 62°112° 60°
113°
117°
112°
118°
116°
111°
120°
115°
111°
125°
122°
116°
114°
112°

77°
72°
72°
64°
68°
64°
54°
53°
60°
64°
66°
68°
67°
72°
68°

I/h
0.89
0.75
0.81
0.76
0.72
0.86
0.79
0.93
0.81
0.82
0.90
0.75
0.85
0.78
0.84
0.85
0.77
0.81
0.77
0.72
0.82
0.79
0.91
0.84
0.84
0.86
0.86

b /h
0.33
0.33
0.33
0.34
0.38
0.28
0.35
0.30
0.32
0.34
0.28
0.44
0.28
0.33
0.28
0.34
0.26
0.35
0.25
0.34
0.28
0.31
0.30
0.32
0.36

L/H
0.83
0.76
0.85
0.74
0.73
0.80
0.73
0.87
0.81
0.76
0.83
0.72
0.81
0.78
0.83
0.83
0.67
0.77
0.90
0.85
0.80
0.85
0.83
0.83
0.89
0.86
0.88

s/I
0.72
0.68
p.58
0.63
0.49
0.54
0.48
0.42
0.42
0.43
0.41
0.54
0.51
0.54
0.60
0.57
0.48
0.54
0.80
0.64
0.66
0.57
0.64
0.57
0.51
0.67

866. Inoceramus tenuistriatus

587

Antero-dorsal margin concave in the left valve
and slightly so in the right, antero-ventral marginrounded, ventral margin asymmetrically curved,
passing gradually into the long posterior one,
posterior margin straight and forming an obtuse
angle (104° to 127°) with the hinge line, which isslightly longer than a half of shell length on
average.
Surface of shell almost smooth except forvery fine concentric lirae, low and narrow concentric rings frequently discernible on internalmould, each of which corresponds to a concentric lira. Low and broad concentric undulations may develop rarely.
Description:-The specimens
JG.H2968a(Figs. S-6A-C), 2970 (Fig. 6-3), 2973f (Fig. 8-2)
and IGPS227Sla (Figs. SolA-C) of left valve,
and JG.H2862 (Figs. 8-lC-D), 297Sa (Fig. 6-6),
2978 (Fig. 6-7) and IGPS227Sl b (Figs. S-2A-C)of right valve are typical form. JG.H286Sa, b

of isometry (-1.96 ;;;; K ;:;:; 1.96).
Specific characters: -Shell small, very thin,inequivalve and inequilateral. Left valve higher
than long, with simple ratio ljh=0.8l on average,
considerably inflated and gibbous both anteroposteriorly and along the growth axis (Fig. 4),
which is straight throughout growth; anterodorsal part perpendicular to the plane of valve
and more or less concave; posterior and posterodorsal part also steep, forming a step to a distinct
but small wing-like area; umbo situated at theanterior end, small and short, slightly projecting
beyond the hinge line and curved considerably
inwards and a little forwards; beak angle about
78° on average with small variation. Right valve
lower and less inflated in comparison with theleft; umbo terminal and inconspicuous with anearly rectangular beak; anterior part steep andposterior one gradually flattened, passing into awing-like area without any sharp boundary.

Table 3. Biometric characters of Inoceramus tenuistriatus Nagao et Matsumoto (left valve).

N

m
s
a

v
2

X 0.05

a

f3

i

il

l/h

b/h

L/H

s/l

29
103.7

28
78.6

27
114.6

29
68.9

30
0.810

30
0.355

30
0.783

29
0.567

5.41

6.01

6.71

5.49

0.05750.05220.06720.0670

5.31
5.23

5.90
7.65

6.58
5.86

5.39
7.97

0.05657.10

0.051314.70

0.06170.0659

8.01

11.82

4.14
v=3

17.33
11=1

3.72
11=1

3.17
11=1

3.17
11=1

5.51
11=2

2.33
II =1

2.95
II =1

reference: N: sample size, m: mean value, s: standard deviation, a: population standard deviation, v: Pearson's
coefficient of variation, X~.05 : chi-square value at 0.05 significant limit, II: degree of freedom, underline: significant
Table 4. Biometric characters of Inoceramus tenuistriatus Nagao et Matsumoto (right valve).
a

f3

T

il

l/h

b/h

L/H

s/l

m

26
101.8

26
88.6

23
115.3

26
66.2

27
0.819

25
0.321

27
0.808

26
0.563

s
a

5.34
5.24

3.95
3.87

4.92

5.48

0.05590.04120.0572

0.09584.81

5.37

0.05490.04040.0562

0.0965

v

5.25

4.46

4.27

8.28

6.83

12.83

7.08

17.50

2

3.58
11=2

2.77
11=1

4.06
11=1

0.90
11=1

1.38
II =1

2.03
11=1

2.12
11=2

1.68
:;=2

N

XO.05

Masayuki NODA

588

Table 5. F-test and Student's t-test between left and right valves for selected characters of
Inoceramus tenuistriatus Nagao et Matsumoto.
a

~

r

il

I/h

b/h

L/H

s/I

m
s

29
103.7
5.41

28
78.6
6.01

27
114.6
6.71

29
68.9
5.49

30
0.810
0.057530
0.355
0.052230
0.783
0.062729
0.567
0.0670Fvalue1.02642.31501.86001.00371.05831.60531.2015

2.1623

0

•

0

0

0

0

0

•

N

LV

significancet valuesignificance
N

RV

m
s

reference:

1.308

7.256

26
101.8
5.34

0.414

•

0

1.823

0

26
88.6
3.95

0.598

23
115.3
4.92

26
66.2
5.48

1.556

2.641

0.174

0

•

0

0

27
0.819
0.055925
0.321
0.041227
0.808
0.057226
0.563
0.09850

LV: left valve, RV: right valve,.: significant, 0: not significant
For others readers may rcfer to Table 3 and Fig. 2.

