ISSN 0031-0204

a ~'1;--i.~T~.-'k- ~z.t

Transactions and Proceedingsof thePalaeontological Society of Japan
New SeriesNo. 119

Palaeontological Society of Japan
September 30, 1980

--

Co-Editors
Associate editor

Itaru HAYAMI and Tsunemasa SAITO
Tomowo OZAWA

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President: Tetsuro HANAI
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Kazuo ASAMA, Kiyotaka CHINZEI, Takashi HAMADA, Tetsuro HANAI,

ltaru HAYAMI, Hisayoshi IGO, Kametoshi KANMERA, Tamio KOTAKA, Tatsuro MATSUMOTO, Ikuwo OBATA, Tsunemasa SAITO, Tsugio SHUTO, Yokichi
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The fossil on the cover is Nipponitella explicata HANZAWA, an aberrant
uncoiled fusulinacean from the Lower Permian Sakamotozawa Formation,southern Kitakami, Northeast Japan.

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Trans. Proc. Palaeont. Soc. Japan, N. S., No. 119, pp. 339-358, pis. 38-40, September 30, 1980

718. EARLY JURASSIC PLANTS IN J AP AN, PART 1*
TATSUAKI KIMURA and MASANORI TSUjIITokyo Gakugei University, Koganei, Tokyo 184

Abstract. This is the first of serial papers on the early Jurassic (Liassic) floras
of Japan. Here we review their geological background and give lists of all recorded
species, together with some revisions of taxonomic names. Furthermore, we describe
Equisetites iwamuroensis KIMURA, E. mori.gumpeii KI:VILRA & TSUJII sp. nov., E.
nipponicus KIl\Il.oRA & T5l;JII sp. nov., E. sp. A, E. sp. Band E. sp. C.

description is completed.

Foreword
Previous works

In japan, Lower jurassic (Liassic) plantbearing strata are the Higashinagano
Formation of Yamaguchi Prefecture, theYamaoku Formation of Okayama Prefecture, the Kuruma Group extending overToyama, Niigata and Nagano Prefectures,the Iwamuro Formation of Gumma Prefecture, and the Shizugawa Group of
Miyagi Prefecture. Their localities areshown in Fig. l.
In this paper we review the localities
and horizons of Lower jurassic plantbearing beds in this country, giving listsof all recorded species with some nomenclatorial revisions. Furthermore, we describe specimens of Equisetites, most ofwhich were collected by us from theKuruma Group in 1976-79 and by Mr. N.
SASAKI from the Iwamuro Formation in
1975-77, with the help of Mr. A. KOBAYASH I and many students of Tokyo
Gakugei University.
The rich flora of the Kuruma Group
includes most species which have been
known from the Lower jurassic of japan.
We intend to discuss the relation withseveral floras of other regions, after their

1) Fossil plants of the Kuruma GroupOn the basis of KRYSHTOFOVICH'S
identification, Y AGI (1918) recorded thefollowing species from Tsuchizawa (orTunzawa), Nagano Prefecture; Equisetitessp., Clathopteris sp., Cladophlebis denticulata (BRONGNIART), Ginkgo sp., Czekanowskia sp., Phoenicopsis angustifolia HEER
forma media KRASSER and Podozamites
lanceolatus (LINDLEY & HUTTON). This
was the first record of the fossil plantsfrom the Kuruma Group, but no descriptions were given.
KOBAYASHI (1927) listed Equisetites
sarrani ZEILLER, Cladophlebis haiburnensis(LINDLEY & HUTTON), C. raciborskii
ZEILLER, Ptilophyllum sp., Taeniopteris
cfr. virgulata ZEILLER and T. sp. from
Tsuchizawa, and Dictyophyllum sp. andPagiophyllum sp. from the Dairagawa
area.
OISHI (1931) revised YAGI'S Cladophlebis
denticulata, Ginkgo sp., Czekanowskia sp.
and Phoenicopsis angustifolia forma media
as Cladophlebis raciborskii, Ginkgoites
sibirica (HEER), Czekanowskia rigida
HEER and Phoenicopsis sp., and KOBAYASHI'S Cladophlebis haiburnensis, Ptilo-* Received Dec. 25, 1979; read Oct. 20, 1979
at Nagoya.
339

340

l'atsuaki KIMURA and l1tlasanori TSUJI!
(NATHORST).
Dairagawa locality; Dictyophyllum sp.
and Elatocladus sp.
OISHI (1931b) revised his W oodwardites

microlobus, Cladophlebis al'gutula, C.
raciborskii and Ginllgoites sibirica as
Thaumatopteris schenki NATHORST, Cladophlebis sp. B, C. dr. raciborskii ZEILLER
and Ginkgoites digitata (BRONGNIART)
var. huttoni SEWARD, respectively. He

Fig. 1. Distribution of the early Jurassic
plant-bearing formations in Japan.

phyllum sp., Taeniopteris dr. virgulata
and Pagiophyllum sp., as Cladophlebis
raciborskii ZEILLER, Pterophyllum propinquumGoEPPERT,Marattiopsismuensteri(GOEPPERT) and Elatocladus sp., respectively. He listed the following species:
Tsuchizawa locality;
Equisetites sp.,
Neocalamites hoerensis (SCHIMPER), Clathropteris sp., Marattiopsis muensteri(GOEPPERT), Cladophlebis argutula (HEER),
C. denticulata (BRONGNIART), c. haiburnensis (LINDLEY & HUTTON), C. raciborskii
ZEILLER, Pterophyllum jaegeri BRONGNIART, P. propinquum GOEPPERT, Ginkgoites
sibirica (HEER), Czekanowskia rigida HEER,
Phoenicopsis? sp., Pityophyllum longifolium (NATHORST), Podozamites lanceolatus (LINDLEY & HUTTON) and Carpolithessp.
Shimodera locality; Equisetites sp., Czekanowskia rigida HEER and Podozamites
lanceolatus (LINDLEY & HUTTON).
Kuruma locality; Equisetites sp., W oodwardites micro lobus SCHENK, Cladophlebis
denticulata (BRONGNIART), Czekanowskia
rigida HEER and Pityophyllum longifolium

described all of these species. This is
the first description of the fossil plantsfrom the Kuruma Group.
Moreover, OISHI (1932) revised his
Cladophlebis sp. B as C. pseudodelicatula
OISHI, and OISHI & TAKAHASHI (1936)
revised OISHI'S Cladophlebis cfr. raciborskii
as C. raciborskii forma integra OISHI &TAKAHASHI.
In addition, OISHI (1940) revised his
Thaumatopteris schenki as ? T. elongata
OISHI, and described the following species:
Neiridani locality in the Dairagawa area;
Todites
goeppertianus(MUENSTER)KRASSER,
Clathropteris
meniscoides
BRONGNIART, Sagenopteris nilssoniana(BRONGNIART) WARD and Nilssonia orientalis HEER.
Kuruma locality; Sagenopteris nilssoniana(BRONGNIART) WARD and Cfr. Nilssonia
tenuicaulis (PHILLIPS) FOX-STRANGW AYS.
K. KOBAYASHI (1948) listed the following species from Tsuchizawa, Kuruma
and Komyoshita localities: Equisetites sp.,
Neocalamites hoerensis (SCHIMPER), Annulariopsis inopinata ZEILLER, Todites
roesserti (PRESL), Marattiopsis muensteri(GOEPPERT), Clathropteris meniscoides
BRONGNIART,
Thaumatopteris schenki
NATHORST, Hausmannia nariwaensis OISHI,
Cladophlebis denticulata (BRONGNIART),c. haiburnensis (LINDLEY & HUTTON), C.
nebbensis (BRONGNIART), C. raciborskii
ZEILLER, Nilssonia sp., Taeniopteris sp.,
Ginkgoites digitata (BRONGNIART) var.
huttoni SEWARD, Baiera dr. muensteriana

718.

Early JU1"Ussic plants(PRESL), Czekanowskia rigida HEER,
Phoenicopsis sp., Pityophyllum longifolium(NATHORST),
Podozamites lanceolatus(LINDLEY & HUTTON), Carpolithes sp.
Based on SASAI'S collection from the
Kotaki Coal-Field, Niigata Prefecture,
KIMURA (1959b) described the following
species: Equisetites sp., Neocalamites
carre rei (ZEILLER) HALLE, N. hoerensis(SCHIMPER) HALLE, N. sp., Dictyophyllum?
sp., Cladophlebis denticulata(BRONGNIART),
C. haiburnensis (LINDLEY & HUTTON), C.
raciborskii ZEILLER, Pterophyllum propinquum GOEPPERT, Ginkgoites digitata(BRONGNIART) var. huttoni SEWARD, G.
sp., Czekanowsllia sp., Phoenicopsis sp.,
Pityophyllum longifolium (NATHORST),
Podozamites lanceolatus (LINDLEY &HUTTON), P. sp. dr. griesbachi SEWARD,
Taelliopteris sp.
Fossil plants of the Iwamuro Formation
KIMURA (1952) found many fossil plants
at Iwamuro of Gumma Prefecture andnamed the plant-bearing strata the Iwamuro
Formation. Subsequently the following
species were described by KIMURA (1959a) :Equisetites iwamuroensis KIMURA, Neocalamites hoerensis (SCHIMPER), Coniopterissp., Clathropteris? sp., Thaumatopteriselongata OISHI, T. nipponica OISHI,
Hausmannia (Protorhipis) sp., Cladophlebis
clavata KIMURA, C. denticulata (BRONGNIART), C. fastuosa KIMURA, C. haiburnensis (LINDLEY & HUTTON), C. raciborskii
ZEILLER, C. raciborskii ZEILLER forma
integra OISHI & TAKAHASHI, C. spp. (A,B), Nilssonia orientalis HEER, N. sp.,
Ctenis ? sp., Anomozamites sp., Otozamites
fujimotoi KIMURA, Pterophyllum spp. (A,B), Baiera? sp., Ginkgoites? sp., Czekanowskia rigida HEER, Pityophyllum(Pityocladus) sp., Podozamites lanceolatus(LINDLEY & HUTTON), P. sp., Swedenborgia
cryptomerioides NATHORST, Taeniopteris
gracilis KIMURA, T. sp. dr. nabaensis
2)

341

OISHI, T. spp. (B, C).
3)

Fossil plants of the Yamaoku Formation
KONISHI (1954) listed the following
species: Equisetites yamadai KONISHI (MS),Neocalamites? sp., Marattiopsis sp.,
Todites wiliiamsoni(BRONGNIART) SEWARD,
Clathropteris meniscoides BRONGNIART,
Cladophlebis denticulata (BRONGNIART),
C. haiburnensis (LINDLEY & HUTTON), C.
gigantea OISHI, C. raciborskii ZEILLER,
Ctenis sp., Taeniopteris sp., Pityophyllum
n. sp. KONISHI (MS), P. sp., Podozamites
lanceolatus (LINDLEY & HUTTON).
Fossil plants of the Higashinagano
Formation and the Shizugawa Group
Only two species, Nilssonia brevis
BRONGNIART (OISHI, 1940) and doubtful
Brachyphyllum expansum (STERNBERG)(TAKAHASHI, 1957, '59) have been known
from the Higashinagano Formation, andBaiera? sp. (YOKOYAMA, 1904) and awood species, Dadoxylon (A raucarioxylon)
sidugawaense SHIMAKURA (SHIMAKURA,
1937) have been known from the Shizugawa Group together with some indeterminable leaf-fragments.
4)

Geology
1)

Kuruma Group
This Group is distributed in the steep
mountainous area extending over Toyama,
Niigata and Nagano Prefectures in the
Inner Zone of Central Japan. The western
main distribution along the Dairagawa
and its tributaries was stratigraphicallystudied by KOBA YASHI et al. (1957).
According to them, the group is divided
into the following formations in downward
sequence.
Kurobishiyama Formation; conglomerate bearing Podozamites ? sp. and small bivalves.
--unconformity-Tc~ts'Ualc'i342

K IMU RA and Jlt[c~sano?·i T SUj II

Lillill Mizukamidani F(Km) ~ Palaeozoic limestones~ Otakidani F .( Ko).... Palaeoz oic Group[[ill

Shinadani F.(Ks)~ Kurobishiyama F.

~ Teradani F.(Kt )EJ Negoya F.(Kn )~~ Kitamatadani F.(Kk)F='l•~ Jogodani F.(Kj)

Undivided~~ Upper alternations (KrL)

II Alternations(Kn, KrJ)

~ Tertiary Group

,
I III
1111

Schists

II Metagabbro.;. .rr, Serpentine~

G Granodiorite
Porphyrite
lli21
"
,.,i

.... ... Dyke rocks~~ Tuff"CJ Ryolite~ Andesite

F='lt::::J Lower alternations (Kn)Fig . 2. Geological map of the Kuruma Group (redrawn from K OI3A YAS III et ai. , 1957 ;e = localities of fossil pl ants) .

718. Early Jumssic plants:\1izukamidani Formation (Km) ; conglomerates
and sandstones with subordinate shales(+ 2000 m thick) ; barren of fossils.
Otakidani Formation (Ko); sandy shale, withsubordinate thin sandstones-conglomerates
of marine origin (850 m thick) ; ammonites
indicating Upper Toarcian.
Shinadani Formation (Ks); sandstones andshales (+ 700 m thick) , bearing littoralshells and plants above, and marine shells
below.
Teradani Formation (Kt); sandy shale (600 m
thick) ; ammonites indicating Upper Pliensbachian.
Negoya Formation (Kn); alternation of sandstone and shale, bearing littoral shells andplants above," and sandstone beari~g littoralshells below (total 1600 m thick).
Kitamatadani Formation (Kk); alternation ofsandstone and shale above, shale middle,
and sandstone below (total 2000 m thick),all bearing littoral shells.
Jogodani Formation (Kj); conglomerates andsandstones with thin shales above and basal
conglomerate ( + 700 m thick); barren offossils.
--unconformity-Sangun-type schists

The southeastern subordinate distribution
including several classical localities offossil plants, was also studied by KOBAY ASHI et al. (1957).
According to them,
the group was divided into the following
members in downward sequence.
Upper alternations of sandstone and conglomerate (Kr.,); barren of fossils.
Alternations of sandstone and shale (Kr,,);(+400 m thick) ; bearing littoral shells andplants.
Alternations of sandstone and shale (Kr2);
bearing plants (including Tsuchizawa,
Shimodera and Kuruma localities).
Lower alternations of sandstone and conglomerate (Kr1); (500 m thick).
--supposed unconformity-Palaeozoic formations

Unfortunately, the stratigraphical relation between this southeastern section

343

and the section III the main area is unknown.
The northeastern subordinate distribution including the Kotaki Coal-Field
was studied by SASA!. The detailed
stratigraphy and the occurrence of plants
were shown by KIMURA (1959b). The
stratigraphical relation between this area
and the main area is uncertain. Fig. 2
shows the localities of fossil plants on
the geological map redrawn from KOBAYASH! et al. (1957).
2) Iwamuro .Formation
This formation is exposed at the small
area along the middle course of Katashinagawa, in the Inner Zone of Northeast
Japan. Its detailed stratigraphy and theoccurrence of fossil plants were alreadyshown by KIMURA (1952).
Acknow ledgements

We record here our cordial thanks toProfessor Emeritus Thomas M. HARRIS,
F. R. S. of the University of Reading,England for his critical reading of thismanuscript and his valuable suggestions
during the course of this study.
Our thanks are particularly due to Mr.
Gumpei MORI, Mr. Noriyuki SASAKI, Mr.
Akihiro KOBA Y ASH! and students of Tokyo
Gakugei University for their kind help incollecting fossil plants from the Iwamuro
Formation and the Kuruma Group.
Acknowledgements are extended to the
Educational Committee of Asahi-machi,
Toyama Prefecture for giving us thefacilities of lodging for a long time. We
also give our thanks to Miss Tamiko
OHANA of Tokyo Gakugei University forher kind help in drawing the text-figures.
Systematic description

Pteridophyta

344

Tatsuaki KIMURA and Masanori TSUJII
Equisetales

In our collection, two genera, Equisetites
and Neocalamites were recognized in this
Neocalamites species will beorder.
described later.
Genus Equisetites STERNBERG, 1833: 43
Key to the early Jurassic Equisetites
species in Japan
They are conveniently distinguished by
the size of erect vegetative stems andthe number of leaf-segments.
1. Erect vegetative stem large in size, morethan 7 cm in diameter ... . E. mori-gumpeii
1'. Erect vegetative stem medium in size, lessthan 5 cm wide (3.2 cm in diameter) .... 2
2. The number of leaf-segments, less than 28. .. .. .... .. .. .. .. .. .. ... E. iwamuroensis
2'. The number of leaf-segments, more than
40 ...................................... 3
3. The number of leaf-segments, less than 48............................ E. nipponicus
3'. The number of leaf-segments, 52-74 ..... .
................................ E. sp. A

Besides the above, there are two little
known species: E. sp. B is based only arhizome and E. sp. C is based on a large
nodal diaphragm.
Equisetites iwamuroensis KIMURA
PI. 38, Figs. 1-9; PI. 39, Figs. 1--6;
PI. 40, Figs. 1-2; Text-figs. la-kEquisetites sp.: OISHI, 1931b, p. 228, pI. 16,
fig. 1 (Tsuchizawa and Shimodera)
Equisetites iwamuroensis KIMCRA: KI:VIURA,
1959a, p. 6, pI. 1, figs. 1-6; pI. 12, figs. 1,
10; text-figs. 1-2 (Iwamuro).
Material: Lectotype; A-3051. Paralectotypes; A-I036, 2058, 2070, 3056, 3072, 3075,
3076, 3081, 3088, 3088C, 3093, 4071, 7577,7582,
7584, 75183, 7901A, 79018, 7902, Kr-006,

009, 011, 013, 020, 021, 025, 027, 028 and 23
additional sp~cimens (A; from the Iwamuro
Formation, Kr-; from the southeastern subordinate distribution of Kuruma Group).
Stratum typicum: Middle member of the Iwamuro Formation. Locus typicus: Iwamuro,
Shirasawa-mura, Tone-gun, Gumma Prefecture. Derivatio nominis: After the locality,
Iwamuro where the original specimens werecollected.

Emended diagnosis: Erect vegetative
stem simple, unbranched, 35 mm wide
below, but suddenly contracted at base,narrowing gradually upwards, about 10
mm wide at an apical part. Lower nodes
crowded and upper ones at intervals of36",78 mm, both without bulges. Internode typically 78 mm long and 20 mm
wide, with smooth surface, but marked
with numerous pits, 125 pmx75 pm, 125
pm X 100 pm in size. When partly or
fully decorticated surface showing longitudinal ridges as numerous as leaf-segments.
Leaf-sheath 12",25 mm long,
composed of 24",28 raised leaf-segments(typically 24), number reduced to 22 on
the upper nodes, slightly swollen into
cup-like form; lower 80% of leaves unitedby flanges to form a sheath, upper 20%
forming free teeth. Commissural flanges
nearly truncate above, narrowing downwards, forming commissural furrows
continued for about 0.5"'1 cm below thenode. Leaf-segments 1",2 mm wide below,
abruptly thickened in texture at the topof coherent sheath. Coherent leaf-segments covered with crowded fine pits
similar in size to those on the internodes.
Free teeth 2.5",4 mm long, elongatetriangular in form, rigid and thickened
in texture, often with reflexed margins;
those on the lower nodes tapering toacuminate apex and those on the upper
nodes gradually tapering to acicular apex;
mostly broken off leaving its thickened
and trapezoid base at upper end of

718.

Early Jurassic plants

coherent sheath; midrib not visible. Leafsheath on upper nodes similar in form tolower ones but smaller in all their parts.
Nodal diaphragm often rotated by compression but mostly not displaced up or
down, sometimes isolated; circular infront view, 3'"'-'27 mm in diameter, surface
finely granular, with a single outer ringof tubercles about 2 mm from the edge;
tubercles dome-shaped, twice as numerous
as leaf-segments. Cone terminal on aslender shoot, 2.7 mm wide. Uppermost
leaf-sheath composed of about 10 segments,
lrvl0 mm connected above by flanges,
free teeth missing. Nodal diaphragmnormal, rotated but very small, just over
1 mm wide.
Next leaf-sheath below
composed of more numerous but muchnarrower leaf-segments about 0.25 mm
wide. Cone (unexpanded) about 6 mm
wide, barely 4 mm long, showing 3 whorlsof sporangiophore heads, heads hexagonal
and in contact. In surface view heads(in disintegrated cone) up to 2 mm wide,
marginal regions raised, central partsunken with 6'"'-'7 circular marks (sporangia), inner surface showing end of acentral stalk. Rhizome sparsely branched,
4'"'-'14 mm wide with comparatively longinternode; internodes smooth but often
showing broad and irregular ridges(thought to have been produced bycompression); leaf-sheath similar in form
to that of erect vegetative stem, with 24
closely appressed leaf-segments, without
pits both on internodes and leaf-sheath.
(Root unknown.)
Distribution and occurrence:
Equisetites iwamuroensis is abundant in the
middle member of the Iwamuro Formationand the Alternation of sandstone andshale (Kr 2) in the southeastern subordinate
distribution of Kuruma Group at Tsuchizawa and Shimodera localities, where it is
the commonest fossil and no otherEquisetites species has been found.