Table 6. Data of the average relative growth of Inoceramus tenuistriatus.
a

LV

RV
reference:

~

log~

h'

I'

1.380 I

1.2869

I vs. h

1.011

0.779

b vs. h

1.090

0.264

0.10840.57841.3801

1 vs. h

0.936

0.994

0.00261.3214b vs. h

0.984

0.331

0.48011.3245b'

0.92591.23410.8223r

NK

0.9712

30
30

.0.25

0.87090.950827- 1.150.938525-- 0.240.92

a: growth index (slope of the reduced major axis), ~: Y interccpt, 11': mean of h' (h =logh), T: mean ofJ' (J'=logl), b': mean of b' (b l =logb), r : correlation coefficient, N: sample size, K: K-value(Fig. 6-11), 2971a, b (Fig. 6-12),2974 (Fig. 7-7),
GK.H10088a (Figs. 7-9A-C), 8280b (Fig. 5-3),
JG.H2784 (Fig. 8-6), 2863c (Fig. 5-7) and 2865
(Fig. 6-11) are considerably elongated along the
growth axis, whereas the specimens JG.H2971c(Fig. 6-12), 2972c (Fig. 7-11) and GK.H8278a(Fig. 7-10) are somewhat broadened. A specimen
JG.H2982 (Fig. 9) from Loc. Ik2727m of thePombets-Gono-sawa is considerably inflated withunusually globose umbo for the right valve. On
the surface of the specimens JG.H2968a (Figs.
5-6A-C), b (Figs. 6-1A, B), 2972a, b, c (Fig.
7-11), 2973e, 2979, 2980 and GK.H8278a (Fig.
7-10) which preserved shelly material, fine concentric lirae are precisely shown, but the fineornament is defaced from its brittle surface.
JG .H2784 (Fig. 8-6), 2863b (Fig. 5-7), 2865
(Fig. 6-11), 2977 (Fig. 5-5), GK.H8280 (Fig.
6-8), 8282 (Fig. 7-8), 8278b (Fig. 7-2), 10088b(Fig. 7-1) and 10088a (Fig. 7-9) preserved theinner layer only, on which minor concentric ringsand striae are clearly developed. JG.H2971 (Fig.
6-12), 2982 (Fig. 9) and IGPS22756b (Figs.
5-2A-C) are internal moulds which are ornamented by weak, low and round-topped concentric rings. Shell layer partly remains on the
IGPS22751a(Figs.
5-1A-C),
specimens
JG.H2970 (Fig. 6-3), 2973f (Fig. 8-2), 2975a(Fig. 6-6), 2978 (Fig. 6-7) and 2869 (Figs.
7-1A-E). The concentric lirae on the surface

866. Inoceramus tenuistriatus~

Dlv

Nt v =29

50_RV

NRV=26589

N tv = 27
50.0N llv =2 650

N l V =29"

N ll v = 2 3

N l1 v = 26

50

'0

'0

30

~O

JO

20

JO

:

~

~

~

50

~

~

~

C?

JO

~

:::

0(

~

~

~

~

~

~

~.

::

~

F

Ntv= 30~

N lV =30

F"

Ntv

NRv= 2750

NRV =2550

Nil ... = 27

'0

.0

30

30

,0

,0

10

J0

= 30

-

-~

1

~

5: I

~

..;

;::

~

:?:

J'

N tv = 29
NR V

=26

.0

~

~
~

~

~

e

.;

.;

c

~

~
~

I/h

~
~

~

~

.;

Figure 2.

Hist ogram showing the frequen cy of select ed characters.

may correspond to the concentric rings on theinternal mould as Matsumoto and Noda (1986 , p.
410) already mentioned. On the surface of
JG.H2968a (Figs. 5-6A- C) , 2968b, (Fig. 6-3) ,2977c, GK.H8278a (Fig. 7-10) , the concentriclirae are superimposed on minor concentric
undulations which are indistinct , low and irregu·
lar in distance. As an exceptional case, concent ric
riblets of second order by Matsumoto and Noda
(1986, p. 4 11 ) are discernible on JG .H2784 (Fig.
8-4).
Remarks:-Although some of the specificcharacters described above are based on biometric analyses , no sigruficant alteration isneeded to the original definition of the species
by Nagao and Matsumoto (1939 , p. 272) . Additionally the following points are clarified throughthe present study. (1) The extent of variation in
the shell form is small except the shell convexity
and simple ratio s/I as shown in Tables 3 and 4.

(2) The shell is not greatly inequivalve, but there
is a distinct difference between left and rightvalves in the beak angle «(3 ) and shell convexity(b/h). (see Table 5) (3) Through the K-test , theaverage relative growth has been confirmed that
there is no significant change in the measW'ed
characters with growth. For instance , the valuesof l/h and b/h are almost constant throughout
growth.
Comparison and discussion: - The specimens
described and illustrated unde r "1. (1.) tenuistriatus" by authors , with or without a query,from the Cenomanian of various regions of theworld are quite questionable in specific identification.
The specimens described by Pergament,
3580-138 , 139 , 140 (Pergament , 1966, pI. 13,
figs . 2- 4), 3580· 141, 142 and 143 (pI. 14, figs .
2- 4) from the Cenomanian (and Turonian ?) of
Sakhalin and the Pacific Coast of the USSR,Masayuki NODA

590

LV
b
mm

~:~:~~:''''/

AO

RV

I

b
mm

1= O. 994ho. 936
r=0.9508

AO

N= 27

N=30

..

30

30

20

20

..

.

0
0

o

0

10
9

10
9

8
7

8
7

0
0

6
0

5

0
0
0

o

6

0

b=0.264h1.090
0

r = 0.8709

A

0

0

A

N=30

2

2+<~---------'-----.----r--r----Figure 3.
right valve.

20

30

N=25

0

3

910

r=0.9385

0

0

3

8

b=O. 331 hO. 98A

5AO

50 hmm

8

910

20

30

AO

50

hmm

Diagram showing the average relative growth of Inoceramus tenuistriatus. LV: left valve, RV:

RV

JG.H2863b

GK. H82780

JG. H 28620

J G. H2975 0
lOmm

GK.H100880

JG.H2862b

Figure 4. Shell convexity of Inoceramus tenuistriatus, LV: left valve, RV: right valve. left side: crosssection along the growth axis, right side: cross section along the line perpendicular to the growth axis at thehighest point of shell convexity, a: anterior, p: posterior

866. Inoceramus tenuistriatus
resemble the present species in general aspect.
But from the t-test between the specimens andthe population sample from the type locality,
significant difference has been confirmed. The
beak angle of the Pergament's specimens
3580-140 and 142 are 95° and 98°, left and rightvalves respectively and the t-values between apair of samples are 2.681 and 2.335 which arelarger than 2.052 and 2.060 at 5 percent significant limit, at degree of freedom 27 and 25 forthe left and right valves respectively, and also thet-value of the simple ratio l/h between the
population sample of the type locality and3580-143 is 3.250, which is also larger than
2.042 at the 5 percent significant limit. Moreover, the simple ratio l/h of 3580-143 (1/h=1.00)
is outside of the possible range (m ± 3s =0.697~0.983) of the population sample. In
addition the major concentric ribs are predominant in the Russian specimens. From above
examination, the Russian specimens, therefore,
can be at least morphologically discriminatedfrom the present species.
The specimens USNM169399, 169401,
169402 and 169403 of Kauffman and Powell(1977) from the Upper Cenomanian of Oklahoma are clearly distinct from the Japanese
specimens from the Upper Turonian of the type
locality by their much larger size, weaker convexity and well-developed major concentric ribs.
The specimens described by Keller (1982)
from the Middle Cenomanian of the Sack-Mulde
area near Alfeld, West Germany are also discriminated from the studied specimens of J.
tenuistriatus from Hokkaido by their larger ratioof L/H (Keller, 1982, p. 63, fig. 30), weaker
convexity (observed by photographs), indistinct
posterior wing and major concentric ribs developed in the early growth-stage onward. If t-test
were applied for a pair of left and right valves of
the German specimens and also between theGerman and Japanese specimens, the result
would show clear difference. But I refrain, here
from the evaluation because of insufficient information on the German specimens.
In connection with the above comparison,
according to Matsumoto's personal communica-

591

tion, Matsumoto and Tanaka have recently established Inoceramus nodai on sufficiently
numerous specimens from the Upper Cenomanian strat of Hokkaido. They suggested thatwhat was described under "J. (J.) tenuistriatus"(with or without a query) by several authors
from the Cenomanian of oversea regions may be
preferably transferred to J. nodai. I am fully
agreeable with their view. I have hesitated for along time to give comments on the specificassignment of "J. (1.) tenuistriatus". The youngshell of J. nodai Matsumoto et Tanaka, 1988
closely resembles the right valve of the present
species in marginal outline, shell convexity,
nearly straight growth axis and fine concentriclirae, but differs gradually with growth from thepresent species by comparatively larger size,
anteriorly curved growth axis, development of
the major concentric ribs and slightly inequivalve
or subequivalve with less gibbous and gently
convex shell.
Previously Nagao and Matsumoto (1939)
pointed out the resemblance between the present
species and J. etheridgei Woods, 1911 (p. 278, pI.
49, figs. 2-4) from the Lower Chalk of Englandand Matsumoto (1959, p. 84) once suggested
that J. tenuistriatus might be preferably separated as a subspecies of J. etheridgei, but henoticed some difference and evidently delayed
occurrence in age. Kauffman (1977a, p. 178;
1978, p. iv 4-5) also regarded the present species
as a member of the "J. etheridgei lineage"
Incidentally J. etheridgei in the sense ofWoods (1911) was a homonym of J. etheridgei
Etheridge, J r., 1901 and renamed as J. scalprum
Bohm, 1915, which is currently regarded as asubspecies or variety of J. virgatus Schliiter (seeMatsumoto et al. 1987, p. 157-162; Sornay,
1978, p. 510).
Following Matsumoto and Tanaka (1988), theorigin of J. nodai may be ascribed to a form of J.
virgatus (=J. virgatus scalprum of the Keller'ssense). According to Matsumoto et al. (1987) J.
virgatus is considerably variable in shell form,
ontogenetic change of obliquity and ornamentation.
In connection with the lineage of J. tenuis-

592

Masayuki NODA

866. Inoceramus tenuistriatus
triatus, it is noteworthy to see that the specimensof 1. nodai from a higher stratigraphic position,ie., the upper part of the Upper Cenomanian in
the Oyubari area, Hokkaido are generally smaller
in size than its holotype from the lower part of
the Upper Cenomanian in the Ikushumbets area.
The immediate ancestor of 1. tenuistriatus which
could link phylogenetically with 1. nodai is so far
unknown and should be search for from thelower part of the Turonian. Besides the species of
1. inaequivalvis Schluter from the Middle
Turonian of Euramerica and 1. submametensis
Zonova, 1982 from the Turonian of the Pacific
Coast of the USSR may be related to the lineageof 1. tenuistriatus. I withhold, at present, todiscuss the detailed phylogenetic consideration,
since it is a side issue from the aim of this study.
Occurrence:-For some reasons, some authors
thought that the original location and stratigraphic position of 1. tenuistriatus were obscure.
Nagao and Matsumoto (1939, p. 273) reported
clearly that the six syntypes are all from thelowest part of the Upper Ammonite beds along
the Pombetu [=Pombets in this and other recent
papers]. One of the authors (T. M.) told me that
this means the continuous outcrop of a unit
(Member IlIa') of fine-sandy siltstone, which is
subdivided into Ik2012, Ik2013 and Ik2014 forconvenience. This outcrop is now celebrated forthe occurrence of several important species, as
has been already reported by Matsumoto (1965,1984), Matsumoto et al. (1981) and Matsumoto
and Noda (1983). Its location is shown in Fig. 10of this paper, Long. 141 0 58'46"-50"E, Lat.
43 0 16'20"-23"N. This unit belongs to the Zone
of Mytiloides incertus (Matsumoto and Noda,
1983; Noda 1984).
Numerous specimens are included in calcareous nodules in fine-sandy siltstone of Unit
IlIa' of the Upper Yezo Group; commonly593