345

Most specimens are broken and flattened
stems and rhizomes. Accordingly it isconsidered that they are not in the site of
growth.
Observations: PI. 38, Fig. 1 shows thebase of an erect vegetative stem whichis from 3.4 em wide (2.2 em in diameter)
above to 1.8 em wide (1.2 em in diameter)
below for the length of 4.8 em; its nodes
are crowded at intervals of 1.0'"'-'1.8 em.
It may represent the basal part of anerect stem below water surface. This
would explain the absense of pits (stomata).
No bulges were found at the nodal region.
The stem often shows a distinct swellingat the node. This may be due at least inpart to the existence of transverse nodal
diaphragms which resisted compression.
Lower halves of leaf-sheaths and commissural furrows are well preserved but
upper halves of leaf-sheaths are all lost
together with their free-teeth.
Three internodes of typical width are
represented by the specimen shown in PI.
38, Fig. 2 (Text-fig. la; lectotype), which isstrongly compressed. Similar specimens
are shown in PI. 39, Fig. I (Text-fig. lb)
and Text-fig. Ie. Two nodal diaphragms
are marked with arrows in Text-fig. la.
They have rotated but are at their
original levels. The upper is 0.9 em indiameter, the lower 1.05 em, both occupy
about 70% of both nodal diameters. A
similar specimen is shown in PI. 40, Fig. I(Text-fig. Ie). In this specimen the freeteeth are missing, but the sheath 2 emlong is composed of about 22'"'-'28
segments. Leaf-segments in a leaf-sheath
alternate with those of the nodes immediately above and below. Commissuralflanges connecting the adjacent leafsegments are nearly truncate above, andthe two flanges together are narrower
than the leaf-segments at the top of leafsheath and taper to a point downwards.
Below the node they are continued as

Tatsuaki KIMURA and Masanori TsujIJ

346

commissural furrows for about 1 cm (PI.
38, Fig. 5 and Text-fig. ld, PI. 39, Fig. 2).
Free-teeth are acuminate (Text-figs. lc,
Id and Ie) or acicular (PI. 38, Fig. 4 andText-fig. If) in form, 0.6 cm long (Text-fig.
Ic), 0.45 cm (Text-fig. If) and 0.25 cm (PI.
38, Fig. 5 and Text-fig. ld), often missing
leaving their trapezoid. bases thickened
especially at the upper edges as typicallyshown in Text-figs; la-c.
PI. 38, Fig. 3 shows a slender erectvegetative stem compressed obliquely tothe bedding plane. Pi. 38, Figs. 6 and 7
show leaf-sheaths compressed obliquely.
The surface of internodes is smoothapart from the fine pits, but on their

mmn
"

~-

i," ')

decorticated surface there are weaklongitudinal ridges which are twice as
numerous as leaf-segments as partly
shown in Text-fig. lb. These ridges are
not thick strand as in a calamite pithcast, but mere corrugations in an evenly
thin film of coaly material. This is anevidence that they had very little woody
tissue, probably metaxylem strands.
There are small pits on the surface ofinternodes and the abaxial surface of leafsheaths in aerial vegetative stem. Thesepits are longitudinally oriented, 64 per
mm 2 on leaf-sheath and 19 per mm 2 oninternode in density, as shown in Textfig. 19. These pits are not recognized onr----1lcm!i!I~:\

1111

l ..~- ..-( '\,i

ITIli1111i1:11flil\\
1b
2cm

1,

\ ....../'li'l\

lcm

I

2cm

L---J

1J"

I '~~

19
lcm

~.
l~HHHffr/~/.~...

1c
2cm

/

lcm

L...-...J

li

\

1h

718.

Early Jurassic plants

the internodes and the leaf-sheaths ofrhizomes and lower parts of stems thought
to have been below water surface. Pits
are also invisible on the free-teeth.
Besides rotated nodal diaphragm instem, there are several isolated nodal
diaphragms of various size as shown in
PI. 38, Figs. 8 and 9 (Text-fig. 2i), and PI.
39, Fig. 3 (Text-fig. Ih). PI. 39, Fig. 4 shows
the underside of a nodal region.
PI. 40, Fig. 2 shows a detached cone, thedetail of which is shown in Text-fig. Ij.
PI. 39, Fig. 6 shows crushed cones, in which
sporangiophores are scattered. Rhizomes
as shown in PI. 39, Fig. 5 (Text-fig. lk) arefrequent.
Comparison:
In his monographicalstudy dealing with Equisetacean plants inJapan and adjacent areas, the late Professor KON'NO (1962) described several
new Equisetites species; Equisetites
asaensis, E. (Equisetostachys) bracteosus,

347

E. minensis, E. nagatensis, E. naitoi, E.
naitoi subsp. minor, E. takahashii and E.
takaianus from the Carnic formations III
Yamaguchi Prefecture, E. nariwaensis
from the Noric Nariwa Group in Okayama
Prefecture, E. koreanicus from the Lower
Daedong Group (Upper Triassic in
KIMURA's opinion), North Korea and E.
paotensis from the Lower Jurassic of
Neimung, North China.
Among these, Equisetites naitoi, E.
naitoi subsp. minor, E. nariwae71sis, E.
koreanicus and E. paotensis differ from
E. iwamuroensis in having branched aerial
stems.
It seems to be true in the modern
species of Equisetum and. in the better
known fossil species of Equisetites (orEquisetum) that most stems have a fairly
constant number of leaf-segments in theirleaf-sheath. So if we have enough specimens to show what is normal, the number

Text·figs. la-j. Equisetites iwamuroensis KI:VIURA.
la. Compressed stem showing two leaf·sheaths with broken leaf·segments and two rotated nodal
diaphragms. Redrawn more in detail from the lectotype (A-3051) formerly illustrated by
KIMURA (1959a, pI. 1, fig. 1 and text·fig. 1; both were upside down), shown also in PI. 38,
Fig. 2.
lb. A part of erect stem showing longitudinal striations on the decorticated surface of an inter·
node. An arrow indicates the position of nodal diaphragm represented by a prominent ridge.
Redrawn more in detail from A-2058 formerly illustrated by KI~'il'RA (1959a, pI. 1, fig. 2
which was upside down), shown also in PI. 39, Fig. 1.
lc. A broken leaf·sheath on which two free·teeth are still retained. Drawn partly from A-7584.
1d. A part of small·sized erect stem with two internodes. Free-teeth are all preserved. An
arrow indicates the position of nodal diaphragm. Drawn from Kr-021, shown also in PI. 38,
Fig. 5.
Ie. A leaf-sheath of similar size to 1d, with a rotated and contorted nodal diaphragm whichappears to be displaced downwards. The bordered line between free-tooth and its base isindistinct. Drawn from Kr--013, shown also in PI. 40, Fig. 1.
If. Showing a leaf-sheath. The dotted line indicates the position of nodal diaphragm. Drawnfrom Kr-027, shown also in PI. 38, Fig. 4.
Ig. D;!tails of leaf-segments, commissural flanges and the distributional patterns of pits both onleaf-sheath and internode. Drawn partly from If.
lh. The largest isolated nodal diaphragm. An arrow shows a vertically compressed leaf-sheath.
Drawn from A-1036.
Ii. Medium-sized isolated nodal diaphragm. Drawn from A-3093, shown also in PI. 38, Fig. 9.
lj. A small-sized cone supported by an erect stem. An arrow indicates the position of a nodal
diaphragm. Drawn from A-7901B, shown also in PI. 40, Fig. 2.

348

Tatsuaki KIMURA and .Masanori TSUJII

seems to constitute a specific character.
Thus Equisetites iwamuroensis with 24",
28 leaf-segments differs from KON'NO'S
species, E. asaensis (with 12",14), E.
minensis (with 12",14), E. nagatensis (with16",20) and E. takahashii (with 14",16).
Equisetites iwamuroensis also differs from
E. takaianus with sparsely branched or
unbranched erect vegetative stems, because,
according to KON'NO, the number of leafsegments of E. takaianus is said to beless than 16.
In addition, we have Equisetites multidentatlls originally described by OISHI(1932) from the Nariwa Group. Equisetites
iwamuroensis is safely distinguishable
from OISHI's species, because in OISHI'S
species the number of leaf-segments, as
its specific name indicates, is over 80.
Equisetites (Equisetostachys) bracteosus
KON'NO is quite different from the present
species. It is a large cone with alternating whorls of sporangiophores and bracts,in this respect differing generically from
Equisetllm. But below the cone the stem
has leaf-sheaths of the Equisetum-type.
Thus no similar species with Equisetites
iwamlll'oensis has so far been known inJapan.
In dimensions, erect vegetative stems of
Eqllisetites izeamuroensis resemble thoserecorded under the name of E. ferganensis SEWARD (SEWARD, 1907, p. 17, pI. 2,
figs. 25-29; 1911, p. 35, pI. 1, figs. 5-8;
1912, p.4, pI. 1, figs. 2-14, 19; KAWASAKI,
1939, p. 9, pI. 1, figs. 4, 5; pI. 2, figs. 6-8;
text-fig. 1), of E. dr. lateralis (PHILLIPS)MORRIS (SZE, 1931, '33) and of E. sp.
(Y ABE & OISHI, 1933) from the older
Mesozoic of Asia, but these are different
from E. iwamuroensis first in their wheellike nodal diaphragms.
Equisetites iwamurensis has erect stemsof similar width to E. sarrani ZEILLER(ZEILLER, 1903, p. 144, pI. 39, figs. 1-3)
from the Upper Triassic of Hongay Coal-

Field, North Viet-Nam, but E. sarrani has
not more than 20 leaf-segments. KOBAYASHI'S Eqllisetites sarrani (1927) from
Tsuchizawa, may belong to E. iwamuroensis.
In the number of leaf-segments and thestructure of nodal diaphragms, Equisetites
iwamuroensis is similar to the European
species, E. scanicus (STERNBERG) HALLE(HALLE, 1908, p. 22, pI. 6; pI. 7; pI. 8,
figs. 1-5; pI. 9, figs. 16-17) and the Indianspecies, E. rajmahalensis (OLDHAM &MORRIS) FEISTMANTEL (OLDHAM &MORRIS, 1863 ; FEISTMANTEL, 1877 ; SAHNI& RAO, 1933; SURANGE, 1966; BOSE &SAH, 1968). However, Equisetites scanicus
is much larger in size than E. iwamuroensis, and E. mjmahalensis appears to be
distinct in having longer and keeledfree-teeth and longer and wheel-liketubercles on the nodal diaphragm.
A very large number of Equisetites(or Equisetum) species have been describedfrom various regions of the world. Of
these we consider only a few species are
similar to E. iwamuroensis in the following
respects: Aerial stems unbranched, commonly about 2",3 cm wide. Leaf-sheath
composed of about 24 segments, segments
often about 2 cm long and terminating in
narrow teeth about 3 cm long. Commissural franges truncate above, narrowing
and vanishing below the node. Nodal
diaphragm robust, often rotating, surface
granular, with a marginal ring of slightly
elongated tubercles. The following aresomewhat similar: Equisetites asiaticus
PRYNADA (in TESLENKO, 1970) and E.
laevis HALLE (HALLE, 1908; LUNDBLAD,
1950; HARRIS, 1926, '31). But Equisetites
iwamuroensis is distinguished from E.
asiaticus by having shorter tubercles on
the nodal diaphragm, and from E. laevis
by its rather narrower aerial stems andshorter free-teeth.

718.

Early Jurassic plants

Eqllisetites mori-gllmpeii KIMURA and

TSUJII sp. nov.
Text·figs. 2a-c
Material: Holotype; KS-OOI (KS-; from theStratum typicum:
Shinadani Formation).
Lower member of the Shinadani Formation,
Kuruma Group. Locus typicus: At the uppercourse of Shinadani, Omi·machi, Nishi-Kubikigun, Niigata Prefecture. Derivatio nominis:
The specific name is dedicated to Mr. Gumpei
MORI who vigorously cooperated with us incollecting fossil plants from the Kuruma Group.

Diagnosis: Stems preserved erect inposition of growth, diameter up to 81 mm
below but tapered upwards, length exceeding 1 m ; unbranched; nodes closely placed
below. Surface of internodes mainlysmooth but with striations corresponding
to leaf-teeth just above node. Total
number of leaf-segments in sheath typically 114; leaf-sheath 0.5 cm long, appressed; commissural flanges narrower
rapidly below and not extended bygrooves onto internode; free-teeth unknown (broken off at top of leaf-sheath).
Nodal diaphragm not known in surface
view but nodal part of stem robust
enough to form a well marked ridge.
Distribution and occurrence:This
species occurs as a crowded fossil forest
in the sandstone bed of the Lower
member of Shinadani Formation at thenortheastern corner of its distribution.
Unfortunately we have not succeeded torestore this Equisetites forest, because of
the limited exposures. The occurrenceof this species seems to be restricted tothe above mentioned locality where noother Equisetites species have been found.
Observations: Equisetites mori-gumpeii
is locally abundant, but no specimen isperfect. So it is impossible to show thespecimens clear by photographic illustration.
Text-fig. 2a shows a part of erect349

vegetative stem in lateral view on which
the above diagnosis is mainly based. The
arrows indicate the position of robust
nodal diaphragms. Apart from the fallen
free-teeth, the leaf-sheath is low in height,
0.5 cm high and appressed to the stem.
Leaf-segments are about 114 in number,
3.5--",4 mm wide at the base and 3 mm
wide at the tip of appressed part, andcoherent by sunken wedge-shaped commissural flanges, 1.5 mm wide at the tip.
The commissural flange does not pass into
a commissural furrow (Text-fig. 2b) whichis commonly represented in other
Eqllisetites species in Japan.
The fallen free-teeth left the thickened
and semi-circular bases at the tip ofappressed leaf-segment just below the
nodal diaphragm as shown in Text-fig.
2b, so there are double angular brims
around a nodal region; one above is due
to a nodal diaphragm itself and anotherbelow due to a row caused by the
thickened free-tooth bases as shown in
Text-fig. 2c in side view. The longitudinal
stnatlOn on the decorticated surface
extends down to the nodal diaphragmbrim to hide behind the appressed partof leaf-segment and its number corresponds
to that of leaf-segment as shown in Textfig. 2b. It is uncertain whether the leafsegments of one internode do alternatewith those of the internode immediately
above and below or not.
Comparison: Equisetites mori-gllmpeii
is characterized by its large-sized erectvegetative stem, low leaf-sheath consistingof about 114 leaf-segments, and by thejunction between free-teeth and appressedleaf segments which lies just below theangular brim caused by the nodal diaphragms. Then it is safely distinguishedfrom the known Eqllisetites species inJapan including Equisetites species described here.
Equisetites beani (BUNBURY) SEWARD,

350'l'ats~wki

KIMURA (mel Nlasanori 'l'SUJII

a n im perfect ly k no w n, species from the
Bajocian of England has a more strong ly
striated interior, the rid ge being closer
than in E. mOl'i-gumpeii. Its leaf-sheathis un known but there are somet imes commissural furrows passing do w n from thenode (see HARRIS, 1961). Its size issimilar.
Equise liles al'enaceus BRONGNIART, an
Upper Triassic species has much larger
stems (80",160 mm w ide).
Equise tum
columnare BRONGNIART of simi la r size
has a longer leaf-sheath.
Thus Equise tites 11vori-gumpeii, a lthough
it is not fu ll y knoviTn, IS dist in ct andwou ld be regarded as new to sc ience.

Equisetites l1 ipponicus K IMURA and
T SU Jll sp. no v.
PI. 38, F ig . 10; PI. 39, Figs. 7- 9;
PI. 40, F igs . 3- 6 ; Text ·figs. 3a - g

Equiset ites sp. :Coal -F ield ) .

KI ~ Il"I~ A , 1959b, p. 66 (Kotaki

Mat erial: Holotype; NN W- 800. Parat ypes;
NN W- 22Ll, 322, 456, 466, 792, 793, 796, 798,
811, NEE- 128, 340 (aeria l and submergedstems) , NN W - 814 (noda l diaphragm), NN W808, NEE- 284 (rhi zo mes) an d man y ot her leaf -

12em

4c

\

3c

4 em

~_ _- L_ _~I

1em

~

'2em

4a
12 em

'--_...1.--_.....

- 2b )<
2c
c

718.

Early J~wassic plants

sheath fragments (NNW--; from the NishiNeiridani, and NEE-; Higashi-Neiridani).
Stratum typicum: Negoya Formation, Kuruma
Group. Locus typicus: At the middle courseof the Neiridani Valley, .Asahi-machi, Toyama
Prefecture. Derivatio nominis: The specificname is derived from 'Nippon' meaning Japanin Japanese.

Diagnosis: Erect vegetative stem unbranched, basal part thicker, 3.6 cm wide351

but suddenly contracted at base, andgradually narrowing upwards, 9 mm wideat the apical part. Lower nodes crowded,
upper ones typically at 7 cm, both withoutbulges. Nodes usually slightly swollen.
Internodes smooth, 12 mm X 24 mm, 30 mm
x29mm, 76 mmx36 mm to 70mmx9mm,
without internal or external ribs or
angles. Lower sheath appressed to stem,with 40'""'48 (typically 48) segments in the

Text-fig. 1k. Equisetites iwamuroensis KIMURA. Showing a part of rhizome. Internodes are
generally longitudinally wrinkled as indicated by the dotted lines. Drawn from Kr-006,
shown also in PI. 39, Fig. 5.
Text-figs. 2a-c. Equisetites mori-gumpeii KIMURA and TsuJI! sp. nov.
2a. A part of thick erect stem, standing in the site of growth. The arrows indicate the positionof nodal diaphragms. Drawn from KS-OOI (holotype).
2b. Front view of a leaf-sheath. Note that commissural furrows are absent on the internodesurface. c; semi-circular free-tooth-base of which margin is thickened. d; indicating theposition of a nodal diaphragm. s; fine striation on the decorticated surface of internode.
Drawn from 2a.
2c. Lateral view of the nodal diaphragm (d). c; a tubercle caused by the thickened free-toothbase. Drawn from 2a.
Text-figs. 3a-g. Equisetites nipponicus KIMURA and TSUJI! sp. nov.
3a. A detached and broken leaf-sheath with free-teeth. Drawn from NNW --456, shown also in
PI. 39, Fig. 8.
3b. Showing crowded fin!! pits distributing on the whole surface of appressed part of leafsegments. Drawn from 3a.
3c. Showing a broken leaf-sheath on which free-teeth are still retained. Two hoop-like lines areseen on the leaf-sheath. Free-teeth are mostly reflexed at the tip and the margins. Drawnfrom NNW-796C, shown also in PI. 40, Fig. 4.
3d. A crushed leaf-sheath probably on the lower part of erect stem. Two hoop-like lines areseen on the leaf-sheath; one (a-b) below is comparatively strong and another (dotted line)
above is weak. The a-b line may indicate the position of a nodal diaphragm. Drawn from
NNW-792, shown also in PI. 39, Fig. 7.
3e. Showing leaf-segments, free-teeth and commissural furrows enlarged from 3d. Each freetooth has a midrib. The bordered line between the free-tooth and the appressed part ofleaf-segment is indistinct.
3f. A broken internode with a crushed leaf-sheath probably on the upper part of an erect stem.
Note that the fallen free-teeth leave a more or less thickened straight edge at the top of
appressed leaf-sheath. Drawn from NNW-332, shown also in PI. 39, Fig. 9.
3g. An isolated nodal diaphragm. Drawn from NNW-814, shown also in PI. 38, Fig. 10.
Text-figs. 4a-c. Equisetites sp. A.
4a. A vertically compressed cup-shaped leaf-sheath with a nodal diaphragm. Free-teeth were
all lost. Drawn from NEE-008, shown also in PI. 40, Fig. 7.
4b. Fine strong and crowded projections on the adaxial surface of leaf-sheath. Drawn from 4aenlarged.
4c. Showing the branching rhizome with cup-shaped leaf-sheaths. Drawn from NEE-002. Its
counterpart is shown in Pl. 39, Fig. 10.

352

Tatsuaki KIMURA and .Masanori TSUJII

lower part of the stem, number reduced
to about 30 on the upper nodes. Sheathon lower nodes typically 30 mm high, but
commissural furrows continued for 6",10mm (rarely 15 mm) below the node,
composed of raised leaf-segments andsunken commissural flanges; flanges
truncate above. Leaf-segment with amidrib and numerous oblong fine pits on
its outer surface of coherent part, 75",125(90) p.m long and 25",75(45) p.m wide, 65
per mm 2 in density. Free-teeth 4"'6 mmlong, elongate-triangular in shape, gradually tapering into acuminate apex, often
broken off leaving thickened horizontal
rim at upper end of coherent sheath.
Nodal diaphragm not rotated on compression, but very rarely isolated; circular,
finely granular, showing a single ring of
simple tubercles, 2"'2.5 mm from the edge,
tubercles twice as numerous as leafsegments. Rhizome sparsely branched,
7",14 mm wide with long internode.
Internode smooth but longitudinallywrinkled (thought to have been producedin compression). Nodal region more orless swollen. Leaf-sheath similar in form
to that of erect vegetative stem, and with
about 40 closely appressed leaf-segments.
(Cone and root unknown.)
Distribution and occurrence: Equisetites
nipponicus is abundant in the Negoya
Formation of the main distribution of
Kuruma Group, where it is the commonest
fossil and no other Equisetites species
has been found. Most specimens arebroken and flattened stems and rhizomes.
Accordingly it is considered that they
are not in the position of growth. In
addition, a few stem fragments referable
to this species were found at the Kotaki
Coal-Field in the northeastern subordinate
distribution of Kuruma Group.
Observations: PI. 40, Fig. 3 (holotype)shows two erect vegetative stems lying
parallel; the left one shows four faintly

preserved smooth internodes, and theright one, crowded nodes with crushed
leaf-sheaths above and appressed ones
below. The suddenly contracted base oferect vegetative stem as shown in theright might have been perpendicularly
attached to the horizontal rhizome which
was lost in the course of collection.
Nodal diaphragms are not rotated, but
represented by prominent brims in compressed stems. No evidence of branches
or bulges was recognized on the nodal
regions. These erect vegetative stems
may be from submerged bases, because
no pits (stomata) are visible anywhere.
PI. 39, Fig. 8(Text-fig. 3a) shows a single
leaf-sheath preserved obliquely to thebedding plane. Such occurrence of isolated leaf-sheaths is quite common. The
illustrated leaf-sheath is about 13 mm indiameter, more than 7 mm high and stillwith free-teeth but their apices are broken
as shown in Text-fig. 3a. Leaf-segments
are estimated at 48, 0.5"'0.6 mm wide,
connected with narrow sunken commissuralflanges, 0.12",0.24 mm in total width.
The median suture of adjoining flanges
is prominent, continuing the sunken commissural furrows below the node asclearly shown in Text-fig. 3d (PI. 39, Fig.
7). Crowded fine pits are distributed on
the whole surface of leaf-segments asshown in Text-fig. 3b enlarged. The pits
are oriented in parallel to the leaf-segment.
No pits were visible on the free-teeth.
Judging from its size, PI. 39, Fig. 9(Text-fig. 3f) may represent the upper
portion of an erect vegetative stem. Itsinternode is 9 mm wide with a compressedleaf-sheath consisting possibly of 36",38
leaf-segments. A few free-teeth are stilI
attached. Broken free-teeth are marked
by a more or less thickened edge at the
top of the leaf-sheath. The commissural
furrows below the node are indistinct inthis specimen.