closed or articulate and rarely separated valves.
Associated megafossils listed by Matsumoto et al.
(1981) are as follows: Mytiloides incertus(Jimbo), M sp., Inoceramus pedalionoides Nagao
et Matsumoto, 1. (1.) sp., Damesites ainuanus
Matsumoto, Subprionocyclus neptuni (Geinitz),
S. norma lis (Anderson), Prionocyclus abberrans
Matsumoto, P. cobbani Matsumoto, Reesidites
minimus (Hayasaka et Fukada), Lymaniceras
planulatum Matsumoto, Nipponites bacchus
Matsumoto et Muramoto, Scalarites densicostatus Matsumoto, Scaphites aff. subde/icatulus Cobban et Gryc, S. yonekurai Yabe,
Otoscaphites aff. prerml (Anderson) andSciponoceras intermedium Matsumoto et Obata,of which M. incertus, S. neptuni and S. norma lis
are world-wide zonal indices of the Upper
Turonian. A lot of carbonized vegetable drifts
and amber or retinite are frequently contained in
nodules.
A single specimen JG.H2982 is from Loc.
Ik2727m, the upper reaches of the PombetsGono-sawa (Takino-sawa or Takiyoshi-zawa), a
tributary of the R. Pombets, together with
Lymaniceras planulatum. For details readers may
refer to Matsumoto and Noda (1985, p. 265).
The occurrence of 1. tenuistriatus has been
already recorded by a number of researchers(Yoshida and Kambe, 1955; Igi et al., 1958;
Tsushima et al., 1958; Tanabe, 1972; Matsumoto
and Okada, 1973; Obata and Futakami, 1975;
Tanabe et al., 1977; Hirano et at., 1980, 1981;
Futakami, 1982; Futakami and Miyata, 1983;
Sekine et al., 1985), in various areas, e.g.,
Soashibets, Hatonosu, Manji, Oyubari and Osawa(=Kamihobets) areas of central Hokkaido; Obiraarea, northwestern Hokkaido and Uwajima area,
western Shikoku. Some specimens from thepreviously listed localities may, however, needreexamination with reference to the present~ Figure 5.
Inoceramus tenuistriatus Nagao et Matsumoto. 1. IGPS colI. cat. no. 22751a, left valve, x 1.17.
from Pombets, precisely undescribed on the original label, probably Ik2012-2014. One of the syntypcs. A:
lateral view, B: anterior view, C: dorsal view. 2. IGPS colI. cat. no. 22751b, right valve, x 1.25, same locality. A:
lateral view, B: anterior view, C: dorsal view. 3. GK.H8284, left valve, x 1.17. Loc. Ik2013. 4. IGPS colI. cat. no.
22751-2, left valve, x 1.17. from Pombets. A: lateral view, B: anterior view. 5. JG.H2979, left valve, x 1.1. Loc.
Ik2014. 6. JG.H2968a, left valve, natural size. Loc. Ik2013. A: lateral view, B: anterior view, C: dorsal view. 7.
JG.H2863, natural size. Loc. Ik2013d.

594

Masayuki NODA

866. Inoceramus tenuistriatus
redefini tion.
The material of I tenuistriatus dealt with in
this paper is limited to the Upper Turonian of
Hokkaido, but the true stratigraphic range andgeographic distribution of this species are to beworked out further.
Conclusion
To solve the taxonomic and biostratigraphic'
I
confusion of Inoceramus tenuistriatus,
attempted to restudy this species by means ofbiometric examination on a population sample
from the type locality. The results obtained are
as follows.
1. In addition to the original definition by
Nagao and Matsumoto (1939), an extent ofvariation, a degree of inequivalveness and ontogenetic change of shell form are quantitatively
displayed by means of statistics, t-test andanalysis of the average relative growth respectively. For example, (1) the characters examined show in general a small variation (smaller
than 9.00 in Pearson's coefficient of variation)
except for blh and sll in both valves, (2) the
inequivalveness is mainly expressed by thedifference in beak angle ( =78.6° in LV and
88.6° in RV on average) and simple ratio blh(0.355 in LV and 0.321 in RV on average) and(3) the average relative growth is nearly isometric, which implies that the shell form isalmost invariable at every stage of growth.
2. The so-called "I (I) tenuistriatus" (with orwithout a query) from various horizons of the
Cenomanian of Euramerica and the Pacific Coastof the USSR is morphologically distinct from the
population sample from the type locality, as
shown by the result of t-test and other examination.

595

3. I agree with Matsumoto and Tanaka (1988)
in their remarks that the specimens socalled "I (I) tenuistriatus" from oversea regions
would be preferably transferred to I nodai
Matsumoto et Tanaka, which was established on
the specimens from the Upper Cenomanian of
the Ikushumbets and Oyubari areas, central
Hokkaido.
4. Some of the previously recorded specimensfrom various areas of Japan may need reexamination with reference to the result of this study.
The numerous specimens of I tenuistriatus dealt
with in this paper are all from the Upper
Turonian of Hokkaido. The true stratigraphic
range and geographic distribution of this species
are yet to be worked out further.
5. The problem as to the origin and immediate ancestor of I tenuistriatus is likewise remains
unsolved.
References cited
Bohm, J. (1915): Zusammenstellung der Inoceramen
der Kreideformation (Nachtrage). Jahrb. preuss.
geol. Landesanst. Hannover, vol. 35, no. 3, p.
595-599.
Cox, L. R. (1969): Inoceramidae. In Moore, R. C. (ed.),Treatise on invertebrate paleontology, part N,
Mollusca 6, p. N314-N321, Geol. Soc. Amer. &Univ. Kansas Press.
Futakami, M. (1982): Cretaceous stratigraphy andammonite assemblages of the Hatonosu area,
central Hokkaido. Jour. Ceol. Soc. Japan, vol. 88,
no. 2, p. 101-121, pIs. 1, 2 (in Japanese withEnglish abstract).
- - , and Miyata, Y. (1983): The Upper Turonian
ammonite assemblages in the western part ofcentral Hokkaido, with special reference to thephyletic interpretation of Turonian Collignoniceratids. Jour. Ceol. Soc. Japan, vol. 89, no. I, p.
31-40, pIs. 1, 2 (in Japanese with English abstract).