718.

Early Jurassic plants

JUdging from its size, PI. 39, Fig. 7 may
represent the lower part of an erectvegetative stem. In this specimen thefree-tooth is elongate-triangular in shapewith a midrib (Text-fig. 3e, enlarged)
often with reflexed tip and margins. The
tooth-apices appear to be rounded.
The leaf-sheath show two transverse
ridges or furrows of unknown nature(Text-figs. 3c, 3d).
The more or less swollen nodal regionis shown by PI. 40, Fig. 5. All the freeteeth are lost, leaving a thickened straightedge at the top of appressed leaf-sheathas well as seen in Text-fig. 3f. The
sunken commissural furrows below thenode are clearly seen. The specimen
shown in Text-fig. 3f is unusual in
showing a transverse line across thebase of the free-teeth, such a line is,however, often seen in Equisetites
iwamu roensis.
PI. 38, Fig. 10 (Text-fig. 3g) is only an
isolated nodal diaphragm in our collection.
It is 15 mm in diameter, consisting of acentral circle with finely granular surface
and a ring of tubercles. The tubercles
are elongate-oval in shape, 2'"'-'2.5 mm long
and about 48 in number. It may correspond to the typical number of leafsegments.
Comparison:
Equisetites nipponicus
differs from E. iwamuroensis in thefollowing points: 1) Equisetites nipponicus
has 40'"'-'48 (typically 48) leaf-segments ina sheath instead of 24'"'-'28 (typically 24)
in E. iwamuroensis. 2) In E. nipponicus
free-tooth-bases left at the tip of appressedpart of leaf-segment are thickened, forming a straight rim instead of leaving a
row of thickened and trapezoid bases in
E. iwamuroensis. 3) Free-tooth of E.
nipponicus has a midrib, but such a midrib
has not been found in E. iwamuroensis.
4) The nodal diaphragms are not rotatedand rarely isolated in E. nipponicus, butthey are often rotated or isolated in E.
iwamu roensis.
Of KON'NO'S species, Equisetites koreanicus, E. nariwaensis, E. naitoi, E. naitoi
subsp. minor and E. paotensis differ inhaving branched stems, and other six
unbranched species by him have fewer
segments in their leaf-sheaths.
Equisetites jerganensis SEWARD, E.
rajmahalensis (OLDHAM & MORRIS) FEISTMANTEL and E. sarrani ZEILLER are wellknown Asiatic species. They are also
distinguishable from E. nipponicus, because
their numbers of leaf-segments are 25'"'-'32,
25'"'-'30 and 20, respectively.
Equisetites veronensis ZIGNO (ZIGNO,
1856) or Equisetites veronense (ZIGNO)(KILPPER, 1964) resembles E. nipponicus
in external form of aerial stem, but differsfrom E. nipponicus in having much laterally expanded leaf-sheath.
We know similar species to E. nipponicus
such as Equisetum columnare BRONGNIART(BRONGNIART, 1828; HARRIS, 1961) andEquisetites grosphodon HARRIS (HARRIS,
1931). Equisetum columnare is only alittle broader and has 50'"'-'80 leaf-segments(nodal bulges are only present at stembases). The Greenland Lower Liassic
Equisetites grosphodon is 15'"'-'40 mm wideand has 30'"'-'40 leaf-segments. However,so far as we know, there are no otherspecies having typically 48 leaf-segments
in a sheath.
Equisetites sp. A
PI. 39, Fig. 10; PI. 40, Figs. 7-9;
Text·Jigs. 4a-c
Material: NEE-002, 0028, 008, 057, 094,
362, NEG-059, 073 (NEE-; Higashi-Neiridani,
and NEG-; Negoyadani).

Distribution and occurrence: This form
is only known from the Negoya Formation, but rather rare.

354

Tatsuaki KIMURA and Masanori TSUJII

Descriptio1l: PI. 40, Fig. 7 (Text-fig.4a)shows an apically expanded cup-shaped
leaf-sheath with a nodal diaphragm compressed vertically. Leaf-sheath is morethan 1.2 cm high and with 74 leaf-segments.
Leaf-segments are 0.5 mm wide below
and 1.3 mm wide above, and coherent by
narrow commissural flanges above and bycommissural furrows below. Free-teeth
are unknown. On the adaxial surface ofeach leaf-segment, numerous fine projections are recognized as shown in
Text-fig. 4b. They are 90",125 (100) f1.m
long and 75 f1.m wide, and 70 per mm 2 indensity. They possibly show the positionof stomata. If so, the strong projections
are due to the greater thickness of thewall of the guard cells. Nodal diaphragm
is concave above, neither rotated nor
isolated, and about 9 mm in diameter witha narrow marginal ring consisting of
tubercles, the number of which corresponds
to that of leaf-segments.
PI. 40, Fig. 9 shows another verticallycompressed node from below. The deformed nodal diaphragm is 1.8 X 1.5 cm,

convex below and with a marginal ringconsisting of 64 tubercles. Around thenodal diaphragm, part of the leaf-sheath
extends outwards from the node.
PI. 40, Fig. 8 shows a similar specimen
to that shown in PI. 40, Fig. 9. The slightly
deformed nodal diaphragm is narrower,
1.25 xl cm in diameter, and there are 52
tubercles.
In rhizomes internodes are comparatively slender, 0.7"'1.2 cm wide with longinternodes, about 4 cm long. The surface
of internode is smooth and no pits arerecognized. Leaf-sheaths are expanded
and cup-like form, twice as wide as theinternodes. PI. 39, Fig. 10 (Text-fig. 4c)shows a nodal region and a leaf-sheathon a thicker rhizome on the right' and apossible branch on the left. The leafsheath on the right is 1.5 cm high and2.2 cm wide, and consisting of 25 (total50) leaf-segments with elongate-triangularfree-teeth, 0.3 cm long. The number ofleaf-segments is reduced on the slenderbranches.
Remarks:
Several specimens were

Explanation of Plate 38
Figs. 1-9. Equisetites iwamuroensis KI~WRA
1. A part of basal erect stem. Loc. Tsuchizawa (Kr-025). natural size.
2. A part of typical erect stem. Loc. Iwamuro (A-3051, lectotype), reappeared from KIMURA,
1959a, pI. 1, fig. 1, natural size.
3. A slender erect stem, obliquely preserved to the bedding plane. Loc. Tsuchizawa (Kr011), enlarged twice.
4. Showing acicular free-teeth. Loc. Tsuchizawa (Kr-027), enlarged twice.
5. A slender stem with long internodes. Loc. Tsuchizawa (Kr-021), enlarged twice.
6. Showing a obliquely preserved leaf-sheath to the bedding plane. Loc. Iwamuro (A-4071),
enlarged twice.
7. Ditto. Loc. Tsuchizawa (Kr-019) I enlarged twice.
8. An isolated nodal diaphragm. Loc. Iwamuro (A-3076), enlarged twice.
9. Ditto. Loc. Iwamuro (A-3093), enlarged twice.
Fig. 10. Equisetites nipponicus KIMURA and TSUJII sp. nov.; showing a single isolated nodal
diaphragm. Note that its tubercles are longer than those of Equisetites iwamuroensis. Loc.
Nishi-Neiridani (NNW -814), enlarged twice.
Fig. 11. ~quisetites sp. C; showing an isolated nodal diaphragm. Loc. Sasakomata (SAS-007),
enlarged twice.

KIMURA and TsujI!:

Eat"ly Jur-ass'ic plants

Plate 38

718.

Early Jurassic plants

obtained from the Higashi-Neiridani and
Negoyadani. The present material ischaracterized by the expanded cup-likeleaf-sheath and the numerous leafsegments on an aerial leaf-sheath, 52",,74(52 possibly common) in number. Accordingly the present material does notcorrespond to Equisetites iwamuroensis
and E. nipponicus here described.
So far as the number of leaf-segments
is concerned, the present material differsfrom hitherto known species of Equisetites
or Equisetum. So far as we know, theleaf-segments are more than 80 inEquisetites multidentatus originally described by OISHI from the Nariwa Group(OISHI, 1932, p. 266, pI. 20, figs. 1-2) and
114 in E. mori-gumpeii here described.
Under these circumstances, the present
material seems to belong to a new species,
although the aerial internodes and thecones have not been found. We, however,adhere to Equisetites sp. A to the present
material until more satisfactory data are
available.
Equisetites sp. B
Pl. 39, Fig. 11
Material: SAS-001 and 006 (counterpart)(SAS-; from Sasakomata).

Distribution and occurrence: A single
rhizome is obtained from the Shinadani Formation of Sasakomata.
Description: The rhizome is rather
slender, 1.2 cm wide, with internodes, 3""
3.5 cm long. The surface of internodes
is smooth but longitudinally and roughly
wrinkled. The leaf-sheaths are faintly
preserved in which the number of leafsegments are, 34, 40 and 40 on each leafsheath indicating by arrows in PI. 39, Fig.
11. No pits were recognized both on theleaf-segments and the internode~.
Remarks: So far as the size and the355

number of leaf-segments are concerned,
the present rhizone resembles those ofEquisetites nipponicus described here.
Owing to the ignorance of associatedaerial stems and other organs, the present
rhizome is not specifically determined,
and we call it Equisetites sp. B.
Equisetites sp. C
PI. 38, Fig. 10
Material: SAS-003, 007 (counterpart). 001
and 009 (associated leaf-sheaths) (SAS-; from
Sasakomata) .

Distribution and occurrence: A single
isolated nodal diaphragm and associatedbroken leaf-sheaths were obtained from
Sasakomata of the Shinadani Formation.
Description: The nodal diaphragm islarge-sized, but deformed, 2.2 X 3.8 cm indiameter with a marginal ring of 84
dome-shaped tubercles. The ring of
tubercles is 1.5",,1.8 mm wide.
The leaf-sheaths are 1.5 cm high above
the node and are so fragmental that wecannot make the exact number of leafsegments clear. But we suppose thatthese associated leaf-sheaths and the nodal
diaphragm belong to the same species,
because these leaf-sheaths are also largesized and the number of leaf-segments isevidently more than 62.
Remarks: The present nodal diaphragm
is obviously different in size and thenumber of tubercles from other Equisetites
species here described.
So far as the size and the number oftubercles are concerned, the present nodal
diaphragm may referable to Equisetites
multidentatus OISHI with a thick stem
and more than 80 leaf-segments on eachleaf-sheath. But in OISHI'S species, theleaf-sheaths are decidedly shorter, 0.7""1.0
cm high instead of 1.5 cm high in thepresent leaf-sheaths.

356

Tatsuaki KIMURA and Masanori TSUjII

Under these circumstances, the present
material is not specifically determined, andwe call it Equisetites sp. C.
(to be continued)

References
BOSE, M. N. & SAH, S. C. D. (1968): Somepteridophytic remains from the Rajmahal
Hills, Bihar. Polaeobotanist, vol. 16, no.
1, p. 12-28, pis. 1-7.
BROKGKIART, A. (1828-1837): Histoire desvegetaux fossiles, ou recherches botaniques
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FEIST1\!A:>1TEL, O. (1877): Jurassic (Liassic)
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Rajmahal Hills. Mem. Ceol. Surv. India,
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53-162, pis. 36-48.
HALLE, T. G. (1908): Zur Kenntnis der mesozoischen Equisetales Schwedens.
K.
svensk. Vet.-Akad. Handl., Bd. 43, p. 1-56,
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HARRIS, T. M. (1926): The Rhaetic flora of

Scoresby Sound East Greenland. Medd.
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- - (1931): The fossil flora of Scoresby
Sound East Greenland, 1. Cryptogams(exclusive of Lycopodiales). Ibid., vol.
85, nr. 2, p. 1-104, pis. 1-18.
- - (1961): The Yorkshire jurassic flora.
I. Thallophyta-Pteridophyta. ix+212 pp.
Brit. Mus. (Nat. Hist.).
KAWASAKI, S. (1939): Second addition to theolder Mesozoic plants in Korea. BUll.
Ceol. Surv. Korea (Chosen), vol. 4, no. 3,
p. 1-69, pis. 1-16.
KILPPER, K. (1964): Uber eine rat/Lias-Flora
aus dem nordlichen AbfaH des Alburs·
gebirges in Nordiran. Teil 1: Bryophyta
und Pteridophyta.
Palaeontographica,
Abt. B, Bd. 114, p. 1-78, pis. 1-15.
KI:VIURA, T. (1952): On the geological studyof the Iwamuro Formation, Tone-gun,Gumma Prefecture, Ser. 1. jour. Ceol.
Soc. japan, vol. 58, no. 685, p. 457-468(in Japanese).
- - (1959a): Mesozoic plants from the Iwamuro Formation (Liassic), Tone-gun,Gumma Prefecture, Japan (On the geologi-

Explanation of Plate 39
Figs. 1-6. Equisetites iwamuroensis KIMCRA
1. A detached internode. Loc. Iwamuro (A-2058), reappeared from KIN!URA, 1959a, pI. 1,
fig. 2, natural size.
2. Similar internodes to those shown in PI. 38, Fig. 5. Loc. Tsuchizawa (Kr-020), enlarged
twice.
3. An isolated nodal diaphragm. Loc. Iwamuro (A-75183), enlarged twice.
4. A vertically compressed nodal diaphragm (back-side view), Loc. Iwamuro (A-7577),
enlarged twice.
5. Rhizomes. Note that the surface of internode is longitudinally wrinkled. Loc. Tsuchizawa(Kr-006), enlarged twice.
6. Crushed cones and scattered sporangiophores. Loc. Tsuchizawa (Kr-009), enlarged twice.
Figs. 7-9. Equisetites nipponicus KI:VIURA and TsuJIl sp. nov.
7. A basal erect stem with short internodes. Loc. Nishi-Neiridani (NNW-792), natural size.
8. A leaf-sheath obliquely preserved to the bedding plane. Loc. Nishi·Neiridani (NNW-456),
enlarged twice.
9. A slender erect stem with a crushed leaf·sheath. Loc. Nishi-Neiridani (NNW -322), enlarged
twice.
Fig. 10. Equisetites sp. A; showing rhizomes with cup-like leaf-sheath. Loc. Higashi-Neiridani(NEE-002), enlarged twice.
Fig. 11. Equisetites sp. B; showing a rhizome; arrows show the position of nodes. Loc. Sasakomata (SAS-011), natural size.

K/lvlU RA and TSUj II :Early J~~Tassi(; plants

Plate 39

718. Early Jurassic plants
cal study of the Iwamuro Formation, Ser.
2). Bull. Sen. High Sch., Tokyo Univ.
Educ., no. 3, p. 1-59, inc I. pis. 1-12.
- - (1959b) : Mesozoic plants from the Kotaki
Coal-Field, the Kuruma Group, Central
Honshu, japan. Ibid., p. 61-83, inc I. pis.
1-2.
KOBA YASH!, K. (1948): The Kuruma Series,
at Kuruma, Kita-Azumi-gun, Nagano Prefecture. Kagaku (Science), vol. 18, no.
12, p. 563-564 (in Japanese).
KOBAYASHI, T. (1927): On the Tetori Series.
jour. Ceol. Soc. Tokyo, vol. 34, no. 401,
p. 59-65 (in japanese).
KOBAYASIIJ, T., KO:-;'ISHI, K., SATO, T., HAYA~dI, 1. & TOKliYA~'IA, A. (1957): On theLower jurassic Kuruma Group. jour.
Ceol. Soc. japan, vol. 63, no. 738, p. 182194 (in Japanese).
KO:-lISH!, K. (1954): Yamaoku Formation (AJurassic deposit recently discovered in
Okayama Prefecture). Ibid., vol. 60, no.
707, p. 325-332 (in japanese).
Ko:-;,'1'\o, E. (1962): Some species of Neocalamites and Equisetites in Japan and Korea.
Sci. Rep. Tohoku Univ., 2nd ser., spec.
vol., no. 5, p. 21-47, pis. 9-18.
LUNDBLAD, A. B. (1950):
Studies in the
Rhaeto-Liassic floras of Sweden. 1. Pteridophyta, Pteridospermae, and Cycadophytafrom the Mining District of NW-Scania.
K. svensk. Vet.-Akad. Handl. ser. 4, Bd.
1, no. 8, p_ 1-82, pis. 1-13.
OISIII, S. (1931a): On the Mesozoic plantbearing beds of Kita-Otari, Provo Shinano.
jour. Ceol. Soc. Tokyo, vol. 38, no. 449,
p. 45-50 (in Japanese).
- - (1931b): Mesozoic plants from KitaOtari, Provo Shinano, Japan. jour. Fac.
Sci., Hokkaido Imp. Univ., ser. 4, vol. 1,
no. 2, p. 223-255, pis. 16-18.
- - (1932): The Rhaetic plants from the
Nariwa District, Prov. Bitchu (Okayama
Prefecture), japan. Ibid., vol. 1, nos. 34, p. 257-380, pis. 1-35.
- - (1940): The Mesozoic floras of Japan.
Ibid., vol. 5, nos. 2-4, p. 123-480, pis. 148.
OISHI, S. & T AKAHASI-li, E. (1936): Rhaetic
plants from Provo Nagato, Japan_ A sup-357

plement. Ibid., vol. 3, no. 2, p. 114-133,
pI. 10.
OLDIIA1'v1, T. & MORRIS, J. (1863): The fossil
flora of the Rajmahal Series, Rajmahal
Hills, Bengal. Mem. Ceol. Surv. India,
Palaeont. Indica, ser. 2, vol. 1, pt. 1, p.
1-52, pis. 1-36.
SAII:\I, B. & RAO, A. R. (1933): On someJurassic plants from the Rajmahal Hills
of India. Asiatic Soc. Bengal, jour. &Proc., vol. 27, p. 183-208, pis. 11-16.
SEWARD, A. C. (1907): Jurassic plants from
Caucasia and Turkestan.
Mem. Com.
Ceol., N.S., Livr. 38, p. 1-48, pis. 1-8.
- - (1911): The Jurassic flora of Sutherland.
Phi/os. Trans. Roy. Soc. Edinb., vol. 47,
pt. 4, no. 23, p. 643-709, pis. 1-10.
- - (1912): Mesozoic plants from Afghanistan and Afghan-Turkistan. Mem. Ceol.
Surv. India, Palaeont. Indica, N. S., vol.
4, memo 4, p. 1-57, pIs. 1-7.
SIIIMAKURA, M. (1937): Studies on fossil
woods from Japan and adjacent lands.
Contrib. HI. Sci. Rep., Tohoku Imp.
Univ., 2nd. ser., vol. 18, p. 267-310, pis.
12-22; p. 1-73, pis. 1-15.
SCRAlXGE, K. R. (1966): Indian fossil pteridophytes (Botanical Monograph, no. 4). 209
pp. New Delhi.
SZE, H. C. (1931): Beitrage zur liassischen
Flora von China. Nat!. Res. Inst. Ceol.
(A cad. Sinica) , Mem. 12, p. 1-85, pis. 110.
- - (1933): Mesozoic plants from Kansu.
Ibid., Mem. 13, p. 65-76, pis. 8-10.
T AKAIIASHI, E. (1957): Fossil flora of the
Toyora and the Totonishi Groups, Yamaguchi Prefecture. Yamaguchi jour. Sci.,
vol. 8, p. 79-82 (in Japanese).
- - (1959): Floral change since the Mesozoic
age of Western Honshu, Japan. Sci. Rep.,
Yamaguchi Univ., vol. 10, p. 181-237 (inJapanese) .
TESLENKO, Yu. V. (1970): Stratigraphy andflora of the jurassic strata in Westernand Southern Siberia and Tuva (Series of
Palaeontology and Stratigraphy, no. 42).
270 pp., incl. 52 pis. Moscow (in Russian).
Y ABE, H. & OISHI, S. (1933): Mesozoic
plants from Manchuria. Sci. Rep., Tohoku

Tatstwki KIMURA and Masanori TSUjII

358

Imp. Univ., 2nd ser., vol. 12, no. 2B, p.
195-238, pis. 30-35.
YAGI, T. (1918): On the occurrence ofJurassic plants from Kita-Otari, Provo
Shinano.
jour. Geol. Soc. Tokyo, vol.
25, no. 293, p. 79-81 (in Japanese).
YOKOYAMA, M. (1904): On some Jurassic
fossils from Rikuzen. jour. Coll. Sci.,
Imp. Univ. Tokyo, vol. 18, art. 6, p. 1-13,

pis. 1, 2.
ZEILLER, R. (1903): Etudes des gUes mineraux de la France, flore fossile des gUes deCharbon du Tonkin. 320 pp., 56 pis. Paris.
ZIG:-IO, A. de (1856): Flora fossilis Formationis Oolithicae. Le Piante Fossili
dell'Oolite. vol. 1, Livr. 1. 32 pp., 6 pis.
Padova.