~ Figure 6.
Inoceramus tenuistriatus Nagao et Matsumoto. 1. JG.H2968b, left valve, natural size. Loc.
Ik2013. A: lateral view, B: dorsal view. 2: JG.H2973b, right valve, x 1.35. Loc. Ik2013. 3. JG.H2970, left valve,x 1.25. Loc. Ik2013b. 4. UMUT.MM6484=TK.l-701, right valve, natural size. from Pombets, precisely unknown.
One of the syntypes. 5. UMUT.MM6485=TK.l-700, right valve, x 1.15. from Pombets. One of the syntypes. 6.
JG.H2975a, right valve, x 1.25, Loc. Ik2013. 7. JG.H2978, right valve, x 1.25. Loc. Ik2013. 8. GK.H8280, left
valve, x 1.25. Loc. Ik2013. 9. JG.H2973a, left valve, x 1.25. Loc. Ik2013. 10. UMUT.MM6485a=TK.I-702a,right valve, natural size. from Pombets. precisely unknown. One of the syntypes. 11. JG.H2865, natural size,
Loc. Ik2013h.

596

Masayuki NODA

866. Inoceramus tenuistriatus- - , Tanabe, K. and Obata, I. (1980): Characteristicsof the megafossils assemblages in the Pombets area,
central Hokkaido. Bull. Kitakyushu Mus. Nat.
Hist., no. 2, p. 1-10 (in Japanese with English
abstract).
Hayami, I. (1969): Mensuration of fossils and statistics- an example of palaeontological exercise - Sci
Repts. Dept. Geoi, Kyushu Univ., vol. 10, no. 2, p.
67 -90 (in Japanese with English abstract).
- - (1975): A systematic survey of the Mesozoic
bivalvia from Japan. Univ. Mus. Univ. Tokyo, Bull
10, p. 1-228, pis. 1-10.
- - and Matsukuma, A. (1971): Mensuration of fossils
and statistics - Analysis of allometry and variation-. Sci Repts. Dept. Geol, Kyushu Univ., vol. 10,
no. 3, p. 135-160 (in Japanese with English
abstract).
Hirano, H., Ando, H., Hirakawa, M., Morita, R. andIshikawa, T. (1980): Biostratigraphic study of theCretaceous System in the Oyubari area, Hokkaido.
Part 1. Gakuiutsu Kenkyu, School of Educ.,
Waseda Univ., Ser. BioI. & Geoi, vol. 29, p. 37-46(in Japanese with English abstract).
- - , - - , - - , - - and - - (1981): Biostratigraphic study of the Cretaceous System in the
Oyubari area, Hokkaido. Part 2. Ibid., vol. 30, p.
33-45 (in Japanese with English abstract).
Igi, S., Tanaka, K., Hata, M. and Sato, H. (1958):
Horokanai (Asahikawa-39), Explanatory text ofthe geological map of Japan, 1 :50000. Geol. Surv.
Japan, 55+9pp (in Japanese with English abstract).
Kauffman, E. G. (1975): Disposal and biostratigraphic
potential of Cretaceous benthonic bivalvia in theWestern Interior. Geol. Assn Canada, Special
Paper, 13, p. 163-194.
- - (1977a): Systematic, biostratigraphic and biogeographic relationships between Middle Cretaceous
Euramerican and North Pacific Inoceramidae.
Palaeont. Soc. Japan, Special Papers, no. 21, p.
169-212.
- - (1977b): Illustrated guide to biostratigraphicallyimportant Cretaceous Macrofossils, Western Interior Basin, U. S. A. The Mountain Geologist, vol.
14, nos. 3-4, p. 225-274, pis. 1-32.
- - (1978): British Middle Cretaceous Inoceramid biostratigraphy. Ann Mus. d'Hist. Nat. Nice [for1976], vol. 4, p. 1-12.
- - and Powell, J. D. (1977): Upper Cretaceous fossils~

597from Cimarron County, northwestern Oklahoma.
in Kauffman, E. G., Hattin, D. E. and Powell, J.
D.: Stratigraphic, paleontologic and paleoenvironmental analysis of the Upper Cretaceous rocks in
Cimarron County, northwestern Oklahoma. Geol.
Soc. Amer. Mem, vol. 149, no. 2, p. 1-150, pis.
1-11.
Keller, S. (1982): Die Oberkreide der Sack-Mulde bei
Alfeld (Cenoman - Unter-Coniac) Lithologie, Biostratigraphie und Inoceramen. Geol. Jb., vol. 64, p.
3-171, pis. 1-8.
Matsumoto, T. (1959): Zonation of the Upper
Cretaceous in Japan. Mem Fac. Sci, Kyushu
Univ., ser. D, vol. 9, no. 2, p. 55-93, pis. 6-11.
- - (1965): A monograph of the Collignoceratidae
from Hokkaido. part 1. Ibid., vol. 16, no. 1, p.
1-80, pis. 1-18.
- - (1984):
The
so-called
Turonian-Coniacianboundary in Japan. Bull Geol. Soc. Denmark, vol.
33, p. 171-181.
- - , Asai, A. and Hirano, H. (1987): Some Inoceramids (Bivalvia) from the Cenomanian(Cretaceous) of Japan-II. Three species from
Hokkaido, well known abroad but hitherto undescribed in Japan Trans. Proc. Palaeont. Soc. Japan,
N. S., no. 147, p. 146-164,8 Pigs.
- - , Putakami, M., Tanabe, K. and Obata, 1. (1981):
Upper Turonian ammonite assemblages in the
Pombets area, central Hokkaido. Bull. Kitakyushu
Mus. Nat. Hist., no. 3, p. 1-10 (in Japanese withEnglish abstract).
--and Noda, M. (1983): Restudy of Inoceramus
incertus Jimbo with special reference to its biostratigraphic implication. Proc. Japan Acad., vol.
59, ser. B, no. 5, p. 109-112.
- - and - - (1985): A note on an Inoceramid
species (Bivalvia) from the Lower Coniacian(Cretaceous) of Hokkaido. Trans. Proc. Palaeont.
Soc. Japan, N. S., no. 140, p. 263-273, pis.
41-44.
- - and - - (1986): Some Inoceramids (Bivalvia)
from the Cenomanian (Cretaceous) of Japan-I.
New or little known four species from Hokkaido
and Kyushu. Ibid., no. 143, p. 409-421, pis.
81-85.
- - and Okada, H. (1973): Saku Formation of the
Yezo geosyncline. Sci Repts. Dept. Geol., Kyushu
Univ., vol. 11, no. 2, p. 275 -309 (in Japanese with

Figure 7. Inoceramus tenuistriatus Nagao et Matsumoto. 1. GK.H10088b, left valve, x 1.17. Loc.
Ik2013e, A: lateral view, B: anterior view. 2. GK.H8278b, right valve, x 1.25. Loc. Ik2013. 3. GK.H8283a, left
valve, x 1.13. Loc. Ik2013. 4. GK.H8279, right valve, x 1.19. Loc. Ik2014a. 5. GK.H8281, right valve, x 1.19.
Loc. Ik2013. 6. UMUT.MM6485c=TK.I-702c, right valve, x' 1.18. from Pombets. One of the syntypes. 7.
JG.H2974, left valve, x 1.25. Loc. Ik2014. 8. GK.H8282, right valve, x 1.18. Loc. Ik2013. 9. GK.H10088a, left
valve, x 1.25. Loc. Ik2013. 10. GK.H8278a, right valve, natural size. Loc. Ik2013. 11. JG.H2972, natural size.
Loc. Ik2013.