Dairagawa :;t:ijZ)II,
Higashinagano }.I:[;l~:!f,Higashi-Neiridani
Daedong (Korea) *1l'1J,
JIVf~A~,
Iwamuro ~~,Jogodani im4~,
Katashinagawa Jt&MII,
Kitamatadani~tx~,
Kita-Otari ~t'H~,
Komyoshita J't;§IrF,
Kotaki 'HI[,
Kurobishiyama ~~rLr,
Kuruma *,~,
Mizukamidani *J:~,
Nariwa 1ll1:;pJ,
Negoya fj;ltJU~,
Neimong(China) P'J~,
Neiridani r;tA~,
Nishi-Neiridani i1lj~A~,
Omi 'ftifij,
Sang un ~m,
Sasakomata iE'J'X,
Shimodera -F~i'"
Shinadani ~\i',~,Shizugawa *'r\tJII,
Teradani~~,
Tsuchizawa ±tR,
Yamaoku !11!11!!:

B*(7)1JjJtl];;,,-:7*c.IDl¥!.J1tEo -t-cr)1 : B*(7)1Jj:M;;,,-:7*c.11ti¥!.J1tElt, ~rl1i!Hl:f}.ld~!fM (lJIIJY~),
rLr!11!!:m (!lliIrLr~), *}!!f;II~ ('iii 1.1I , tfi~, *!f~), ~~~~ (~,~~), *'itJllm~ (??;~~) n'I?~1?
h"(\"oo tJJ:(7)?~, ;ft1i¥!.J1tE~~.i!E-t0(7)It, *,~m~:tt;.tO'~~~m-c-.:I;oo ;fAC'tlt, ;:(7)~1f.rI39
I;::bt.: ~, *,~II~:tt;.t O'~~mmn' 1?~:lll:(7)j[{¥!.J1tE~l*U~ Lt.:(7)-C, ;: hI? 'Z' B*(7)fJJ;ltJJ;; "" :7 *c.;ft1i¥!.J~(7)~ • • ~L"(U • • ~E • • • ~-too*ffifBJtlt, .i!E:It!!(7):It!!'i!t:tt;.to:Vt:*.*~nt.:~fltl;::'?\,'"( i!l{t&-to~ ~ tl;::, ~ <~ § 1;::.Jm.-t 0,
Equisetites iwamuroensis KIMURA, E. mori-gumpeii KIMURA and TS(;JII sp. nov., E. nipponicus
KIMURA and TSUJI[ sp. nov., E. sp. A, E. sp. B :tt;.t0' E. sp. C ~E.Lt.:oB*(7)1Jj;ltJJ;; "- :7 *c.;flj'{~~(7)!f.T-ll:tt;.t O'fl!!.ttk.l!i1G(7)ll'1Jlfift\:;l7)l1tt¥!.J~ ~ (7)Lt~lt:l&~i.I~I;::.:tt;\',"(;m"" o=f~"('.:1;0*tt~~ . H::JtIEJW
0Explanation of Plate 40
Figs. 1-2. Equisetites iwamuroensis KI~IURA
1. A slender erect stem with a rotated nodal diaphragm. Loc. Tsuchizawa (Kr-013), enlarged
twice.
2. A small-sized cone supported by an erect stem. Loc. Iwamuro (A-7901B) , enlarged twice.
Figs. 3-6. Equisetities nipponicus KIMURA and TSUJII sp. nov.
.
3. Basal part of two erect stems. Loc. Nishi-Neiridani (NNW -800, holotype), natural size.
4. A broken leaf-sheath. Loc. Nishi-Neiridani (NNW-796C), enlarged twice.
5. Showing a leaf-sheath, of which all the free-teeth are lost. Loc. Nishi-Neiridani (NNW796B), enlarged twice.
6. A leaf-sheath with free-teeth. Loc. Higashi-Neiridani (NNW -811), enlarged twice.
Figs. 7-9. Equisetites sp. A.
7. A vertically compressed leaf-sheath with nodal diaphragm (upside view). Loc. HigashiNeiridani (NEE-008), enlarged twice.
8. Ditto. (back-side view). Loc. Negoyadani (NEG-059), enlarged twice.
9. Ditto. Loc. Higashi-Neiridani (NEE-094), enlarged twice.

K I MURA

and TSUjff:

Early Jtwassic 1Jlants

Plate 40

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 119, pp. 359-370, pIs. 41, 42, September 30, 1980

719.

VISEAN BRACHIOPODS FROM THE KARA UMEDATEFORMATION, SOUTHERN KITAKAMI MOUNTAINS*
JUN-ICHI T AZA WA
Institute of Geology and Paleontology,
Tohoku University, Sendai 980

Abstract. A late Visean brachiopod fauna consisting of 9 species is describedfrom the uppermost part of the Karaumedate Formation at Jizodo, Nagasaka area,
Southern Kitakami Mountains, Northeast Japan. It contains a new species: Kara.
vankina jizodoensis.
The late Visean age assignment for the Jizodo fauna does not contradict thestratigraphic data suggesting that the Karaumedate Formation is conformably over·lain by the Upper Visean to probable Westphalian Takesawa Formation.

ISHIZAKI (1968) described some ostracodesfrom the formation, and noted that "theTakezawa Formation may be, in the caseof the youngest age, equivalent to the
Visean to which the Onimaru Formation
has been correlated, or more likely to
the Osagian in age" (lSHIZAKI, 1968, p.
12). Judging from the fossil evidences
mentioned above, the TakesawaFormation,
at least the lower part of it, is regarded
as late Visean in age.
In the previous works, it has been considered that the Karaumedate Formation
is equivalent to the Lower Tournaisian
Hikoroichi Formation, while the Takesawa
Formation is correlated with the Upper
Visean Onimaru Formation plus the
Namurian to Westphalian Nagaiwa Formation, and there is a considerable
stratigraphic break between these twoformations (IwAMATSU, 1975; MINATO,1952, 1955; MINATO and KATO, 1978;
MINA TO et al., 1979; ONUKI, 1956, 1969;
T ACHlBANA, 1952a, 1952b). However, theage of the upper part of the Karaumedate
Formation has not been substantiated,

Introduction
Brachiopod fossils treated in this paper
were collected from the uppermost partof the Karaumedate Formation exposedat the hill of Jizodo, Higashiyama-Cho,
Higashiiwai-Gun, Iwata Prefecture, i. e. theNagasaka area, western marginal part of
the Southern Kitakami Mountains, Northeast Japan (Text-fig. 1). The fossils areabundant in grey, tuffaceous sandy slateof about 20 m in thickness. The sandy
slate occupies the top of the Karaumedate
Formation which consists mainly of sandstone and attains a thickness of about
260 m at Jizodo. This fossiliferous sandy
slate is conformably overlain by darkgrey limestone of the lower part of theTakesawa Formation.
The latter contains the following
smaller foraminifer and corals: Endothyra?
sp., Palaeosmilia sp., Dibunophyllum sp.
and Lonsdaleia sp. (OSA w A, 1980 MS).

* Received March 12, 1980; read June 9,
1979, at Tatsunokuchi.
359

Jun-ichi l'AZA W A

360

tof the Institute of Geology and Paleontology,
Tohoku University, who kindly gave him
the information on the geology of theNagasaka area. He also thanks Professor
Kei MORI of the same institute for his
critical reading of the manuscript. Photographs are the work of Mr. Shohei OTOMO
of our institute.

-III

Mt.TobigamoriA

Age of the Fauna

323

The brachiopod fauna of Jizodo consisting of 9 species described in thispaper is listed below.
---:::7L-.,.L-""::::""""'-..I...--t-'::"::"':+--- 39· 0 0'

o _--'-_----I,2 km
L..'

Text-fig. l.
locality.

Map showing the fossil

because all of the early Tournaisianbrachiopods and trilobites described fromthe Nagasaka area (MINATO, 1952;
T ACHIBANA, 1956, 1969; KOBAYASHI andT ACHIBANA, 1978) are regarded as specimens from the lower part of the Karaumedate Formation or the upper part ofthe "Upper Devonian" Tobigamori Formation.
Recently T AZA WA and OSA WA (1979)
reported the occurrence of Martinia,
an element of the Jizodo fauna, andpointed out that the top of the Karaumedate
Formation is a late Visean in age and it
is conformably overlain by the Takesawa
Formation.
The purpose of this paper is describe
the brachiopods of the Jizodo fauna andto discuss its stratigraphic significance.
The present author thanks Messrs. Masahiro OSAWA and Hiroshi N AGURA, students

Rugosochonetes sp.
Krotovia sp.
Productus ct. P. concinnus J. SOWEIWY
Karavankina jizodoensis, sp. nov.
Balakhonia sp.
Yanishewskiella ? sp.
Brachythyris ct. B. elliptica ROllERT";
Phricodothyris sp.
Martinia aff. M. glabra 0. SOWER£lY)

Among these species, K. jizodoensis andM. aff. M. glabra are dominant.
The genera Productus s. s., Balakhonia
and MaI,tinia are not found below the
Visean (MUIR-WOOD and COOPER, 1960,
p. 240; MUIR-WOOD and WILLIAMS, 1965,
p. H903 ; CARTER, 1975, p.73). In addition,
Phricodothyris is not common below the
Visean (CAMPBELL, 1957, p. 37). On theother hand, the genus Brachythyris is notfound above the Visean (BOUCOT et aI., 1965,
p. H707). The species closely related to
the Jizodo forms, such as Phricodothyris
tripustulosa DEMANET and Martinia glabra(J. SOWERBY) are characteristic Upper
Visean elements. Brachythyris elliptica
ROBERTS is considered to be ranging up
into the Upper Visean (ROBERTS, 1975,
table 1).
The Jizodo fauna from the uppermost
part of the Karaumedate Formation isregarded as late Visean in age. This

719.

Visean hrachiopods from Northeast Japanconclusion does not contradict the factthat the fossiliferous sandy slate of the
topmost part of the Karaumedate Formation is succeeded upwards by thelimestone of the Takesawa Formation
without any structural discordance.
The genus Karavankina has hitherto
been described from the Upper Carboniferous and the Lower Permian (RAKUSZ,
1932; RAMOVS, 1966, 1969; SARYTCHEVA,
1968; WINKLER PRINS, 1968; YANAGIDA
and A w, 1979), but not known from theLower Carboniferous. So the new species,
K. jizodoensis is the oldest record of thegenus in the world.

361

But the specific assignment is uncertain.
In Japanese Carboniferous, only one
species of Rugosochol1etes has hitherto
been described: Rugosochonetes aff. R.
hardrensis (PHILLIPS) from the Lower
Namurian of Akiyoshi, Southwest Japan(Y ANAGIDA, 1965, p. 115, pI. 27, figs. 2-8;
YANAGIDA et aI., 1977, p. 141). The
Akiyoshi specimens differ from the present
form in their smaller dimensions.

Suborder Productidina W AAGEN, 1883
Superfamily Productacea GRAY, 1840
Family Overtoniidae MUIR-WOOD

Description of Species

and COOPER, 1960

Order Strophomenida OPIK, 1934

Subfamily Overtoniinae MUIR-WOOD
and COOPER, 1960

Suborder Chonetidina MUIR-WOOD, 1955
Genus Krotovia FREDERICKS, 1928
Superfamily Chonetacea BRONN, 1862
K rotovia sp.

Family Chonetidae BRONN, 1862
PI. 41, Figs. 2a, 2b.

Subfamily Rugosochonetinae
MUIR-WOOD, 1962
Genus Rugosochonetes SOKOLSKAJA, 1950
Rugosochonetes sp.
PI. 41, Figs. la, lb.

Material :-One specimen; internal moldof a pedicle valve: IGPS colI. cat. no.
96252.
Remarks :-This specimen is assigned
to the genus Rugosochonetes on the basisof its high median septum in the pedicle
valve which is originating slightly anterior
to the beak and extending to about onethird of the length of the valve. The
Kitakami specimen is characterized by
its a pair of vascular trunks, which arecommencing at just anterior to the endof, and parallel to, the median septum.

Material :-One specimen; external castof a pedicle valve: IGPS colI. cat. no.
96253.
Remarfls:- This single specimen is
assigned to the genus K rotovia on thebasis of its size, shape and ornamentation.
The specimen from Jizodo is a small,transverse subrectangular, and slightly
convex pedicle valve, ornamented byirregular, concentric rows of spine bases
and numerous weak growth lines.
Externally, this specimen somewhat
resembles the shells referred to Krotovia
granulosa (PHILLIPS), figured by WINKLER
PRINS (1968, p. 80, pI. 1, figs. 25-30) fromthe Upper Carboniferous of the Cantabrian
Mountains, Northwest Spain. But the
Kitakami specimen is an incompletematerial and not sufficient for the accuratecomparison to the Spanish specimens.

Jun-ichi TAZAWA

362

Family Productidae GRAY, 1840
Genus Productus J. SOWERBY, 1814
Productus d. P. c:mcinnus

J. SOWERBY, 1821
Pl. 41, Figs. 3-6.

Compare with
1928 Productus concinnus: MUR-WOOD, p. 49,
pI. 1, figs. 7-10; text-fig. 12.
1952 Productus concinnus: SARYTCIIEV A andSOKOLSKA]A, p. 134, pI. 37, fig. 184.

Material :-Four specimens; (1) externalmold and cast of a pedicle valve: IGPS
colI. cat. no. 96254, (2) external casts of
two pedicle valves: IGPS colI. cat. no.
96255, 96256, (3) external mold of abrachial valve: IGPS colI. cat. no. 96257.
Description :-Shell small size for the
genus, transverse subrectangular in outline, with long trail. Hinge line straight,
a little less than the greatest width of
the shell; the latter occurring near theanterior margin of the shell. Length
13 mm, width 17 mm (lGPS colI. cat. no.
96256); length of trail over 13 mm (lGPS
colI. cat. no. 96254).
Pedicle valve with slightly convex
visceral disc, geniculated into trail withalmost right angles. Umbo small, rounded
and incurved. Ears rather large, clearlymarked off from visceral disc. Shallow
sulcus on visceral disc. Lateral slopes
steep. Median fold may be present on
trail.
Brachial valve with almost flattened
visceral disc, strongly geniculated. Diaphragm horizontally extends around theanterior and lateral margins of the visceraldisc of brachial valve, widest at the
middle portion and its measurements 6 mm,
tapering posterolaterally.
External surface of pedicle valve
ornamented by regularly developed costellae; 8 costellae in 5 mID. width near theanterior margin of the visceral disc, 7
costellae in 5 mm width on trail. Rugae
on visceral disc. Very fine growth lines
on the whole surface of the valve; theyespecially visible on trail. No spine bases
observed. Brachial valve ornamented byfine costellae and some weak rugae on
visceral disc; 14 to 18 costellae in 5 mm
width near the anterior margin. Diaphragm rather smooth except for somesparse costellae.
Remarks :-The present specimens aresafely assigned to the genus Productus
s. s. on the basis of its long trail and a
crescent-shaped, flattened diaphragm.
The Kitakami specimens resemble theshells of Productus concinnus J. SOWERBY
from the Upper Visean (D 2) to lower
Upper Carboniferous (Millstone Grit) of
Britain (MUIR-WOOD, 1928), and the Upper
Visean to Namurian of the Moscow Basin(SARYTCHEVA and SOKOLSKAJA, 1952) insize, and having relatively large ears anda median fold on trail of pedicle valve.
Productus productus (MARTIN) is distinguished from the present form by its
larger dimensions, smaller ears, andcoarser, more irregular costellae.
Productus sp. described from the Lower
Carboniferous Arisu Formation of theKitakami Mountains (MINA TO, 1951, p.
366, pI. 1, figs. 4a, 4b) may be assigned
to the subfamily Dictyoclostinae STEHLI,
1954.
Family Echinoconchidae STEHLI, 1954
Subfamily Karavankininae.... RAMovS, 1966
Genus Karavankina RAMovs, 1966
Karavankina jizodoensis, sp. nov.
PI. 41, Figs. 8-16; PI. 42, Fig_ 14;
Text-fig. 2.

719.

Visean brachiopods from Northeast Japan

Material :-Eighteen specimens; (1)external and internal molds of a conjoined
valve: IGPS colI. cat. no. 96258 (holotype),(2) external and internal molds of two
pedicle valves: IGPS colI. cat. no. 96259,
96260, (3) internal molds of two pedicle
valves: IGPS colI. cat. no. 96261, 96262,(4) external mold of a brachial valve andinternal mold of a conjoined valve: IGPS
colI. cat. no. 96263, (5) internal mold of aconjoined valve: IGPS colI. cat. no. 96264,(6) external and internal molds of twobrachial valves: IGPS colI. cat. no. 96265,
96266, (7) external molds of four brachialvalves: IGPS colI. cat. no. 96267, 96268,
96269, 96270, (8) internal molds of threebrachial valves: IGPS colI. cat. no. 96271,
96272, 96273, (9) external molds of fragments of valves: IGPS colI. cat. no. 96274,
96275.
Diagnosis :-Large-sized, transverse subrectangular-shaped species of Karavankina.
Ornamentation of wider lamellose bands
with one row of large spine bases andtwo rows of small ones. Interior ofbrachial valve with a ventrally bilobed,
but dorsally unknown, cardinal process.
Description :-Shell large size for the
genus, transverse subrectangular in outline.
Hinge line straight, a little less than thegreatest width of the shell; the latteroccurring at slightly anterior to mid valve.
Length 21 mm, width 40 mm in the holotype.
Pedicle valve gently convex in bothprofiles; without sulcus.
Ears large,
flattened, trigonal in shape, and clearly
demarcated from visceral disc by a concavity.
Umbo rounded and strongly
incurved. Brachial valve almost flattened
at visceral disc, weakly concave near theanterior and lateral margins of the valve;
no fold.
Both valves ornamented by concentriclamellose bands bearing numerous, elongate
spine bases. Bands narrower and more

3()3regular on brachial valve; 4 to 5 bands
in 10 mm length on pedicle valve, 8 to 9
bands in 10 mm length on brachial valve.
Two series of spine bases concentricallyand more or less quincuncially arrangedon each band (PI. 2, Fig. 14). Larger spine
bases forming a single row posteriorly,
and two rows of smaller ones occurring
anteriorly; 3 larger spine bases and 24
to 30 smaller spine bases in 5 mm width
at the anterior portion of brachial valve.
Internally, pedicle valve having narrow,elongated, smooth adductor scars at theposterior portion of the valve. Brachialvalve having elongate trigonal-shaped
buttress plates on both sides of median
septum; the latter thin, extending to about
one-third of the length of the valve. A
ventrally bilobed, but dorsally unknown,
cardinal process supported by two buttress

Text·fig. 2. Posterior portion of thebrachial valve interior of J(aravankina
jizodoensis, sp. nov. (ICPS colI. cat. no.
96264), showing cardinal process, lateralridges, buttress plates and median septum.

Jun-ichi TAZAWA

364

plates and lateral ridges (Text-fig. 2).
Lateral ridges short, slightly diverging
from hinge line. Adductor scars andbrachial ridges not observed.
Remarks :-In outline of shell, andhaving rather large ears, the Kitakami
species resembles Karavankina dobsinensis(RAKUSZ) from the Moscovian of Hungary(RAKUSZ, 1932, pI. 2, figs. 21, 22; pI. 3,
fig. 2), and Karavankina ct. K. dobsinensis
from the Moscovian of Spain (WINKLER
PRINS, 1968, p. 96, pI. 4, figs. 17, 19) andthe Moscovian of Malaysia (YANAGIDA
and Aw, 1979, p. 128, pI. 29, figs. 6a, 6b).
But they differ from the present form intheir smaller shells ornamented bynarrower bands.
Karal'an/lina rakuszi WINKLER PRINS
from the Moscovian of Spain (WINKLER
PRINS, 1968, p. 97, pI. 4, figs. 11-16, 18,
20; text-fig. 16) is also having a ventrallybilobed cardinal process. But the Spanish
species differs from the present form in
its highly convex pedicle valve withnarrower lamellose bands.
Karaz'allllina typica RAMOVS and
Karavan/lina paraelegans (SARYTCHEVA)
are clearly distinguished from the Kitakami
species by their small-sized, subtrigonalshaped pedicle valves.

Family Linoproductidae STEHLI, 1954
Subfamily Linoproductinae STEHLI, 1954
Genus Balakhonia SARYTCHEVA, 1963
Balakhonia sp.
PI. 41, Fig. 7.

Material :-One specimen; external moldof a brachial valve: IGPS coIl. cat. no.
96276.
Remarks:-This specimen is assigned
to the genus Bala/?honia on the basis of
its ornamentation. The surface ornamentof this valve consists of costellae andsome irregular rugae.
The costellae
themselves are sculptured with numerous,
very fine growth lines. This feature isthe characteristic of Balakhonia.
The specific determination is impossible
for this poorly preserved specimen.
Order Rhynchonellida KUHN, 1949
Superfamily Rhynchonellacea
GRAY, 1848
Family Tetracameridae
LIKHAREV, 1956
Genus Yanishewskiella LIKHAREV, 1957
Yanishewskiella? sp.
PI. 42, Figs. 1a-4.

Matel'ial :-Four specimens; (1) externalmold and cast of a pedicle valve: IGPS
coil. cat. no. 96277, (2) external mold of apedicle valve: IGPS coIl. cat. no. 96278,(3) external molds of two brachial valves:
IGPS coIl. cat. no. 96279, 96280.
Remarks:- These specimens may be
assigned to the genus Yanishewskiella bytheir small, rhynchoneIIiform shells witha few subrounded costae, although theirinternal structures are unknown.
The Kitakami specimens superficiallyresembles the shells of Janischewskiella (?)
angulata (JANISCHEWSKY), figured by
KALASHNIKOV (1974, p. 100, pI. 38, fig. 8)
from the Namurian of the Northern Urals.
Yanishewskiella japonica YANAGIDA
from the Lower Namurian of Akiyoshi(Y ANAGIDA, 1962, p. 117, pI. 19, figs. 45; pI. 20, figs. 1-2; text-figs. 18, 19;
YANAGIDA et aI., 1977, p. 141) differsfrom the present form in its short costae
occurring only near the anterior marginof the valve.

719.

Visean brachiopods from Northeast Japan

Order Spiriferida W AAGEN, 1883
Suborder Spiriferidina W AAGEN, 1883
Superfamily Spiriferacea KING, 1846
Family Brachythyrididae
FREDEI{ICKS, 1919 (1924)
Genus Brachythyris M'CoY, 1844
B rachythy ris ct. 13. elliptiC([

ROBERTS, 1963
Pl. 42, Figs. 12a-13.
Compare with
1963 Brachythyris elliptica

ROIlERTS,

p. 17,

pl. 4, figs. 1-4.