598

Masayuki NODA

599

866. Inoceramus tenuistriatus, . . - - - - - - - - - - - - - - - _ , - - -- ,"3'18'-··· lk2727

IOOOm'======- ="I kushunbe t S

Figure 9. Inoceramus tenuistriatus Nagao etMatsumoto. JG.H2982, right valve, natural size. Loc.
Ik2727m. associated with Lymaniceras planulatum
Matsumoto.

English abstract) .
- - and Tanaka, K. (1988): Some Inoceramids (Bivalvia) from the Cenomanian (Cretaceous) of JapanIV. An interesting new species from Hokkaido.
Trans. Proc. Palaeont. Soc. Japan, N. S. , no. 151 ,p. 570 - 581, 15 rigs.
Nagao, T. and Matsumoto, T . (1939): A monograph of
the Cretaceous Inoceramus of Japan. Part I. Jour.
Fac. Sci., Hokkaido Imp. Univ., ser. 4, vol. 4, nos.
3 and 4, p. 241-299 , pis. 23 - 34.
Noda, M. (1983): Notes on the so-called Inoceramus
japonicus (Bivalvia) from the Upper Cretaceous ofJapan. Trans. Proc. Palaeont. Soc. Japan, N. s., no .
132, p. 191-219, pis. 41-46.
- - (1984): Notes on Mytiloides incertus (Cretaceous
Bivalvia) from the Upper Turonian of the Pombets
area, central Hokkaido. Ibid ., no. 136, p.
455 - 473 , pis. 84 -86.
- - and Matsumoto, T. (1976): Atlas of Japanesefossils. no. 45, Mesozoic molluscan fossils of Japan
4 (Cretaceous Inoceramus) , Tsukiji Shokan, Tokyo+- FigureS.

Figure 10. Map showing the type locality of
Inoceramus tenuistriatus Nagao et Matsumoto, in
the Pombets area, central Hokkaido.

(in Japanese) .
Obata, I. and rutakami, M. (1972): Cretaceous stratigraphy of the Manji area, Hokkaido. Bull. Natn.
Sci. Mus. Ser. C (Ceol.), vol. 1, no. 3, p. 93-110 ,pis. 1,2 (in Japanese with English abstract).
Pergament, M. A. (1966): Zonal stratigraphy andInoceramus of the lowermost Upper Cretaceous on
the Pacific Coast of the USSR. Trans. A cad. Sci,
USSR, Ceol. Inst., vol. 146, p. 1 -8 0, pis. 1-36 (inRussian) .
Sekine, H., Takagi, A. and Hirano , H. (1985): Biostratigraphical study of the Upper Cretaceous of thenortheast part of the Obira area, Hokkaido. Fossils,
no. 38, p. 1 - 15 (in Japanese with English abstract).
Sornay , J. (1978): Precisions paleontologiques et mati-

Inoceramus tenuistriatus Nagao et Matsumoto . 1. JG.H2862, ca x 1.25. Loc. Ik2013h. A:
lateral view of 2862a (left valve), B: posterior view of 2862a, C: lateral view of 2862b (right valve), D: posteriorview of 2862b, E: dorsal view of articulated both valves. 2. JG.H2973f, left valve, x 1.25. Loc. Ik2013. 3.
GK.H8283b , right valve, x 1.25. Loc. Ik2013. 4. JG.H2784 , right valve, x 1.27. Loc. Ik2014. 5. JG .H2977b, left
valve, x 1.25. Loc. Ik2013d. 6. GK.H8277 , natural size. Loc. Ik2014a, associated with Ly maniceras planulatum
Matsumoto.

Masayuki NODA

600

graphiques sur divers Inodirames Cenomaniens et,en particulier, sur ceux de Ia sarthe figures par E.
Guernger en 1867. Geobios. no. 11, fasc. 4, p.
SOS -SIS, pis. 1, 2.
Tanabe, K. (1972): Stratigraphy of the Cretaceous
formation in the Uwajima District, Ehime Prefecture, Shikoku. Jour. GeoL Soc. Japan, vol. 78,
no. 4, p. 177 -190 (in Japanese with English
abstract).
- - (1973): Evolution and mode of life of Inoceramus(Sphenoceramus) naumanni Yokoyama emend., an
Upper Cretaceous Bivalve. Trans. Proc. Palaeont.
Soc. Japan, N. S., no. 92, p. 163-184, pis. 27,28.
- - , Hirano, H., Matsumoto, T. and Miyata, Y.
(1977): Stratigraphy of the Cretaceous deposits in
the Obira area, northwestern Hokkaido. Sci Repts.
Dept. Geol., Kyushu Univ., vol. 12, no. 3, p.
181-202 (in Japanese with English abstract).

Tsushima, K., Tanaka, K., Matsuno, K. and Yamaguchi,
S. (19S8): Tappu (Asahikawa-38), Explanatory
text of the geological map of Japan, 1 :SOOOO.
Geol. Surv. Japan. 66+8pp. (in Japanese withEnglish abstract).
Vereschagin, U. N., Kinasov, V. P., Parakechov, K. V.
and Terehova, G. P. (196S): Illustrated book of theCretaceous fauna from the Northeast USSR. 66
pp., 74 pis. NE Dept. Geol. Nat. Indust. Geol.
Comm. USSR (in Russian).
Woods, H. (1911): A monograph of the Cretaceous
Lamellibranchia of England. vol. 2, part 7,
Palaeontgr. Soc. p. 261-284, pis. 4S -SO.
Yoshida, T. and Kambe, N. (19SS): Ikushumbets-Dake(Sapporo-IS), Explanatory text of the geologicalmap of Japan, 1 :50000. Geol. Surv. Japan, 31 +7pp
(in Japanese with English abstract).

Asahikawa 1l!l.JII, Gono-sawa 1iif)rJ\, Hatonosu i!IW;/~, Horokanai ~:J.mP'J, Ikushumbets ~~5JU,
Ikushumbets-Dake ~~5JUffi, Kamihobets J:.lm5JU, Manji 75,+, Mikasa .=3'):, Obira 'J'f,
Osawa :/It;fo, Oyubari *~~, Pombets 1f5JU, Pombetu (Ponbetu) 1f5JU, Saku iti:~, Sapporo ;tL~, Soashibets ~}S5JU, Takino-sawa it / i'R, Takiyoshi-zawa itsi'R, Tappu ~;ffl, Torii-zawa .!W
Ji!}i'R, Uwajima 'if.;fo,lil" Yezo m~ (x. :/).

B *if)T "" - P .:=. 7 /' J:.$;/J> G~-t" 7.:> Inoceramus tenuistriatus Nagao et Matsumoto v;::'""?~'-C : Inoceramus tenuistriatus Nagao et Matsumoto, 1939 if))JJl:~"'eif)ilc~ . ~~f'i;/J>tJ: IJ ~lit""C~7.:> V;::. t ;/J>;/J>:bGf, rm7i-if)Wf~~v;::'f'i*fj;/J\&:,Gf L tIE L <~m~h n,t.e~' ~ G ~,;/J\~ 7.:> •.:t::. ""('*~~"'ef'i*fjif)fl:t;~JiE;/J> GmGht-:~ <if) fJ* v;::. ""?~ '-CHlJIU~rr~', m{t~if)~~;/J> G~.H~.~~ ::'hGif)M.~b~~-C*fj~~~.Lk • .:tif)J:.""C~*~~~X.~*f~*if)-f:! /""'7':=' 7 /,~if)~':b~7.:> "Inoceramus (I.) tenuistriatus" v;::.""?~'-c.Jt~.H Lt-: • .:tif)M. , .:th G f'i*fj t. f'i~~t!9v;::.IK5JU ~ h7.:> ::. t. ;/J\~ G;/J> t. t.e '? t-:, .:thfH.I' L 6, ~trm:iI! -f:! / ""'7.:=. 7/' J:.$if)#*4v;::,£-?~ '-C~lz: ~ht-:, I. nodai Matsumoto et Tanaka, 1988 v;::.jj'iJ~~h7.:> if)""('ftt.e ~ ';/J> t. ~, ? i".L\-* . Ell'*' if)~~v;::,~~~~ Lt-: ~ '. *fjif)fl:t;~JiEif)JiE~f'illi!H~-t" 7.:> ft:fi;/J>
G T "" - P ::. 7 /' J:.$""(' ~ 7.:> ::. t. f'i~ G;/J>""c ~ 7.:>. A,@]f'ifl:t;~JiEif)m{t~v;::.""?~ '-C if)~:f& '? t-:if) ""('*fjif)J1!;if) ~ ~t!9~ tf:l~lmiJ\J:. rvU:' ::. i ""('mJ 7.:> if);/J>f'iA,~if)WI!JI!l t. L -C~ L -C:to <•!fEE~Z

601

PROCEEDINGS OF THE PALAEONTOLOGICALSOCIETY OF JAPANa 1:tl~4&,;~il;AA137@]{9Uil;;(M988ij:: 6 }J 25 . 26 alWid+1 a lWJl& irf J: I) it-t ~ %~tlJ4&,;it:fiirfO):i1E~~{\: .................................... ~ 5tiiti~· il"l1tl'El*=

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mJ1,!,~MJi\IIJHlJ:i1EJ:.$'T·;-f:/ *il'O)iRJl&1.1' I? ¥Est ~lmycJ1,!,f,fgv.:.~ft ~ m~lill1iXERO)*1rJiltit (~¥In··· .. ···· .... ·· ............ ·.. ilJF"J'ifI.!!lh t.: Leptophloeum V.:. --::> l' c:............... ,J,~ rj[· 3(HlIlii±~~Jl&irf£ Taeniopteris ~v':' --::>l' c: ...... F"JHiiJJl(:t:AA~~Jl&irf£=· -=O):fl!4&,;{t:fiv':'--::>l'C:............ F"JHiiJJl(:t:AA· ;frD~l'f)a1:JIUI:::i1E::IJ:t:iZi'FI$O)1&:Jt1.I:);>. 7*C:fl!4&,;irf.............. ·*{t~T . *H~1jFj.¥~J1,!,E~J1,!,*~#O).1rJ-t)-:/~~irf~m............... 1t~'*)c . t~Hl{$m~l'L!E,ID!:O)~~ . ~~lqjW:{;$:J:t;(),l?f~l?h~tlwi'F~$~~*.TJl&irf£{tm~TO)~.~W~.......................................... *~.'i!;',.@: .
mJ1,!,~113,~tiEjJ$:v.:.5J~;(p-t ~ 'Nm:ofR.0'6 0) !1l1Jf113 C: ~4&,;113 ................................. ~!j!f'ilfJ1;: . lltrHlBg &::ItJ:.ilJ:i1Eit'T·;-f :/*cJl?H)E~ Zdimir c -t 0) tl~4&,;:i1E......... J\*I/fiJIjFj~ . iftilF"Jlllfii'El . *H~1jFj::II::W.@:J:. $ ~ ~*£ N ilssonia ~ 0) ilt~ C: .:t hI? 0)~a1:O)T$:);>.7*Kit-t~~~~*=&J'l,

cuticle·· ........................ ·*~{Jf';:w..