Material:- Three specimens; (1) external and internal molds of a pedicle valve:
IGPS colI. cat. no. 96281, (2) internal moldof a conjoined valve: IGPS colI. cat. no.
96282, (3) internal mold of a pedicle valve:
IGPS colI. cat. no. 96283.
Description :-Shell large size for the
genus, transverse elliptical in outline.
Hinge line straight and short. Cardinal
extremities rounded. Pedicle valve moderately convex with the maximum convexity
at umbo. Beak small, pointed and strongly
incurved. Brachial valve flattened except
for the slightly convex umbo and broad,low fold. Length 22 mm, width 79 mm in
the largest specimen (lGPS colI. cat. no.
96281).
Fold commencing at umbo, becoming
broader anteriorly, and subdivided by amedian groove and three minor furrows.
Plicae rounded, bifurcated near the anterior
margin; 14 to 16 plicae on pedicle valve,
14 plicae on brachial valve.
Pedicle valve interior, with some
vascular markings radially branching out
from the umbonal portion.
Remarks :-In size, shape and ornamentation, the present species is most similar365

to 13rachythyris elliptica ROBERTS, described by ROBERTS (1963) from the Upper
Tournaisian Bingleburra Formation of
Lewinsbrook, New South Wales.
13rachythyris htakamiensis MINATO
from the Lower Carboniferous Hikoroichi
Formation of the Kitakami Mountains(MINATO, 1951, p. 368, pI. 3, fig. 3; pI. 4,
fig. 1) somewhat resembles the present
form in having a fold of the GEORGE'S(1927, p. 108) group A of Brachythyris
species (Brachythyris pinguis Group) on
the brachial valve. But the comparison
to this species is difficult, because B.
kitakamiensis has been established based
only on a single specimen of brachialvalve (UHR 16465).
Suborder Delthyrididina IVANOVA, 1972
Superfamily Reticulariacea
W AAGEN, 1883
Family Elythidae FREDERICKS,
1919 (1924)
Genus Phricodolhyris GEORGE, 1932
Phricodothyris sp.
Pl. 42, Figs. 5a, 5b.

Material :-Onespecimen; external moldof a brachial valve: IGPS colI. cat. no.
96284.
Remarlls:- The specimen from Jizodo
is represented by a brachial valve of a
medium-sized,
wider
Phricodothyris
species, probably a new form. This
species is characterized by its ornamentation which consists of numerous, concentrically and regularly arranged spine
bases and interspinous pustules; namely,
three interspinous pustules are always
recognized between two spine bases (PI.
2, fig. 5b). The spine bases show thecharacteristic of double-barreled spines,Jun-ichi l'AZA W A

366

and are counted 18 to 20 in 10 mm width
near the anterior margin of the valve.
The present species is most similar to
Phricodothyris tripustulosa DEMANET,
described from the Upper Visean (V 3) ofBelgium (DEMANET, 1938, p. 95, pI. 9, figs.
11-15, text-fig. 29). But the Belgian
species is smaller in size, and its valve isornamented by more closely arranged
spine bases (30 to 40 in 10 mm width;
after DEMANET, 1938 p. 96).
Phricodothyris sp. from the Lower
Permian Sakamotozawa Formation of theKitakami Mountains (NAKAMURA, 1959, p.
200, pI. 1, figs. 1a-1c) is clearly distinguished from the present form by its
ornamentation which is similar to that of
Neophricadothyris asiatica (CHAO).
Superfamily Martiniacea
W AAGEN, 1883
Family Martiniidae W AAGEN, 1883
Subfamily Martiniinae W AAGE1\, 1883
Genus Martinia

M'CoY, 1844

Martinia aft. M. glabra

o. SOWER BY, 1820)
PI. 42, Figs. 6-Ub.
1927 Martinia aff. M. glabra: GEORGE, p. 112,
text·figs. 3-11.
1938 Martinia aff. M. glabra: DOIA0iET, p.
103, pI. 9, figs. 24-29.
1979 Martinia sp.: TAZAWA and OSA\VA, p.
775, text·Jigs. 2.1a-2.5b.

Nlaterial:-Thirty-three specimens; (1)external molds of three pedicle valves
and internal molds of three conjoined
valves: rGPS colI. cat. no. 96285, 96286,
96287, (2) external molds of three brachialvalves and internal molds of three conjoined valves: rGPS colI. cat. no. 96288,
96289, 96290, (3) external and internalmolds of a pedicle valve: rGPS colI. cat.
no. 96291, (4) internal molds of four conjoined valves: rGPS colI. cat. no. 96292,
96293, 96294, 96295, (5) internal molds oftwenty-two pedicle valves: rGPS colI. cat.
no. 96296, 96297, 96298, 96299, 96300, 96301,
96302, 96303, 96304, 96305, 96306, 96307,
96308, 96309, 96310, 96311, 96312, 96313.
96314, 96315, 96316, 96317.
Description :-Shell medium size for the
genus, transverse suboval in outline.
Hinge line straight, much less than thegreatest width of the shell; the latteroccurring at or slightlY anterior tomidvalve.
Umbo narrow and highly
inflated. Beak pointed and incurved.
Cardinal extremities well rounded. Length
23 mm, width 51 mm in the largest
specimen (IGPS colI. cat. no. 96291).
Pedicle valve gently convex except for theumbonal portion and median sulcus. Sulcus
shallow and broad, originating at slightly
posterior to midvalve.
Brachial valve
slightly convex, almost flattened near theposterior and lateral margins of the valve.
Fold low and broad, developing at
anterior half of the valve. Externalsurface of both valves smooth.
Pedicle valve interior, muscle scars
small, rhomboidal, and impressed at slightly below the umbo; some vascularmarkings radially branching out fromaround muscle scars and extending to twothirds of the length of the valve. Brachialvalve interior with elongate muscle scars
at posterior portion of the valve; vascularmarkings not observed.
Remarks :-MUIR-WOOD (1951, p. 111)
proposed that the trivial name Conchyliolithus Anomites (glaber) of MARTIN, 1809
should be referred to J. SOWER BY, 1820("The Mineral Conchology of GreatBritain" vol. 3, p. 123). She selected thelectotype of Martinia glabra O. SOWERBY)(BM(NH) BB.l02; MUIR-WOOD, 1951, pI. 3,
figs. 2a-2c) from the SOWERBY'S material.

719.

Visean brachiopods from N01°theast JapanThe specimens from Jizodo resemble
the lectotype in shape and having broadand shallow sulcus. But the comparison
to M. glabra is difficult, because theinternal structure of the lectotype isunknown.
The Kitakami specimens are quite
similar to the sheils, figured as Martiniaaff. M. glabra (MARTIN) by GEORGE (1927)
and DEMANET (1938), from the Upper
Visean of Wales and Dinant, respectively.
Martinia aff. M. glabra (J. SOWERBY)
from the Namurian of Spain (MARTINEZCHACON and WINKLER PRINS, 1977, p. 22,
pI. 11, figs. 2a-2c) differs from the present
form in its weakly developed sulcus.
The shells referred to Martinia glabra
var. decora PHILLIPS, from the Lower
Carboniferous of Omi, Central Japan(HA YASAKA, 1924, p. 48, pI. 6, fig. 14) isdistinguished from the present form by
its very narrow sulcus on the pedicle
valve.

References
Bm:COT, A.J., JOHNSON, J.G., PITRAT, C.W.
and STATON, R. D. (1965): Spiriferida.
Invert.
in MOORE, R. C. (ed.) Treat.
Paleont., Part H (Brachiopoda 2), p. H632H728, Geol. Soc. Amer. and Univ. Kansas
Press.
CAMPBELL, K. S. W. (1957): A Lower Carboniferous brachiopod-coral fauna from
New South Wales. Jour. Paleont., vol.
31, no. 1, p. 34-98, pis. 11-17.
CARTER, J. L. (1975): Lower Carboniferous
brachiopods from Axel Heiberg and MelvilleIslands, Canadian Arctic Archipelago.
Bull. Amer. Paleont., vol. 67, no. 287, p.
71-97, pis. 1-4.
DEMANET, F. (1938): La faune des couches
de passage du Dinantien au Namurien dansIe synclinorium de Dinant. Mem. Mus. r.
Hist. Nat. Belg., no. 84, p. 1-201, pis. 114.
GEORGE, T. N. (1927): Studies in Avonian
Brachiopoda: 1. The genera Brachythyris

367

and Martinia. Geol. Mag., vol. 64, p.
106-119.
HA YASAKA, I. (1924): On the fauna of the
Anthracolithic Limestone of Omi-Mura in
the western part of Echigo. Sci. Rep.,
Tohoku Imp. Univ., 2nd ser., vol. 8, no.
1, p. 3-83, pis. 1-7.
!SllIZAKl, K. (1968): On some Carboniferous
ostracodes from the Takezawa Formation,
Northeast Japan. Saito Ho-on Kai Mus.
Res. Bull., no. 37, p. 11-17, pl. 2.
I\\"AMATSL', A. (1975): Folding-styles andtheir tectonic levels in the Kitakami and
Abukuma Mountainous Lands, Northeast
Japan. Jour. Fac. Sci., Univ. Tokyo, ser.
2, vol. 19, no. 2, p. 95-131, pis. 4-7.
KALASll:>:IKOV, N. V. (1974) : KAJIAWHI1KOB,
H. B. : PaHHeKaMeHHoyroJIbHble 6paXJcIOnO.llbl OeQOpCKOro YpaJIa. 166 p., 52 pis.,
HaYKa, JIeHHHrpa.ll.
KOBAYASllI, T. and TACIIIBA:'\A, K. (1978):
A new Carboniferous trilobite from Nagasaka, Iwate Prefecture and its bearings
on taxonomy and biogeography. Proc.
Japan Acad., ser. B, vol. 54, no. 6, p.
262-267.
MARTINEZ CHACO:>:, M. L. and WINKLER PRINS,
C. F. (1977): A Namurian brachiopod
fauna from Mere (Province of Oviedo,
Spain). Scripta Geologica, vol. 39, p. 138, pis. 1-14.
MINATO, M. (1951): On the Lower Carboniferous fossils of the Kitakami Massi"f,Northeast Honsyu, Japan. Jour. Fac.
Sci., Hokkaido Univ., ser. 4, vol. 7, no. 4,
p. 355-382, pis. 1-5.
- - (1952): A further note on the Lower
Carboniferous fossils of the Kitakami
Ibid.,
Mountainland, Northeast Japan.
vol. 8, no. 2, p. 146-174, pis. 2-11.
- - (1955): Zur stratigraphischen Lucke der
Pra-Onimaru-Serie (Ober Vise) in Japan.
Ibid., vol. 9, no. 1, p. 31-41.
- - , HUNAI-IASHl, M., WATANABE, J. and
KATO, M. (ed.) (1979): Variscan Geohistory of Northern Japan: The Abean
Orogeny. 427 p., Tokai Univ. Press, Tokyo.
- - and KATO, M. (1978): The Carboniferous
in the Kitakami Mountains. Geol. Surv.
Japan, Rep., no. 258, p. 3-13.

368

Jun-ichi T AZA W A

MUIR-WOOD, H. M. (1928): The British Carboniferous Producti 2. Productus (sensu
stricto) semireticulatus and longispinus
group. Geol. Surv. U. K. (Palaeont.)
Mem., vol. 3, pt. 1, p. 1-217, pis. 1-12.
- - (1951): The Brachiopoda. of Martin's"Petrificata Derbiensia". Ann. Mag. Nat.
Hist., ser. 12, vol. 4, p. 97-118, pis. 3-6.
- - and COOPER, G. A. (1960): Morphology,
classification and life habits of the Productoidea (Brachiopoda).
Geol. Surv.
Amer., Mem., 81, p. 1-447, pis. 1-135.
- - and WILLIAMS, A. (1965) : Strophomenida;
Addendum. in MOORE, R. C. (ed.) Treat.
Invert. Paleont., Part H (Brachiopoda 1,2),
p. H361-H521, H903, Geol. Soc. Amer. andUniv. Kansas Press.
NAKAMURA, K. (1959): Some Lower Permian
Sakamotozawa brachiopods. jour. Fac.
Sci., Hokkaido Univ., ser. 4, vol. 10, no.
1, p. 199-207, pis. 1, 2.
O:-':UKI, Y. (1956): Geology of the Kitakami
Massif. Explanatory text of geologic map(scale 1: 100,000) of Iwate Prefecture.
189 p., Iwate Prefecture. (in Japanese)- - (1969): Geology of the Kitakami Massif,

Northeast Japan. Contr., Inst. Geol. Pal.,
Tohoku Univ., no. 69, p. 1-239, pis. 1-4.
(in Japanese)
OSAWA, M. (1980 MS): Geology of the Takesawa area, Higashiyama-Cho, HigashiiwaiGun, Iwate Prefecture. (Graduation thesisof the Institute of Geology and Paleontology, Faculty of Science, Tohoku University;
in Japanese)
RAKUSZ, G. (1932): Die oberkarbonischen
Fossilien von Dobsina (Dobsina) und
Nagyvisnyo. Geologica Hungarica (Palaeont.), T. 8, p. 1-223, pis. 1-9.
RA~IOVS, A. (1966): Revision des "Productus
elegans" (Brachiopoda) in ostalpinen
JungpaUiozoikum. N. jb. Geol. Paliiont.
Abh., Bd. 125, p. 118-124, pI. II.
- - (1969): Karavankininae, nova poddruzina
prod uk tid (Brachiopoda) iz Alpskih zgornjekarbonskih in Permijskih skladov.
jeseniski Zbornik jeklo in Ljudje, II Del,
p. 251-268, pis. 1-3.
ROJ3ERTS, J. (1963): A Lower Carboniferous
fauna from Lewinsbrook, New South
Wales. jour. Proc. Roy. Soc. N. S. W.,
vol. 97, pt. 1, p. 1-31, pis. 1-6.

Explanation of Plate 41(Nat. size unless otherwise specified)Figs. la, lb. Rugosochonetes sp.
Internal mold of pedicle valve: IGPS coil. cat. no. 96252 (lb. x 2).
Figs. 2a, 2b. Krotovia sp.
External cast of pedicle valve: IGPS coil. cat. no. 96253 (2b. x 3).
Figs. 3-6. Productus cf. P. concinnus J. SmYERBY
3. External cast of pedicle valve: IGPS coil. cat. no. 96256, 4. Rubber cast of pedicle valve
exterior: IGPS coil. cat. no. 96254, 5. External cast of pedicle valve: IGPS coil. cat. no.
96255, 6. External mold of brachial valve: IGPS coil. cat. no. 96257.
Fig. 7. Balakhonia sp.
External mold of brachial valve: IGPS coil. cat. no. 96276.
Figs. 8-16. Karavankina jizodoensis, sp. nov.
8. Rubber cast of brachial valve interior: IGPS coil. cat. no. 96272, 9a. External mold of
pedicle valve, 9b. Internal mold of pedicle valve, 9c. External mold of brachial valve, 9d.
Internal mold of brachial valve: IGPS coil. cat. no. 96258 (holotype). 10. Internal mold of
pedicle valve: IGPS coil. cat. no. 96261, lla. Internal mold of pedicle valve, 11b, llc.
Internal mold of brachial valve: IGPS coil. cat. no. 96264 (11c. x 3), 12a. External mold ofbrachial valve, 12b. Rubber cast of brachial valve interior: IGPS coil. cat. no. 96259, 13.
External mold of brachial valve: IGPS coil. cat. no. 96269, 14. External mold of fragment ofvalve: IGPS coil. cat. no. 96275, 15. External mold of brachial valve: IGPS coil. cat. no.
96267, 16. Internal mold of brachial valve: IGPS coil. cat. no. 96265 (x 3).

TAZAWA:

Visean brachiopods

Plate 41

9a

12a

14

12b

719.

Visean brachiopods from Northeast Japan- - (1975): Early Carboniferous brachiopod
zones of Eastern Australia. jour. Ceol.
Soc. Aust., vol. 22, pt. 1, p. 1-31.
SARYTCHEYA, T. G. (1968):
CAPbI4EBA,
T. f.: 6paXHOnO.1lbl BepxHero naJle030H
BOCTO'lHOrO Ka3axcTaHa. Tp. nI1H., T.
121, p. 1-212, pis. 1-33.
- - and SOKOLSKAJA, A. N. (1952): CAPbI·
4EBA, T. f. Ii COKOJIbCKMI, A. H. :Onpe.1leJlHTeJl'b naJleo3oj:jcKHX 6paXHOnO.1l
nO.1lMOCKOBH0l1 KOTJlOBHHbl. Ibid., T. 38,
p. 1-303, pis. 1-71.
T ACHll3ANA, K. (1952a): On the Tobigamori
Group of the Nagasaka district, Kitakami
Mountainland, Part 1. jour. Ceol. Soc.
japan, vol. 58, no. 683, p. 353-360. (injapanese)(1952b): Ditto, Part. 2. Ibid., vol. 58,
no. 684, p. 445-455. (in japanese)- - (1956): New spiriferids from the Lower
Carboniferous of the Nagasaka district,
Kitakami Mountainland, Northeast japan.

Sci. Rep., Fac. Arts and Lit., Nagasaki
Univ., no. 5, p. 11-16, pl. 1.
- - (1969): Stereoscopic photographs anddescriptions of new syringothyroid bra·
chiopods from the Lowest Carboniferousof the southwestern Kitakami region,
Northeast japan. Ann. Rep., Fac. Edu.,
Univ. /wate, vol. 28, pt. 3, p. 19-27, pis.
1-6.

Akiyoshi 'f:X.W,
Arisu :{,J-fj:,
Hikoroichi E~m,
Iwate :!fi~,
Nagaiwa *:!fi,Nagasaka *)&,
Takesawa ¥rtR.

369

TAZAWA, J. and OSAWA, M. (1979): Occur·
rence of Martinia sp. (Brachiopoda) fromthe Lower Carboniferous Karaumedate
Formation, Southern Kitakami Mountains
and its significance. jour. Ceol. Soc.
japan, vol. 85, no. 12, p. 775-777. (injapanese)
WI:"'IKLER PRINS, C. F. (1968): Carboniferous
Productidina and Chonetidina of theCantabrian
Mountains(NW
Spain):
Systematics, stratigraphy and Palaeoecol·ogy. Leidse Ceol. Med., vol. 43, p. 41126, pis. 1-9.
YAl'AGIDA, J. (1962): Carboniferous brachiopods from Akiyoshi, Southwest japan,
Part 1. Mem. Fac. Sci., Kyushu Univ.,
ser. D, vol. 12, no. 1, p. 87-127, pis. 1421.
- - and Aw, P. C.(1979): Upper Carboniferous,
Upper Permian and Triassic brachiopods
from Kelantan, Malaysia. in KOllAYASIlI,T., TORIYAMA, R. and HASIll:VIOTO, W.
(ed.)
Ceology and Palaeontology ofSoutheast Asia, vol. 20, p. 119-141, pis.
27-29, Univ. Tokyo Press.
- - , OTA, M. and NAGAI, K. (1977): On
the faunas of the Millerella zone in the
Akiyoshi Limestone Group. Sci. Rep.,
Dept. Ceol., Kyushu Univ., vol. 12, no.
3, p. 139-146, pI. 13. (in japanese)

Higashiiwai-Gun *l!;JUII,
Higashiyama-Cho JU,lJIIIJ,
Jizodo :l1!!~1ii-:,
Karaumedate r,g:f/lJfu'!,
Kitakami ~t.1:,
Omi Wifij,
Onimaru ;1&::k.,Sakamotozawa ~*tR.,--------- ---------~$~t.1:i1l:l1!!O)r,g:f/lJml~.t I) ilirl±l L.t.: ~ _l:! -WlJl)\j)~m : ~$~t.1:ill:l1!!*~:l1!!~, :l1!!~1ii-:t::.ittil_t omff/lJtlli~O)Jtt.1:$~.t I), 9:fl0)~.@m;b>I~:,t.co1~Wl~-l:!-J\Jl0)7 *--r;bt~l?;h,t.:O)--CllCJliJ(;_to. :'0)~}tm7* --r1t.1 ~:fla--E;tf : Kararankina jizodoensis.
:l1!!il"£7 * --r;bq~M ~ -tt-Wla-~_t:. ~ It., ~Hl.itl1'!I~;b~.1:tLO)H:il ~ -l:!-!IM'-'/ '" A r 7 7 Y 7!1M'(?)t'r
tR.~t::'~~EfJt::.m:b;h,o ~ \"? !f71-*~~ ~~ lA.c\,'.
1TItR.*,Iji-370

Jun-ichi 1'AZAWA

Explanation of Plate 42(Nat. size unless otherwise specified)Figs. la-4. Yanishewskiella? sp.
la, lb. Rubber cast of brachial valve exterior: IGPS call. cat. no. 96280 (lb. x 2), 2. Rubber
cast of brachial valve exterior: IGPS call. cat. no. 96279 (x 2), 3. Rubber cast of pedicle
valve exterior: IGPS call. cat. no. 96278 (x 2), 4. Rubber cast of pedicle valve exterior:
IGPS call. cat. no. 96277 (x 2).
Figs. 5a, 5b. Phricodothyris sp.
5a. External mold of brachial valve, 5b. Enlarged portion of Fig. 5a showing doublebarreledspine bases and interspinous pustules: IGPS call. cat. no. 96284 (5b. x 20).
Figs. 6-lIb. Martinia aff. M. glabra (J. SmmRlw)
6. Internal mold of pedicle valve: IGPS call. cat. no. 96313, 7. Internal mold of pedicle
valve: IGPS call. cat. no. 96315, 8. Internal mold of pedicle valve: IGPS call. cat. no. 96296,
9a. Internal mold of pedicle valve, 9b. Internal mold of brachial valve: IGPS call. cat. no.
96294, 10. Internal mold of pedicle valve: IGPS call. cat. no. 96307, lla. Rubber cast of
pedicle valve exterior, lIb. Internal mold of pedicle valve: IGPS call. cat. no. 96291.
Figs. 12a-13. Brachythyris d. B. elliptica ROBERTS
12a. Internal mold of pedicle valve, 12b. Internal mold of brachial valve: IGPS call. cat. no.
96282, 13. Internal mold of pedicle valve: IGPS call. cat. no. 96281.
Fig. 14. Karavankina jizodoensis, sp. nov.
Enlarged portion of Fig. 15 of PI. 41, showing elongate spine bases (x 5).