*H~1jFj~~1J!l''*J:!I!.~~a··········································HliR~-

Posidonotis dainellii O)~4&,;:i1EJ:!I!.~J:.O)~a.............................. jf7.k::II::W.@:J:.$~~*ito) i --::>HO)),JtlIHI::Ev':' --::>L 'C:~

J:.$~~*~~Jl&irf J: I) itt±:l-t ~ :fl!4&,;ifflfflXJt>a:- Jf! L'

ilJ $ -= ilJ Jl& 0) =& ¥l. C: lJe0'6113 v.:. --::> L' c:........ ·Hl~JIz ·lltrHlBg&· '8"Hl-~t.:5j'~irfO)mlE .................. *H~1jFj . '8"tliif1i-l'f)tlB~·~~:i1EJJilZK5J';(p-t~J:.$m~~irfJ:l)itt±:l............... **{Jt- . *tt~1jFj

j§j_.~K~ih~~~740):fl!4&,;M.~~W~('Nl!llt5J';(Pv,:,~..-j L' t.:M1L~~iJUN. rfifflfflX5J'~e;v':'--::>l'C:) ............ ilJ_~x· iIDJlj;A· *HiiHIl-t~ Inoceramus uwajimensis O)ittk"·lf'.JII$l'f)

Some inoceramids (Bivalvia) from the Cenomanian(Cretaceous) of japan-N. An interesting new.............. ·1~HlW~ . .l!l!:~I!iZ=

species from Hokkaido...... Matsumoto, T. and Tanaka, K .

~$m~~irf~J:rf~~Jl&irf$·J:.$O)lill1iXERij::~

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(Cretaceous) of japan- V. A world-wide species
Inoceramus pictus Sowerby from japan.................... ·Matsumoto, T.

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w~~+-=i'IiflffilJ?l:i1EJJilZO)~AA-=*1&1iXERitEJl&F'f.............................. 1:ilJ :;iJ

~t$.@:· -t)-/, ~ :/it~~*c~ / ~.:::. 7 :/JtIlo)-{ / ~7 J,. ~ ~ -I Birostrina nipponica (Nagao et

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tkHlmm:l/fiJJl&itJ'l,MERit:Oirf~ C: !1l1Jf4&,; C: O)~i*...... · .... · ............ ·.... ·A}J~1jFj

Gigantic ammonites from the Cretaceous Futaba*::It:i1E::IJO)1&:Jt1.I$~-tlt~a'I1~RERitEirf C: tl~4&,;

A sphenodiscid ammonite acquired rarely from theCretaceous of japan'I1~RER (~¥ID:i1EJ:!I!.~~~a .................... ·*Hi~JI . 1tiR~1lii

Group of Fukushima Prefecture...... Y!atsumoto, T., Nemoto, M. and Suzuki, C.

602···············Matsumoto. T. and Morozumi Y.
Origin and migration of the Asagai-Poronai fauna(Otuka. 1939) in the northwestern Pacific region·············································Honda. Y.

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i1&iiiJ:JH:{f? .l'!. ft.1:i1rf~~(J)~Rlt- rk(f,~llf(J){?rJ.............................. Jli~JJJt1=.

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The first occurrence, of I magotaria (Mammalia :Otariidae) from Japan............ Kohno. N, and Hasegawa. y,~M.~~~~~~~c/*~llfl~.WL~=a1$~JlI Jlf.,9='*~llf.;;r.. T ::z'7~WtlT~)(J)*tVcB':Jm~c.-t-(J)~~

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r /'~M (J) ~*ft.1:it;:: "?

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tltgj5A:;k~.\!;',jitli1&W~ '7 -!l ~ a ":I 7" ............

.............. ·~~t:1iti . :;k~1E1iti
New members approved by the Council Meeting held on June 24,1988.
Ordinary Members:
Aita, Yutaka; Ono, Toshio; Kamiya, Hidetoshi; Yokoi, Takayuki; Ushirogawa Noriko;Niikawa, Isao; Takahashi, Kiyoshi; Suzuki, Makoto; Iwaki, Takako; Takai, Masanaru;
Sasaki, Takuma; Haga, Masakazu; Sasaki, Osamu; Kaneko, Kazuo; Nishida, Noriyuki; Seto
Koji; Chiba, Masarni; Sawada, Hirorni
Withdrawing Members:
Surnitomo Sekiyu Kaihatsu Co., LTD. (patron); Kubo, Chiko; Tatematsu, Yasuo;
Yamamuro, Masurni; Sawada, Yoshio; Shimizu, Hideto; Fujiura, Tsuyoshi.
Deceased Member:
Kuroda, Tokubei (Honary Member, May 15,1987)
ErrataNo. 150,858. Tatsuro MATSUMOTO and Yoshiro MOROZUMI:A sphenodiscid ammonite acquired rarely from the Cretaceous of Japan.
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Transactions and Proceedings of the PalaeontologicalSociety of Japan

New Series No . 151

October 31 , 1988

CONTENTS
TRANSACTIONS
861. KIMURA , Tatsuaki, OHANA, Tamiko and TSUJII, Masanori : Early Jurassic plants inJapan. Part 8. Supplementary description and concluding remarks . . . . . . . . ..... 501·862. SASHIDA, Katsuo and TONISHI , Keiji : Additional note on Upper Permian radiolarian fauna from Itsukaichi, western part of Tokyo Prefecture, central Japan . . .. . 523
863. HORI, Rie: Some characteristic radiolarians from Lower Jurassic bedded cherts of theInuyama area, southwest Japan... . ..... .... . ... .... .. . . . . .... . ... 543

864. HA YAMI, Haru : A Tethyan bivalve, Posidono tis dainellii, from the Lower Jurassic ofwest Japan .... . . . ... . . .. . . . . . . . .. . . .. .. ..... . ... .. . . ....... 564
865. MATSUMOTO , Tatsuro and TANAKA , Keisaku : Some inoceramids (Bivalvia) from the
Cenomanian (Cretaceous) of Japan - IV. An interesting new species from Hokkaido . . . .. . . . . . .. . .. . . . .. .. . ... .. .. . . . . . . . . . . .. . . . . . . . . . .. 570
866. NODA Masayuki: A note on Inoceramus tenuistriatus Nagao et Matsumoto (Bivalvia) from the upper Turonian (Cretaceous) of Japan . . . . .. . .. . . . . . . . . . . . . . 582
PROCEEDINGS. . . . . . . . . .... . . . .. . .. .... . ... .. . . . . ..... . . . ...... 601