TAZAWA,'

Visean brachiopods

Plate 42Sa

Trans. Proc. Palaeont. Soc. Japan, N.S., No. 119, pp. 371-387, pis. 43-45, September 30, 1980

720.

ONTOGENIES OF A FEW UPPER CAMBRIAN TRILOBITESFROM THE DEADWOOD FORMATION,
SOUTH DAKOTA*
CHUNG-HUNG HU

Department of Physics, Taiwan Normal University, Taipei

Abstract. The present report illustrates the ontogenic deveolpment of three
species of trilobites and two species of agnostids. They are: Aphelotoxon triangulata,n. sp., Pulchricapitus davisi KURTZ, Housia ovata PALi\·IER, Pseudagnostus communis(HALL and WIIITFIELD), and Homagnostus tumidosus (HALL and WHlTFIELD). The
former three species are well known and the latter ones are incomplete. The studiedmaterials were all collected from the Deadwood Formation, Upper Cambrian, Elvinia
Zone, South Dakota. The result of this study indicates that the phylogenic development of Aphelotoxon triangulata is related to Ponumia, Housia, and Clijjia, and thatof Pulchricapitus davisi to Coosina and Wilsonella. The meraspid Housia ovata ispossibly diversified from some species of cooselloid-Coosia longocula P AD·IER or
Coosella convexa T ASCII.

Housia canadensis WALCOTT (Hu, 1970),
Cliffia typica Hu (1979), and H. ovata

Introduction

PALMER of the present study, and may
suggest that these genera are derived
from a similar or common ancestor.
The late meraspid cranidium of Aphelotoxon triangulata has a narrow preglabellar
field similar to those of adult forms
reported from the Dunderbergia Zone by
PALMER (1965), shows the recapitulationof its earlier progenitors.
The meraspid cranidium of Pulchricapitus davisi is morphologically similar
to the adult forms of Coosina (LOCHMAN,
1959), and Wilsonella (Hu, 1968); it
suggests that the ancestor of this genus
is possibly a cooselloid form. The latemeraspid cranidium of Housia ovata shows
the characteristics of Coosia and Coosella(LaCHMAN, 1959).
It possibly derived
from some species of cooselloid such as
Coosia longocula PALMER (1962) or

The purpose of the present report is toillustrate the ontogenic development of
three species of trilobites and two speciesof agnostids. They are: Aphelotoxon triangulata, n. sp., Pulchricapitus davisi
KURTZ, Housia ovata PALMER, Pseudagnostus communis (HALL and WHITFIELD), and Homagnostus tumidosus (HALL
and WHITFIELD). The growth series ofthe first three species are well known
and those of the other ones are incomplete.
The occurrence of the species Aphelotoxon triangulata possibly pertains to thelatest member of the Elvinia Zone, however, its early progenitor occupies mainly
the Dunderbergia Zone. The earliest
instars of this species are closely similar
to those of Ponumia obscura (LOCHMAN),* Received March 12, 1980.
371

372

Chung-Hung Hu

Coosella convexa TASCH (Hu, 1968).
The ontogenic development of Pseudagnostus communis and Homagnostus
tumidosus are incompletely known. However, it may generally be stated that thedistinct morphologic variations during
their ontogenic stages are rather simple;
i. e., the axial lobe changes from narrow
to wide and the pygidial margin becomesnarrower. Since the ontogenic development of agnostids is poorly known, their
phylogenie details are not predictable.
The studied materials were all collectedfrom the Deadwood Formation, Upper
Cambrian, Elvinia Zone, along the Black
Hills, South Dakota, during attendance ofa summer field camp, 1962. These
collections were made under the supervision of Dr. Christina LacHMAN-BALK,New Mexico Institute of Mining and
The author wishes toTechnology.
express his thanks for her guidance
during the field work. Appreciation also
goes to Dr. K. E. CASTER, University ofCincinnati, for reading over the present
manuscript. All of the figured specimens
are stored in the Geology Museum,
University of Cincinnati (GMUC), Ohio,
U.S.A.

Systematic Paleontology

Family Agnostidae WHITEHOUSE, 1936
Genus Pseudagnostus KAEKEL, 1909
Pseudagnostus communis (HALL &WHITFIELD)

PI. 43, Figs. 1-8 and Text-fig.

Agnostus communis HALL and WHITFIELD,
1877, p. 228, pI. 1, figs. 26, 27.
Agnostus neon HALL and WHITFIELD, 1877, p.
229, pI. 1, figs. 25, 26.
Pseudagnostusjosepha (HALL) : FREDERICKSON,
1949, p. 362, pI. 72, fig. 17.

Pseudagnostus prolongus (HALL and WHITFIELD): PAL!lIER, 1955, pI. 19, fig_ 18;
LaCHMAN & He, 1959, p. 412, pI. 57, figs.
7-16_
Pseudagnostus communis (HALL and WHITFIELD): PAL:"IER, 1955, p. 94, pI. 19, figs.
16, 19-21, pI. 20, figs. 4-11, 14; KURTZ,
1975, p. 1021, pI. 4, figs. 3, 4. (synonymy
up to date)

Remarks.-About a dozen small andlarge sized instars and mature specimens
have been recovered from a light graylimestone. They are identical with thoseoccurrences from the Dunderburg Shalereported by PALMER (1955). The earliest
instars of the present study are assigned
to the late meraspid stage which equals
the "adult stage" of PALMER (1955, p. 95,
pI. 20, figs. 6, 9, 10). In this stage theglabella is slenderly conical and the preglabellar field is narrow, and the pygidial
terminal portion is narrow and sharply
posteriorly pointed.
It is interesting to note that in theearlier instar the pygidial terminal portionis narrow conical, and deeply delimitedby dorsal furrows. This conical axis
increases in width during ontogeny, andthe dorsal furrows are divergent laterally;
the posterior terminal furrow is faint toevanescent. During this development
there is simultaneously developed a pairof faint grooves, or new axis, along themedian lobe. These morphologic characteristics might indicate that the original
axial furrows, those marked along thepygidial terminal portion, may hark backto an ancestral agnostid form, and the
median grooves are a newly developed
axis of a secondary nature. The author
believes that the paired furrows, present
posterolaterally from the sides of thesecond axial ring, are original dorsal
furrows which degenerated secondarily.
The two rows of pits or grooves which
are present along the median terminal

720.

Ontogenies of Cambrian T1-ilobites

portion are a secondary feature, and are
possibly muscle scars which are impressed
upon the exoskeleton (Text-fig. IF;
PALMER, 1955, pI. 20, figs. 11,14). If thispostulation is reasonable, then evite likely
the early instars of this animal was apelagic or swimming form; it may have
employed the pygidium functionally as auropod much as is show in some crustaceans without appendages, while in theadult Pseudagnostus communis the animal
become benthonic with well-developed appendages. Hence the stronger muscle
scars. KOBAYASHI (1935) indicated, andPALMER (1955) agreed, that the diagonal
furrows are accessory and the median
lobe, i. e., new axial lobe is a pseudolobe.
However, they give no phylogenic discussion of these morphologic characteristics.
Occurrence.-North side of road cut,
Little Elk Creek, about 10 miles northwest of Rapid city, South Dakota,
Figuredspecimens.-GMUC,
43413,
43414a-g.
Genus Homagnostus HOWELL, 1935

373

Homagnostus tumitosus (HALL
and WHITFIELD)
PI. 43, Figs. 9-12 and Text·fig. 2
Agnostus tumidosus (HALL and WHITFIELD),PALMER, 1960, p. 63, pI. 4, figs. 1, 2;
KeRTz, 1975, p. 1021, pI. 4, figs. 1, 2.
(synonymy to date.)

Remarks.-A few specimens wererecovered from a light gray limestone.
They are associated with Pseudagnostus
communis (HALL and WHITFIELD). The
smallest cranidium is about 0.6 mm insagittal length, showing a quadrate outline;
the preglabellar field is slightly concave.
The pygidium is 1.8 mm in length (sag.),in an adult form with a rather broad axial
lobe and a round terminal portion.
A few small pygidial shields have beenreported from the Eureka district of
Nevada by PALMER (1955). These show
the axial lobe to be conical, tapering
posteriorly and divided into three subequal segments. It is clear that in its
morphogenic sequence of this species theaxial lobe (especially on pygidial axis)

A

B

c

o

E

F

Text·fig. 1.
Pseudagnostus communis (HALL and WIIITFIELD) .. A, B: .twomeraspid cranidia, x 28, x 16; C, holaspid cr~nidiu~,. x 13; D, merasPld. pygldlUm,
x 20; E, F, a small and a large sized holaspld pygldla, x 15, x 8. (drawmgs weremade from photographs.)

Chung-Hung Hu

374

A

B

c
Text-fig. 2.
Homagnostus tumidosus
and WHITFIELD).
A, meraspid
cranidium, x 29 ; B, a small holaspid
cranidium, x 10; C, an holaspid pygidium,x 11. (all drawings were made from photographs.)(HALL

increases in breadth, and the preglabellar
field becomes convex. These are thecommon morphogenic characters of theagnostid group.
Occurrence.-North-side of road cut,
Little Elk Creek, about 10 miles northwestof Rapid city, South Dakota.
Figuredspecimens.-GMUC.
43414,
43414a-d.
Family Unassigned
Genus Pulchricapitus KURTZ, 1975
Pulchricapitus davisi KURTZ
PI. 43, Figs. 14-32 and Text-fig. 3

Pulchricapitus davisi
pl. 2, figs. 24-26.

KURTZ,

1975, p. 1038,

Remarks. - The present species is represented by both mature and immature

specimens. The morphologic characteristics are identical with those of silicified
materials reported from Missouri by
KURTZ (1975). The present materials andalso the Missouri ones all show two
different morphological groups; i. e., onewith short truncato-conical glabella andbroad fixigenae, the other with narrowelongate glabella, and narrow and relatively convex fixigenae. This bimodal phenomenon may indicate sexual dimorphism
within the same species population. The
first group is postulated as female andthe later as male as is commonly shownby many trilobites, i. e., Welleraspis late(Ru, 1964), Coosella convexa TASCH (Ru,
1968), Welleraspid swartzi TASCH (Ru,
1968), Pelthopeltis arbuklensis STITT (Ru,
1975) etc.
Occurrence.-Galena section, about 4
miles southeast of Deadwood city, South
Dakota.
Figuredspecimens.-GMUC.
43416,
43416a-r.

Pulchricapitus davisi KURTZ,
ontogeny
Metaprotaspid stage (PI. 43, Fig. 14 andText-fig. 3D).-The shield is subround inoutline, moderately convex, and is about
0.3 mm in length; the axis and the pleuron
are marked by a shallow but recognizabledorsal furrow; the axis contains a large
frontal lobe, three pairs of central nodes
and a small terminal tubercle; the threepairs of central nodes are faintly delimited
by longitudinal and transverse furrows;
the anterior pits are faintly depressed;
the pleural lobe is about the same width
as the axis. The instar's surface isminutely granulated.
Paraprotaspid stage (PI. 43, Figs. 15-17
and Text-fig. 3B, C).-The shield consists
either protopygidium or a cranidial shield

720.

Ontogenies of Camb1"ian Trilobites

375

D

c

B

E
F

G

H

I

K

Text-ftg. 3. Pulchricapitus dadsi KlKI'Z. A, an immature iibrigena, x 10; 8, C, two paraprotaspid shields, x 21, x 35; D, a metaprotaspid shield, x 47; E, an early meraspid cranidium,x 24; F, a late meraspid cranidium, x 23; G, a small holaspid cranidium, x 13; H, an immaturepygidium, x 15; I, J, two holaspid cranidia, showing the morphologic varieties, x 8, x 14. (alldrawings were made from photographs.)

only; the cranidium is about 0.4 to 0.55
mm in length (sag.) and moderately convex;
the axis is divided into five rings bytransverse ring furrows; the frontal lobe
which is distinctly demarked by a pair ofeyebrow ridges, it extended from thesides of the frontal lobe and runs
posterolaterally to end in front of thepalpebral lobes; the palpebral lobe isnarrow, elevated ridge, situated in frontof the transverse mid-line of the glabella;

the occipital ring is lenticular, convex,
and deeply separated by the occipital
furrow; the pleuron of the fixigena iseither about the same width as the axis,
or slightly wider, and convex. The
skeletal surface is faintly granulated.
During the present stage the protopygidium appears, the cylindrical glabella
becomes wider, and the transverse ring
furrows are shallower, the median longitudinal furrows disappear, and the palpebral

376

Chung-Hung Huridges are located poster to the eye-browridges.
Early memspid stage (PI. 43, Figs. 1820, 22 and Text-fig. 3E).-The cranidium
is trapezoidal in outline, moderately
convex, and is about 0.6-0.75 mm insagittal length; the dorsal furrow is
deeply demarked; the glabella is cylindrical, expands both anteriorly and posteriorly
from the anterior second glabellar furrow;the glabellar furrows are deeply demarked
laterally and shallowly so across thecentral axis; the lenticular occipital ringis convex both vertically and posteriorly,
and possibly bearing a minute mediannode; the narrow anterior border arches
forward and is well elevated; it ismarked by a frontal furrow; the fixigena
is triangular, convex, and of about thesame width as the glabella between thepalpebral lobe and the dorsal furrow; theposterior fixigena is broad, and the wellelevated fixigenal border is narrower thanthe occipital ring (tr.); the anterior suture
is convergently convex, and the posterior
one is posterolaterally divergent and isstraight without any curvature. The
skeletal surface is covered by faintgranules.
In the morphogenesis of the present
stage the glabella increases in width, theglabellar furrow becomes complete, theanterior border appears and develops
from narrow to wide, and the palpebral
lobe moves backward from the side of
the anterior border.
Late meraspid stage (PI. 43, Figs. 23-25,
31 and Text-fig. 3F).-The late meraspid
cranidium is trapezoidal in outline, moderately convex, and is about 0.75-1.24 mm
in length (sag.); the dorsal furrow is
deeply impressed; the glabella is conical,
tapering slightly forward, convex, andhas three pairs of short glabellar f.urrows ;the occipital ring is crescentically convex,
bearing a minute median node, and iswell separated by a deep occipital furrow;the narrow preglabeUar field slopes downward from the anterior glabellar marginand distinctly delimited frontal furrow;the anterior border is narrow, arches
forward, and is convex; the convex
fixigena is less narrow than the glabella
and with narrow palpebral lobe located at
the transverse mid-line of the glabella;
the posterior fixigena is triangularly
convex; the fixigenal border is elevated,deeply delimited by a border furrow, andis about the same width as that of theoccipital ring; the anterior facial sutureline is divergently convex, and the posterior one is posterolaterally divergent.
The crescentic meraspid librigena isgently convex, with the ocular platform
and the lateral border of about the same
width; the lateral border is narrow, faint,
and continuous with a medium-sized genal
spine. The skeletal surface is coveredby both faint and coarse granules.
In the morphogenesis during the present
stage the preglabellar field increases inwidth; the glabella becomes a shorter
cone; the fixigena is narrower than in theprevious stage and the palpebral lobe
moves backward, becoming situated on the
mid-length of the glabella.
Remarlls.-The protaspides of the present species are closely similar to thoseof Aphelaspis, Pambolinoides (Hu, 1969),
Glyphraspis (Hu, 1971), Welleraspis (Hu,
1964, 1968). This possibly indicates thatthey originated from a common ancestral
stock; the mer asp ides are similar to theadult forms of Wilsonella (Hu, 1968) andCoosina (LOCHMAN, 1959), which suggeststhat these two genera may be the nearest
progenitors of Pulchricapitus.
Family Solenopleuridae
ANGELIN, 1854

720.

Ontogenies of Cambrian Trilobites

Subfamily Acrocephalitinae

HUPE, 1953
Genus Aphelotoxon PALMER, 1965
The family assignment of the present
genus has been discussed by PALMER(1965), who suggested that it has somesimilarities to the genera Dresbachia,
Menomania, and Densonella, etc. This
may not tenable, due to the fact that allof these genera have a rather forwardly
located palpebral lobe, broader posterior
fixigena, proparian facial suture, andnarrower glabella. P ALMER at the sametime suggested also Aphelotoxon is similar
to Clelandia-an early Ordovician trilobite
without family assignment.
Hu (1970)
believed Aphelotoxon, Cliffia, Ponumia,
and Elyaspis (KURTZ, 1975) to be naturalgroup, since they have several characteristics in common: all possess a triangularcranidium, broad conical glabella, small
palpebral lobe located rather forwardly
to the anterior border, nearly triangularpygidium, and coarse granulated skeletons.
The author proposes that all of these fivegenera; i. e., Aphelotoxon, Cliffia, Pontl1nia,
Elyaspis, and Clelandia are solenopleurids,
belonging to the Subfamily Acrocephalitinae HUPE (1953).
Aphelotoxon triangulata, n. sp.
PI. 44, Figs. 1-31 and Text-fig. 4

Diagnosis.-Cranidium trapezoidal tosubtriangular in outline, and convex;
glabella broad conical, rounded anteriorly,marked by three pairs of glabellar
furrows; occipital ring transverse triangular, convex, bearing a minute mediantubercle; no preglabellar field is known;
the anterior border is deeply delimited bya broad frontal furrow; fixigena slopes
downward below the glabella, being
narrow triangular, and about one-third377

the width of the glabella between thesmall palpebral lobe and the dorsal furrow;the posterior fixigenal border is morethan one-half the width of the occipitalring, convex, and elevated from the broadborder furrow. Librigena nearly crescentic,
convex, and possesses a small short genal
spine. Pygidium triangular to rhombic,
convex; axial lobe narrow conical, sharply
pointed posteriorly divided into 6 axial
rings by furrows; the pleural lobe is lessnarrow than the pleural lobe, convex,
with deeply impressed interpleural grooves;no distinct inner marginal furrow is known.
Description.- The cranidium is trapezoidal to triangular in outline, convex, witha disitnct dorsal furrow; the glabella isbroadly conical, tapering forward with arounded anterior margin and faintly
defined by three pairs of distinct glabellar
furrows; the anterior first pair of glabellar
furrows is the shortest and faint; thesecond and third pairs are longer anddeeply impressed; all of them are directed
obliquely posterolaterally from the dorsal
furrows; the occipital ring is crescentic,
convex both vertically and posteriorly,
and bears a medium-sized spine, and aminute median tubercle; the occipital
furrow is narrow and shallow across thecentral axis, and deeply impressed laterally; no preglabellar field is known; thenarrow lenticular anterior border isconvex both vertically and horizontally,and deeply delimited by a frontal furrow.
The fixigena is about one-third thewidth of the glabella between the smallelevated palpebral lobe and the dorsal
furrow; the palpebral lobe is situated in
front of the mid-line of the glabella (tr.),and continuous with a narrow palpebral
ridge directed obliquely toward the anterolateral glabellar margin; the posterior
fixigena is triangular, convex, slopes
downward from the dorsal furrow, andwith a convex posterior fixigenal border;

Ch'ttng-Hung Hu

378

A

c

o

E

B

H

J

K
Text-fig. 4. Aphelotoxon triangulata n. sp. A, anaprotaspid shield, x 52; B, metaprotaspid
shield, x 50; C-E, paraprotaspides, x 42, x 42, x 40; F, G, early meraspid cranidia, x 45, x 35;
H, late meraspid cranidium, x 20; I, L, holaspid cranidia, x 21, x 24; K, hypostoma, x 2; J, M,
an immature and a mature pygidia, x 21, x 10. (drawings were made from photographs.)

the posterior fixigenal border is morethan one-half as wide as the occipitalring between the dorsal furrow and thelateral end; the anterior facial suture isconvergently convex; and the posteriorfacial suture is divergent posteriorly fromthe posterior margin of the palpebral lobe,
and with a round fixigenal angle.
The librigena is crescentic, convex,
with a short slender genal spine projected
posteriorly; the ocular platform is medium-wide, slightly convex, with a faint lateralfurrow; the small ocular ridge is locatedin front of the mid-line (tr.) of the freemargin-the facial suture line.
The pygidium is rhomboid in outline,
convex, and has the dorsal furrow welldepressed; the axis is conical, tapering
posteriorly to end in a sharply pointed
projection, and it is not extended the fulllength of the pygidium; the five to six
convex axial rings are well marked, of720.

Ontogenies of Camb1'ian Trilobites

which the anterior two are complete, andthe posterior ones are incompletely
divided; the pleural lobe is about twothirds the width of the axis, convex, andslopes downward from the inner third;
no distinct inner marginal furrow orspines are visible. The surface of theexoskeleton is covered by medium-sized
granules.
Remarlls.- The present species is represented by more than a hundred matureand immature skeletons which shown awell preserved growth sequence. It isdifferentiated from the published speciesof PALMER (1965): Aphelotoxon acuninata
PALMER, A. punctata PALMER, A. gramllosus PALMER, A. limata PALMER, A.
spinosus PALMER, and A. marginata
PALMER, from the Dunderbergia Zone by
the absence of the preglabellar field,
shallower dorsal furrow, and the broadly
rhomboid pygidium. It is interesting tonote that the immature or the latemeraspid cranidium has a narrower preglabellar field similar to the adult forms
found from the Dunderbergia Zone, but
this feature absence latterly. It shows
the recapitulatory phenomenon.
Occurrence.-South side of Dark Canyon,
about 4 miles west of Rapid city, South
Dakota.
Figured specimens.-Holotype, GMUC.
43417y; paratypes, GMUC. 43417, 43417ax, Z, a'-c'.

Aphelotoxon triallgulata, n. sp.,

ontogeny
Anaprotaspid stage (PI. 44, Figs. 1, 2
and Text-fig. 4A).-The shield is subroundin outline, moderately convex, and about
0.25-0.28 mm in length (sag.); the dorsal
furrow is faintly impressed; there are no
axial segments and the terminal lobes arerecognizable; the posterior shield margin37~)

is bent inward, and with the posterolateralcorners projected posteriorly.
The
fixigena is slightly narrower than theaxial lobe or of about the same width as
the axis; no marginal border furrow is
known; the paired frontal pits are rather
faint and located near the anterior shield
margin; the surface of the instars is
minutely granulated.
Metaprotaspid stage (PI. 44, Figs. 3-5
and Text-fig. 4B).-The shield is subroundin outline, convex, about 0.30-0.35 mm insagittal length, and with a rather faintly
demarked dorsal furrow; the axial lobe
has no defined segmental ring or furrows,
except for faint longitudinal dorsal
furrows; the anterior pits are faintly
impressed; the skeletal surface is coveredby minute granules.
The distinct characteristics of this stage
are that the axial lobe is well defined bydorsal furrows, the posterior shield margin
with a well development marginal borderand a median terminal lobe-the occipitalring.
Paraprotaspid stage (PI. 44, Figs. 6-11
and Text-fig. 4C, D).-The shield is subround in outline, convex, about 0.40-0.48
mm in sagittal length, and with thepleural and axial lobes well defined bydorsal furrows; the axial lobe is slenderly
fusiform, convex, and tapering slightly
both anteriorly and posteriorly; no defined
axial ring or segmental furrows are seen.
except for three or four pairs of pits
along the dorsal furrows; the terminal
portion of the axial lobe is occupied bya small lenticular occipital ring; thepaired frontal pits are minutely depressed,and delimited by a pair of supercilioid
ridges; the posterior fixigenal border isnarrow near the occipital ring but broadenslaterally, convex, well demarked by aborder furrow; behind the cephalic shield
is a transverse lenticular protopygidium,
which slopes downward rapidly, and is380

Chung-Hung Hu

divided into two or three axial rings bysegmental furrows; the axial rings areconvex, with well defined axis andfurrows. The surface of the shield iscovered by faint granules.
The morphogenic characteristics of thepresent stage are that the posterior
cephalic shield has a well developed
fixigenal border, the protopygidium ispresent, the anterior pits become shallower,
and the rudimentary glabellae furrows arevisible.
Early meraspid stage (PI. 44, Figs. 1119 and Text-fig. 4F, G).-The early meraspid cranidium is trapezoidal in outline,
convex, about 0.60-0.75 mm in length(sag.), and has the dorsal furrow distinctly
impressed; the glabella is conical, tapering
forward, and faintly demarked by three
to four pairs of glabellar furrows; theoccipital ring is transversely triangular,
convex, bearing a median spine, anddistinctly separated by an occipital furrow
which deepens laterally and shallowly
across the central line; no preglabellar
field is known; the narrow anteriorborder arches forward and is faintly
marked by a frontal furrow; the fixigena
is about the same width as the glabella
or slightly narrower, convex, slopes
roundly downward from the dorsal
furrow; the narrow elongate palpebral
lobe is situated in front of the transverse
mid-line of the glabella, and has the faintelevated palpebral ridge directed from thepalpebral lobe to the anterolateral marginof the glabella; the posterior fixigenal
border is convex, elevated, distinctly
marked off from the fixigenal borderfurrow, and is about the same width as
the occipital ring; the anterior facial
suture line is convergently convex, andthe posterior one is laterally divergent;
the skeletal surface is minutely granulated.
During the present stage, the anteriorborder appears and it expands fromnarrow to wider, the glabella changes
from the same width as the glabella tonarrower; the glabellar furrows are faintand complete.
Lale meraspid stage (PI. 44, Figs. 2124 and Text-fig. 4H).-The late meraspid
cranidium is trapezoidal in outline, moderately convex, and is 0.85 to 1.2 mm inlength (sag.); the glabella is broad conical,
distinctly delimited by dorsal furrows,
and has three pairs of well recognizablefurrows; the convex occipital ring is
crescentic, bearing a medium-sized occipitalspine, and possibly a minute mediantubercle; the occipital furrow is transverse
W-shaped, slightly deepens laterally andshallows across the central line; thenarrow preglabellar field is slightly
depressed at the central portion, and thedistinct frontal furrow arches less inwardly; the anterior border is gently
convex, narrowly crescentic, arches anteriorly; the convex fixigena slopes downward from the dorsal furrow, and is about
one-third the width of the glabella; thesmall palpebral lobe is deeply demarked
by a palpebral furrow; it is elevated,convex, and located in front of the midline of the glabella (tr.); the posterior
fixigenal border is about two-thirds as
wide as the occipital ring (tr.), distinctly
marked off by a broad border furrow, andis elevated and convex; the anterior facial
suture is gently convergently convex, andthe posterior facial suture line is divergently convex. The cranidial surface isfaintly granulated.
The supposedly meraspid pygidium (PI.
44, Figs. 28, 29 and Text-fig. 4J), is transversely semicircular in outline, convex,
and separated into 3-5 free segments;
the broad axis is convex, elevated fromthe pleural lobe, and tapers posteriorly;
the pleural bends are directed posterolaterally, and distinctly demarked by interpleural grooves; no pleural border or

720.

Ontogenies of Cambrian Trilobites

furrows are known. The surface of theskeleton is covered by medium-sized
granules along the anterior and theposterior half of the pleural bends.
Family Housiidae HUPF:, 1953
Genus Housia WALCOTT, 1916
Four species are known of this genus:
Housia varra WALCOTT, H. canadensis
WALCOTT, H. caccuna (WALCOTT) (W ALCOTT, 1924, 1925), and H. ovata PALMER(1965). Most of these are preserved in ashale matrix or sandstone. Therefore,
the original features of the animal aresomewhat obscure, especially the natureof the convexity due to compaction of
the bed rocks. The present materials are
identical with H. ovata reported fromGreat Basin region by PALMER (1965)
and from Missouri by KURTZ (1975); allare embedded in a limestone without
deformation. PALMER (1965) distinguishedthis species on the presence of the genal
spine and relatively elongate pygidium.
It is the author's opinion that these
specific criteria may not be tenable,
because the genal spine may be absent
during its later growth stage, and thepygidium may have variable shapes dueto the presence or absence of the pygidial
spines as indicated earlier by Hu (1970).
Therefore, the specific characteristics ofthe present species need further examination. The Black Hills specimens of
Housia are assigned to H. ovata on thebasis of preservation and the generalskeletal outline.
Housia ovata PALMER
PI. 45, Figs. 1-34 and Text·fig. 5, 6.
Housia ovata PALMER, 1965, p.65, pI. 12, figs.
8-11; KURTZ, 1975, p. 1033, pI. 4, figs. 19,
20.

381

Remarks.- The present species is represented by more than a hundred ofboth large and small skeletons, of which
the largest cranidium is about 8.0 mm inlength (sag.) and the small instars 0.30
mm long (sag.); all show very wellpreserved growth sequences.
The ontogenic development of thepresent species is comparable with thatof H. canadensis WALCOTT, reported fromthe Flathead Formation, Big Horn Mtns.,
Wyoming by Hu (1970), except that thepreservation of the present materials are
better and show the continuous growthseries from early protaspid to the adultforms.
Occutrence.-Galena section, about 5
miles southeast of Deadwood, South
Dakota.
Figured specimens. -GMUC. 43418,
43418a-q, s-z, a'-c'.
Housia ovata PALMER, ontogeny
Metaprotaspid stage (PI. 45, Figs. 1-4
and Text-fig. 5A, B).-The metaprotaspid
shield is round to subround in outline,
convex, and has the pleural and the axial
lobes well differentiated by dorsal furrows,
and is about 0.30-0.35 mm in sagittal
length; the axial lobe is slender fusiform,
tapering both anteriorly and posteriorly;
the axial lobe is made up of a roundfrontal lobe, three pairs of glabellar nodes,
and a round, terminal occipital ring; thelarger specimens have an axis composedof five indistinctly divided segments; apair of distinct pits is present at thesides of the frontal lobe; the supercilioid
ridges are extended from the anterolateral
margin of the frontal lobe, and end in
front of the anterior first glabellar
furrow (tr.); the pleural lobe or the
fixigena is crescentic, convex, and having
the same width as the axis; no marginalborder or furrow is seen. The skeletal

382

Chung-Hung Hu

surface is minutely granulated.
During the present stage, the morphogenesis shows the glabellar nodes fusing
together to complete five axial segments,
the central furrow is absent and the small
occipital segment is distinctly marked off
by a furrow, and is situated at the posterior shield margin.
Paraprotaspid stage (PI. 45, Figs. 5-9
and Text-fig. 5C, E).-The shield is madeof a cephalon and a protopygidium,subround, convex, and well divided into
axial and pleural lobes by dorsal furrows;
the shield varies from 0.40-0.60 mm insagittal length; the cephalon is larger
than the protopygidium, convex, and theslender glabella tapers slightly and isdefined by furrows; the occipital ring isconvex, distinctly separated by a furrow,and with no recognizable median tubercle;
the paired frontal pits are seen, butshallower than in previous stage; theshort eye-brow ridges are extended fromthe anterolateral glabellar segment or thefrontal lobe, and are well separated fromthe palpebral ridge by furrows; theconvex fixigena is about the same width
as the axis; the posterior fixigenal borderis convex, narrow near the glabellar base,and broadens laterally.
The protopygidium is transverse shuttleshaped, narrow, turned-downward from

Explanation of Plate 43
Figs. 1-8. Pseudagnostus communis (HALL & WHITFIELD)
1, 2, two meraspid cranidia, x 28, GMUC. 43413; x 34, GMUC. 43413a.
3-5, three holaspid cranidia. 3, x 16, GMUC. 43413b; 4, x 10, GMUC. 43413c; 5, x 13, GMUC.
43413d.
6, 7, two immature pygidia. 6, x 15, GMUC. 43413e; 7, x 5, GMUC. 43413f.
8, an adult pygidium, x4, GMUC. 43413g.
Figs. 9-12. Homagnostus tumidosus (HALL & WIllTFIELD)
9, an immature cephalic shield; notice the preglabellar depression. x 27, GMUC. 43414.
10, a large sized cephalic shield; notice the preglabellar convexity. x 11, GMUC. 43414a.
11, 12 a small and a larger sized pygidial shield, showing the expansion of the terminal
portion. x 10, x 9, GMUC. 43414b, c.
Fig. 13. Agnostid, gen. et sp. undet. (undescribed). x 6.5, GMUC. 43415.
Specimen was collected from Deadwood Formation, Upper Cambrian, Elvinia zone; Little
Elk Creek, Black Hills, South Dakota.
Figs. 14-32. Pulchricapitus davisi KURTZ
14, a complete metaprotaspid shield; notice the faintly differentiated axial and pleural lobes.
x47, GMUC. 43416.
15-17, three paraprotaspid shields, showing the presence of the protopygidium, and theseparation of the axial ring furrows. 15, x 35, GMUC. 43416a; 16, x 27, GMUC. 43416b;
17, x23, GMUC. 43416c.
18-20, 22, four early meraspid cranidia, showing the development of the preglabellar field.
18, x 21, GMUC. 43416d; 19, x 24, G1VIUC. 43416e; 20, x 23, GMUC. 43416f; 22, x 23,
GMUC. 43416h.
21, 23-25, 31, four late meraspid cranidia, showing the development of the preglabellar field.
21, x 11; 23, x 23; 24, x 25; 25, x 15; 31, x 13. GMUC. 43416i-l, q.
26, a late meraspid librigena. x 10, GMUC. 43416m.
27, a complete holaspid librigena. x 10, GMUC. 43416n.
28, a pygidium. x 23, GMUC. 434160.
29, 30, 32, a few small and large sized cranidia. 29, x 8; 30, x 8; 32, x 14; GMUC. 43416p,
f, s.

Hu:

Plate 43

T?"'ilobite ontogen'ies

2

6

3

4

5

7
8

13

12

9
10

14

16

15
..

18

11

20

· t ......... ~-.·...
a.~·0...,.;'· "' .·'1t,.
._u

,

·

II

-

.

."

21

.:j

.~.~ ,

22

23

24

28

26

30

31

32

720.

Ontogenies of Cambrian T1-ilobites

the posterior cephalic margin, and divided
into two or more segments by welldefined furrows. The skeletal surface isminutely granulated.
In the morphogenesis of the present
stage, the main features are the appearenceof a narrow protopygidium, the glabella
tapers forwardly, the posterior fixigenal
border broadens, and the occipital ring islarger.
Early meraspid stage (PI. 45, Figs. 1115, 17 and Text-fig. 5G).-The cranidium
is trapezoidal in outline, convex, about
0.75-1.25 mm in sagittal length; theglabella is bottle-shaped, expands posteriorly from the first glabellar furrow, andis distinctly delimited by dorsal furrows;
the three pairs of glabellar furrows areA

383

complete; they are faint, shallow, andcurve posterolaterally from the dorsal
furrow; the occipital ring is convex bothposteriorly and vertically, and well-definedby a broad occipital furrow, and bears aminute median node; the anterior borderappears, either with or without a distinct
frontal furrow; the fixigena is the same
width as the glabella or slightly narrower,
convex below the axis, and the narrowwell-defined palpebral lobe is located in
front of the mid-line of the cranidium(tr.); the broad posterior fixigena is triangular, with well defined posterior borderwhich is convex, deeply delimited by abroad border furrow, and less narrowthan the occipital ring (tr.); the skeletal
surface is covered by minute granules.

B

c

H

I

G

J

D

F

E

K

Text·fig. 5. Housia ovata P AL:VIER. A, B, two metaprotaspides, x 41; C-E, three paraprotaspides, x40, x40, x35; F, I, two immature librigenae, x4; G, an early meraspid cranidium,x 22; H, J, two different sized late meraspid cranidia, x 18, x 10; K, an holaspid cranidium withrestored librigena, x 3. (all drawings were made from photographs.)

384

Ch'ttng-H'ttng Hu

The present stage is differentiated fromthe previous instars in that the anteriorborder appears, the palpebral lobe is locatedposterior to the anterior border, the widthof the fixigena is the same as that of theglabella in small form, but becomesnarrower in larger ones.
Late meraspid stage (PI. 45, Figs. 18, 2628 and Text-fig. 5H, J).- The late meraspid cranidium is elongate, trapezoidal in
outline, convex, and has the conicalglabella well-defined by dorsal furrows;
the glabella tapers forward with threepairs of distinct glabellar furrows directednearly horizontally (tr.); the occipital ringis crescentic, convex both vertically andposteriorly, and bears a minute mediannode; the occipital furrow is broad, distinct, and bifurcate laterally; the narrowpreglabellar field is depressed in frontof the glabella, and is connected to the
distinct frontal furrow so as to form a
median niche; the anterior border isnarrowly crescentic with the medianpoint projected both anteriorly and posteriorly, and convex; the narrow fixigena isconvex and has the large horizontal
palpebral lobe located on or near the midline of the cranidium (tr.); the broad
triangular posterior fixigena slopes downward from the dorsal furrow, narrower
than the occipital ring (tr.), and has theposterior border well elevated from thebroad border furrow; the anterior branchof the facial suture line is short, straightdivergently convex; the posterior facial
suture line is divergent laterally andconvex. The skeletal surface is minutely
granulated.
The skeletal development during thepresent stage sees the preglabellar fieldchange from narrow to broad, the median
depression which has been marked on the
preglabellar field gradually disappears,
the palpebral lobe moves backward fromthe anterior mid-transverse line to the
mid-transverse line of the cranidium, andthe fixigena and the posterior fixigenal
area are both reduced in width.
The morphogenesis of librigena (PI. 45,
Figs. 10, 19, 32 and Text-fig. 5F, I, K)
during the different stages sees the ocular

Explanation of Plate 44
Figs. 1-31. Aphelotoxon triangulata, n. sp.
1, 2, two anaprotaspid shield, showing the morphogenesis of the axial lobe. 1, x 52; 2, x 57;
GMUC. 43417, 43417a.
3-5, metaprotaspid shields, showing the slender fusiform glabella and the protopygidium. 3,
x 53; 4, x 56; 5, x 50; GMUC. 43417b-d.
6-10, paraprotaspides, showing morphogenesis of the protopygidium and the glabella. 6,x42; 7, x41; 8, x42; 9, x43; 10, x42; GMUC. 43417e-g.
11-19, several early meraspid cranidia, showing the presence of the anterior border and thecomplation of the glabella. 11, x 35; 12, x45; 13, x 35; 14, x 24; GMUC. 43417j-m. 15,
x19; 16, x26; 17, x29; 18, x28; 19, x32; GMUC. 43417n-r.
20, a nearly complete librigena. x8, GMUC 43417d'.
21-24, several late meraspid cranidia, showing the presence of the narrow preglabellar field.
21, x 20; 22, x 17; 23, x 21; 24, x 22; GMUC. 43417s-v.
25-27, three nearly complete cranidia, showing the absence of the preglabellar field andbroadens of the glabella. 25, x 21; 26, x 24; 27, x 21; GMUC. 43417w-y.
28-31, a few small and large sized pygidia, showing the morphogenesis during their different
growth stages. 28, x12; 29, x12; 30, x8; 31, x4; GMUC. 43417z, 43417a'-c'.

Trilobite ontogenies

Hu:

Plate 44

3

2

4

5

8

7

6

12

20

10
9

14

13

11

15
21

16

17

18

19

24

22

25

26

23

28

•.

'~ ~ .
....
. .:".'"'~~.' .'.. . "f

, .•"'.

.-

27

29

30

:.

.... .

,""~"<.. . .

"

.I.

31

lit

720.

A

Ontogenies of Cambrian Trilobites

B

385

c

D

G

E

F

H
L

K

J

Text-fig. 6. Housia ovata PAUIER. A-F, I, ], a growth sequence of pygidia, showing thethoracic segments and the pygidial morphogenesis, A, x 34, 8-E, x 30; F, x 23; I, x 13;], x 10; G, H,
an immature and mature hypostomata, x 8, x 3; L, K, two different sized holaspid pygidia,
x 9, x 15. (drawings were made from photographs.)

platform increase in width, the occularring becomes shifted from the anterior
to the posterior free margin-the facial
suture line, the genal spine is reduced
from long to short, and eventually disappears.
The morphogensis of the hypostoma (PI.
45, Fig. 16 and Text-fig. 6H, G) during
its different growth stages sees themedian body increase in width, the lateral
marginal spine is absent, the U-shaped
posterior area increases in width andconvexity, and the median posterior
projection disappears.
The growth of the pygidium (PI. 45,
Figs. 20-25, 29, 30, 33 and Text-fig. 6AF, I-L) is as follows: the holaspid pygi-

dium is transversely semicircular to subround in outline, convex, and has 4 to 5
axial rings and a terminal portion;. thepleruallobe is broader than the axis, without a distinct pleural furrow or inter pleuralgrooves; the marginal border is broad
and becomes concave, and is well definedby an inner marginal furrow. The smallest pygidium (Figs. 20, 21) is round andhas 6 or more free thoracic segments andan ankylosed pygidial plate; the lastthoracic segment which lies in front of
the pygidium is the largest one and bears
a pair of long caudal spines, which are
directed posteriorly. The thoracic segments are well impressed by interpleuralgrooves and each ends in a pair of short386

CI,ung-Hung Hu

spines; the pygidial plate lying between
the caudal spines is small, and consists of
2 to 5 ankylosed segments; the marginalborder is narrow.
The morphogenetic sequence of thepygidium the anterior margin of therudimentary pygidium gives up thethoracic segments, and simultaneously theposterior margin of the pygidium gains
a pygidial segment; lastly the pygidial
segments ankylose to complete a holaspid
pygidium; the holaspid pygidium may
also be modified by a broadening of thepygidial margin, by increase in pygidial
size, and the reduction of the free thoracic
segments.
Remarks.- The morphology of the latemeraspides of the present species isclosely similar to that of the genera
Crepicephalus (i. e., C. deadwoodensis Hu,
1971) and Coosia (i. e., Coosia longocula
PALMER, 1965). This might suggest thatthe genus Housia possibly evolved fromthe coosiid group.

References
FREDERICKSON, E. A. (1949): Trilobites faunaof the Upper Cambrian Honey Creek
Formation. jour. Paleont., vol. 23, no. 4,
p. 70-72.
HALL, J. and WlIITFIELD, R. P. (1877): Paleontology: U. S. Geol. Expl. 40th Parallel
Rept., vol. 4, p. 199-23l.
Hl', C. H. (1964): The ontogeny and dimorphism of Welleraspis lata HOWELL (Trilobita). jour. Paleont., vol. 38, no. 1, p.
95-97, pI. 24.
- - (1968): Notes on the ontogeny andsexual dimorphism of Upper Cambriantrilobites of the Welleraspis faunule from
Pennsylvania. jour. Nanyang Univ., vol.
2, p. 321-357.
- - (1969): Ontogeny and sexual dimorphismof three Upper Cambrian trilobites. jour.
Nanyang Univ., vol. 3, p. 438-462.
- - (1970): The ontogeny of Panumia
obscura (LOCHMAX) and Housia canadensis(W ALCOTT) (Trilobita) from the Upper
Cambrian of the Big Horn Mountains,
Wyoming. Trans. Proc. Paleont. Soc.
japan, N. S., no. 77, p. 253-264.
- - (1971): Ontogeny and sexual dimorphismof Lower Paleozoic Trilobita. Palaeonto-

Explanation of Plate 45
Figs. 1-34. Housia ovata PALMER
1-4, four complete metaprotaspides, showing the well preserved glabellar lobes and thecomplation of the glabellar segments. x 41; GMUC. 43418, 43418a-c.
5-9, a few paraprotadpides, showing the presence of the protopygidium. 5, 6, x40, GMUC.
43418d, e; 7-9, x 35, GMUC. 43418f-h.
10, 19, 32, three different sized librigenae, showing the reduction of the librigenal spine.
10, 19, x 4; GMUC. 43418i, s; 32, x 3; GMUC. 43418g'.
11-15, 17, several early meraspid cranidia. 11, x 23; 12, x 25; 13, x 21; 14, x 22; 15, x 15;
17, x 19. GMUC. 43418k-n, p.
16, a broken hypostoma. x7, GMUC. 434180.
18, 26-28, four late meraspid cranidia, showing the presence of the preglabellar field and thenarrowing of the fixigena. 18, x 18; 26, x 13; 27, x 10; 28, x 10; GMUC. 43418q, z, aI, ct.
20-25, 29, a growth sequence of the pygidium, showing the presence of the thoracic segments
during their different growth stages. 20, x 34; 21, x 34; 22, x 20; 23, x 22; 24, x 15 ;25, x 13; 29, x 15; GMUC 43418t-y, d ' .
30,33, two nearly complete holaspid pygidia. 30, x9; 33, x2.5; GMUC. 43418e', hi.
31, 34, two nearly complete cranidia. x 3.5; x4; GMUC. 43418f', i'.

Hu: · Trilobite ontogenies

Plate 45

2

4

3

5
6

12

11

8

13

14

16

15

18

20

19

7

17

21

26

23

24

25

27

28

29

30

31

32

33

34

720.

Ontogenies of Cambrian Trilobitesgraphica Americana, vol. 7, no. 44, p.31126.
""- (1975): Ontogenies of four species ofsilicified Middle Ordovician trilobites from
Virginia. Proc. Ceol. Soc. China, no. 18,
p. 115-127, 2pls.
- - (1979): Ontogenic studies of a few
Upper Cambrian trilobites from the Deadwood Formation. Trans. Proc. Palaeont.
Soc. Japan, N. S., no. 114, p. 49-63.
KOBAYASHI, T. (1935): The Cambro-Ordovician formations and faunas of South
Chosen. Palaeontology, Part 3. Cambrianfaunas of South Chosen with a special
study on the Cambrian Trilobite genera
and families. Jour. Fac. Sci., Imp. Univ.
Tokyo, sec. 2, vol. 4, part 2, p. 49-344,
pis. 1-24.
KuRTZ, V. E. (1975): Franconian (Upper
Cambrian) trilobite faunas from the Elvins
Group of south-east Missouri.
Jour.
Paleont., vol. 49, no. 6, p. 1009-1043.
LacHMAN, C. (1959): Treatise on Invertebrate
Paleontology (Part 0) Arthropoda. Geol.
Soc. America & Kansas Univ. Press. 560
pp.
LOCIIMAN, C. and Hu, C. H. (1960): Upper

387

Cambrian faunas from the northwest Wind
River Mountains,Wyoming (Part 1).
Jour. Paleont., vol. 34, no. 5, p. 793-834,
pis. 95-100.
PALMER, A. R. (1955):
Upper Cambrian
Agnostidae of the Eureka district, Nevada.
Jour. Paleont., vol. 29, no. 1, p. 86-10l.
- - (1960): Trilobites of the Upper Cambrian Dunderburg Shale, Eureka district,
Nevada. Ceol. Surv. Prof. Paper, 334-C,
p. 53-107.
- - (1962): Clyptagnostus and associatedtrilobites in the United States.
Ceol.
Surv. Prof. Paper, 374-F, 47 p.
- - (1965): Trilobites of the Late Cambrianptericephaliid biomer in the Great Basin,
United States. Ceol. Surv. Prof. Paper
493, 101 pp.
WALCOTT, Ch. (1924): Cambrian geology andpaleontology V. no. 2, Cambrian andLower Ozark ian trilobites. Smith. Misc.
Coll., vol. 75, no. 2, p. 53-60.
- - (1925): Cambrian geology and Paleontology V. no. 2, (Cambrian and Lower
Ozarkian trilobites). Smith. Misc. Coll.,
vol. 75, no. 3, p. 61-147.

m!l'::r!J Deadwood liti£ETQ) 7J :/ -7 V 7*,cfii::)tJj::::~!R.Q)fflil{i$:§e~ : *$15t;:::t~\"-Ot, ::::~!R. 3:fiR,

7 !l' J A!J AM 2 :fiR(1)m{i$:§e~ Z'~~ilc~-t:Q. -ttJ:b'l?, ii1J~lt Aphelotoxon triangulata, n. sp.,
Pulchricapitus davisi KURTZ, Housia ovata PALMER '"C;l; lJ, f~~lt Pseudagnostus communis(HALL and WHITFIELD) ;foJ:a Homagnostus tumidosus (HALL and WHITFIELD) '"C;l;:Q. ':'nI?Q)
tH4It-t-"'-Cm!J"::r !J ~1'1Q) 7J :/ -7 V 7*,cf;!i::)tJjQ) Deadwood lit Elvinia *7.J' I?~ I?nt-: t Q)'"C;l;:Q 7.J', ii1J 3~t;::"':J\' '-Cltjti\OC(~J~ <flIf~ ~nt-: t Q)Q), f;!i: 2 ~t;::~ L- -Clt~.1. /f%~'"C;l;:Q. flIf~Q)k:5*, Aphelotoxon
triangulata Q)*Ri1t§e~7.J; Ponumia, Housia tJ:I?at;:: Cliffia -*~t;::, "£t-: Palchricapitus davisi O)-tn7.J' Coosina ;fo J: V~ Wilsonella ~t;::i!lJ!l'"C;l;:Q':' C 7.J;!Jij I?7.J' c tJ:"'? t-:. Housia ovata Q)1~:)tJj~~lt;fo-t
I? < " - ~ :7 M Q);l; :Q t Q) -{7U;t Ii Coosia longocula PALMER ;l;:Q \" It Coosella convexa TASCH tJ: C-7.J'I?nxl&, Etl* u-: t Q) c~;t I?n:Q.
MIt',@:

Trans. Proc. Palaeont. Soc. japan, N. S., No. 119, pp. 388-402, pis. 46-49, September 30, 1980

721.

A NEW SPECIES OF INOCERAMUS (BIV AL VIA) FROMTHE UPPER CRETACEOUS OF HOKKAIDO*MASA YUKI NODA
Wasadahigashi junior High School, Oita, 870-11

KIKUO MURAMOTO
Mikasa Museum, Mikasa, Hokkaido, 068-22

Abstract. In this paper a peculiar new species of Inoceramus is described on aset of specimens from the lower part of the Middle Turonian of the Obira area,
northwestern Hokkaido. It belongs to the group of I. (1.) lamarcki PARKINSON andis somewhat allied to I. (1.) paralamarcki EFREMOVA, from the Ust. Yenisei depression (USSR), but is distinguished by its extremely high outline, extraordinary convexity, well developed and somewhat convex posterior wing and less inequivalveness.
The occurrence of this kind of inoceramid species is rather unusual in the Upper
Cretaceous of japan and its palaeo biogeographical and evolutionary implications are
discussed in an Appendix by MATSUMOTO and NODA.

getting a few more specimens. One ofus CK. M.) further continued the field
work, with a result to obtain still more.
These are the basic material of the~present
study. The holotype is registrated at
Kyushu University (GK) and others at
Mikasa Museum (MC).
As the specimens are very peculiar ascompared with the better known species
which occur commonly in the Upper
Cretaceous of japan, a biometric examination is added for careful comparison
with the species home and abroad.
After the palaeontological description,some remarks are given on the phylogenetic relations and palaeobiogeographic
implications as an appendix.
In this study NODA is mainly responsible
for the palaeontological description, but
as MURAMOTO has much co-operated in
the field and laboratory works, the co-

Introduction
In the course of restudying inoceramidsfrom the Cretaceous of japan, which oneof us CM. N.) is undertaking, sometimes
with T. MATSUMOTO or others, it isnoticed that there occur occasionallyseveral species which have been little
known from the japanese province. In
this paper one of them is described undera new specific name.
This unexpected discovery came fromour fossil hunting in the Obira area on
August 10th, 1977, when only two valvesof probably a single individual wereobtained. Having been encouraged by
Prof. T. MATSUMOTO, we reinvestigatedthere again in the summer of 1979,* Received May 15, 1980; read Oct. 14, 1978
at Yamagata.
388

721.

A new species of Inoceramus

authorship is taken.
Before going further, we thank Emeritus
Professor Tatsuro MATSUMOTO of Kyushu
University for his cordial help and advice,including critical reading of the firstdraft. We are indebted to Mr. Kinichi
KAMIZUMA and Mrs. Tomiko SUGA w ARA
for their help in the field work.
Furthermore, one of us (M. N.) isindebted to Prof. MATSUMOTO who has
co-operated in the discussions of thephylogeny and palaeobiogeography.
Notes on Stratigraphy
The Obira area in northwestern Hokkaido
is famous for the well exposed Cretaceoussequences and occurrence of well preserved
fossils. Aside from the classical works
of JIMBO (1894) and YABE (1909), the389

Cretaceous stratigraphy of this area has
been recently described by TANAKA (1963),
MATSUMOTO et al. (1976-issued 1978) and
TANABE et al. (1977) among others, withlists of fossils from the subdivided units.
Geological maps by TSUSHIMA et al. (1958)
and IGI et al. (1958) are also available.
The present discovery of a new species
happened to come from our hunting offossils in the Zone of Inoceramus (1.)
hobetsensis (Middle Turonian).
Four localities grouped into two areconcerned with the basic material. Theirlocations are indicated in the route mapsof Text-figs. 1 and 2 and also recorded
as follows:(1) Lac. Ob1010: Osarunaidake Quad. (Topographic Map 1: 25000). Long. 142°0'22"E,
Lat. 44°03'49"N. 108 Rinpan-no-sawa, about
400 m upperstream from the confluence with

1018

'C?'7

101'

tOtSP
I025P

1009

IOl9p
1022

10268

1023

1005

IOOlP
100JP

1026b

1028b

102811

1029

Text-fig. 1. Locality map of Inoceramus (Inoceramus) obiraensis n. sp. (108 Rinpan-no-sawa).
For the index map refer together with that of the Text-fig. 2.

Masayuki NODA and Kikuo MURAMOTO

390

If

,f
VlhV'U Oblrash1bll-~..-::;:;

~~7··
~
If"

2.63

..

~.

'0·2

"\

.

.

2052
2041
2048

2.39'
INDEX MAP 2

ZQ43

,~~~
..·.0.•

....

2.38.

~_
~

2.61

.~
~...

ZOS3P

2054

!\

2:::.

2056P

2058P

2.37

2~.59P

0,

t

\

~r

19011\

Text-fig. 2. Locality map of Inoceramus (Inoceramus) obiraensis n. sp. (Nanbu-no-sawa).
For the index map refer together with that of the Text·fig. 1.

Sato-no-sawa, a branch of Kamikinenbetsuzawa, a tributary of the River Obirashibe,
administratively in Kamikinenbetsu, ObiraMachi, Rumoi-gun, Hokkaido.
(2a) Loc. Ob2049: Takishita Quad. (Topographic Map 1: 2S000). Long. 141°S6'391/E,
Lat. 44°03'491/N. Nanbu-no-sawa, a tributaryof the River Obirashibe, about 800 m upwardfrom the confluence with the main stream of
the Obira, along the course of stream.
(2b) Loc. Ob20S0: Takishita Quad. (Topographic Map 1: 2S000). Long. 141°S6'411/E,
Lat. 44°03'491/N. Nanbu-no-sawa, about SO m
upperstream of Loc. Ob2040.
(2c) Loc. Ob2060: Takishita Quad. (Topographic Map 1: 2S000). Long. 141°S6'321/E,
Lat. 44°03'S41/N. Nanbu-no-sawa, about ISO m
downstream from Loc. Ob2049.

As has been described by aforementioned
previous authors these localities arewithin the area of the Middle Yezo
Group. This group in the Obira area issubdivided into 15 units, from Ma to Mo
in ascending order.
(1) Loc. Obl0l0 is situated within Unit
Mj in the published geological map of
TANAKA (1963, map 1), but according to
MATSUMOTO (personal comm.), who investigated there with K. MURAMOTO onother days, there is a thrust at somedistance on the west side of the locality,
by which Unit Mk seems to reappear
there. Unit Mk is characterized by thecommon occurrence of an inoceramid,
which is temporarily called I. CI.)
aff. hobetsensis nonsulcatus NAGAO et

721.

A new species of Ino ceTa1n~~S

MATSUMOTO,
andEubo strychocems
japonicum (Y ABE) (emended by MATSUMOTO, 1977) and other heteromorphammonoids. Lithologicall y clay is predominant in Mj, whereas sand y siltstone
is so in Mk. It is highly possible thatthe inoceramid specimens obtained at
Ob1010 came from Unit Mk, and accordingl y lower part of the "Middle Turonian"[K4b z of MATSUMOTO, 1980 in press] on
the Japanese scale.
(2) Locs. Ob2049, Ob2050 and Ob2060
are in the limited part of the lower
course of the Nanbu-no-sawa, a tributaryof the River Obirashibe, which Unit Mk,
MI and Mm are indicated in the pubished391

geological map of T A 'AKA (1963, map 1).
Loc. Ob2050 is certain ly within Unit Mk,
but nodules at Locs. Ob2049 and Ob2060
are floats derived from some exposuresin the upstream and their stratigraphic
assignment to Unit Mk is presumed fromthe associated I. aft. hobetsensis nonsulcatus as well as their somewhat downstream position as compare w ith Loc.
Ob2050.

Method of Examination
The basic morphology for measurements
is shown in Text-fig. 3.
Calipers of JIS standard, 200 mm in~ f--HLh

Text·fig. 3. Basic morpholog y fo r meas ur ements. l: shell le ngth, h : s hell he ight, 1-1L:
hinge·line, T : t hi ckness, ga: growth axis, H: ma x imum dim ension from umbo to ve ntral ex ·t remit y, a: angle betwee n a nterior margin and hinge·l ine, f3: beak a ng le, (j: obliquit y- ang lebetween hin ge·line a nd H, or at a ce rtain g ro wth stage of gao

392

Masayuki NODA and Kikuo MURAMOTO

measurable extent and 1/20 mm in accuracy, and contact goniometer were used
for measurements of length and angle
respectively. A flexible gauge was applied
for measurements of the vertical and crosssections of ontogeny. Measurements are
made three times for the same part, andthe mean values are shown.
The process of the numerical analyses
and calculations are omitted. For details
readers may refer to HAYAMI (1969), and
HAYAMI and MATSUKUMA (1971).
Palaeontological Description

Family Inoceramidae GIEBEL, 1852
Genus Inoceramus SOWERBY, 1814
Subgenus Inoceramus SOWERBY, 1814
Inoceramus (Inoceramus) obiraensis
NODA et MURAMOTO, sp. nov.
PIs. 46-49

Material.-Holotype. GK. H10107, separate valves of a single individual, whichmust have been articulated originally,
from Loc. Ob101O, probably Unit Mk of
the Middle Yezo Group (obtained by M.
NODA and K. MURAMOTO, 1977). Paratypes. MC540827, left valve from Loc.
Ob2049: presumably middle or upper partof Unit Mk (obtained by K. MURAMOTO,
1979), MC540728, right valve from Loc.
Ob2050: middle part of Unit Mk (obtainedby joint field work of M. NODA, K. MURAMOTO, K. KAMIZUMA and T. SUGAWARA,
1979) and MC540729, left valve from Loc.
Ob2060, middle or upper part of Unit Mkof the same group (obtained by M. NODA,
K. MURAMOTO, K. KAMIZUMA and T.
SUGAWARA, 1979).
Diagnosis.-Shell of medium size, inequivalve, extremely strongly convex
antero-posteriorlyand also dorso-ventrally.

Umbo terminal, less conspicuous, projectedbeyond the hinge-line, and curved inwards
and a little forwards. Anterior side verybroad and concave to the valve plane,
posterior one also steep or truncated anddemarcated clearly from the posterior
wing, which is considerably wide andinflated dorso-ventrally. Right valve lessconvex than left, but its wing is more
inflated than that of left valve. Anterior
margin straight or slightly concave,antero-ventral one broadly round, ventral
margin narrowly rounded, passing into
broadly arcuate postero-dorsal margin.
Hinge-line somewhat shorter than two
thirds of shell length.
Surface ornamented with concentricribs and rings in combination. The concentric ribs coarse, round-topped, regularin strength and size in the middle stage,then becoming irregular and separated bysomewhat wider and concave interspaces.
The concentric rings cover the ribs andinters paces. The ribs much weakened on
the anterior part and also on the posterior
wing where only concentric rings are
discernible. Hinge-structure unknown.
Measurements.-See Table l.
Ontogeny.-The
individual
relative
growth of the holotype is examined separately for the left and the right valves.
The three variables, height (h), length(1), and thickness (T) of each valve are
examined.
Plotting I and T in the ordinate and hin the abscissa on logarithmic graphpaper, and the reduced major axes arecalculated (for the calculation refer to
HAYAMI and MATSUKUMA, 1971). The
relative growth of I and h, and I and T
are shown in Text-fig. 4. For comparison, those of I. (I.) hobetsensis
nonsulcatus collected from the same area
are shown.
The ontogenetic changes of characters
are also illustrated in Text-figs. 5A, B

A new species of Inoceram~ts

721.
Table 1.

393

Measurements. linear dimension in mm.

Specimen

1

h

I

T

HL

{j

'}H=60 mm

I

58.0

44.5+

72

80

68

86

74

82

------=1=

GK.H10107 RV

73.3+

137.7

GK.HlOl07 LV

59.1+

107.3+MC540728 RV

39.4

65.5

-1- 26.9 i 24.6

MC540729 LV

31.9+

60.0

I

MC540827 LV
Specimen

64.6

I

I

25.4

100.3
l/h

1/h=60 mm

GK.I~10i07-RVr;~53+-1

0.76- GK-:-I-IlO107 Ly-!-0:55---:- ()-.64~-MC54-07-28-RV-il~0.60 ·--1;-- 0.64~-MC540729 LV!

II-O.-53~---MC540827 Lv-II~----'I--

0.53+
-

r

47.2
T/h

0.~2

-

0.60-

1-

i 0.42-----I-

r

64

HL/h

h/1

T/1

: HL/l

0.32+

1.88-

0.79-

I

0.61

1. 82

1.09-

0.38

1. 73

0.68

1

0.62

-

1.88-

0.8~-_J -i

OAl--i

59

i

l _=-

O.-47~ _..

1: shell length. h: shell height. T: thickness. HL: hinge-line. f3: beak angle.
angle between hinge-line and H, at a growth stage of 60 mm in H. GK: specimensof Kyushu University. MC: specimens of Mikasa Museum. LV: left valve. RV: right valve.

reference.
OH=60 mm:and 6A, B. As are clearly shown in
Text-figs. 4 and 6, in the juvenile stages
the specimens closely resemble those of
I. (I.) hobetsuensis nonsulcatus but aremuch more inflated antero-posteriorly andalso along the growth axis, and considerably elongate along the growth axis.
Descriptive l'emarks.-In the holotype,a portion of the posterior wing is erodedout at the marginal part, thus the simple
ratios of I/h and HL/h of each valve
may be slightly larger than the value
shown in Table 1. The left valve of theholotype is also somewhat eroded out
from the flank to the venter and thehinge part, the values of T Ih and T /1,
therefore, may be somewhat smaller thanthose shownin Table 1. MC540729isdeficientin the posterior half and hinge part andMC540827 is so at the umbo and wing.
The test, which remained on MC540728

and MC540827, is fairly thick near theumbo, where the surface sculpture is
precisely observed. On the surface of theinternal mould, faint radial striae are discernible in the anterior part, where concentric ornaments disappear. The beakangle and the shell convexity vary
among individuals. For example, MC540827
has much stronger convexity than otherspecimens, although it is impossible toexpress numerically.
Comparison
I. (1.) lamarcki PARKINSON, a widespread
species of the Middle to Upper Turonian,is considerably variable in outline andshell convexity (WOODS, 1912a; TROGER,
1967). Some specimens of that species
somewhat resemble the present specimens
in the elongate outline along the growthMasayuki NODA and Kikuo MURAMOTO

394

Imm
.00
90
80
70
60
SO

B

A

CD

Tmm
.00
90
80
70
6O
so

1= 2.005ho. 737
r=0.9931@

1= 1. 175h o.89s

1=0.993hO.S9 •

(i)

30

20

20

so

70
60
so

r=0.9967
1= 0.933 hO. 93 •

40
30

Tmm
.00
90

Imm

r= 0.9996

,
,,
,~

/

30

/

/

20

~

;'

r = 0.9868
@

.~,~

.0
9
8

.'

T =O.369ho. 901

1'"

,"

,/'

T=0.165~·230.09

r=0.9914@

T=O. 2 72 hl. 006,(

r =0.9927/'

r=0.9972

~
20

30

40

50 60708090100

h mm

20

30

40

SO 60708090100

h mm

Text-fig. 4. Diagram showing the individual relative growth. A: right valve, B: left valve
1, 3: I. (1.) obiraensis, solid line, 2, 4: I. (1.) hobetsensis nonsulcatus, broken line.

Text-fig. 5.

Ontogenetic change of shell convexity.

axis and well developed wing. JUdging
from the illustrations and a plaster cast
(GK. H9586) of WOODS (1912a, pI. 213, fig.
66, BM4753; 1912b, p. 8, figs. 34-36), awell inflated specimen has a smaller proportion of hll, and other specimens with
an elongate form are highly inequivalve.
Our specimens are still more elongatedand more convex and less inequivalve
than any illustrated examples of I. (l.)
lamarcki. TROGER (1967) examined biometrically some characters of I. (l.) lamarcki

A: anterior view, B: dorsal view.

lamarcki from the Middle Turonian ofSachsen and Harzvorland, East Germany,
showing them in p. 189, text-fig. 16a, b,
for the left and the right valves respectively. As is clear from Text-fig. 6a, theontogenetic change of the simple ratio
llh of the holotype of our species agrees
well with that of I. (l.) lamarcki lamarcki
var. I in the right valve, but never inthe left valve. TROGER did not demonstrate the ontogenetic change of T Ih,
which should be more effective to721.

A new species of Inoceramus

395

l/h
%

A

100
90
80
70

.. _- ... .... ".----.--...
- ,

,-

.

- -----------

MC520810l

60

MC520810R
-0

10

20

30

40

50

60

70

80

90

100 110120130 hmm

T/h
%

B

70
60

--

...... .,. ..

/_ MC520810l

~

50
40

....,

30

10

20

"..--/
30/.-....-- ...... --... --40

50--- --

60

70

~

~

~

-- --

--~

0

MC520810R

80

90

100

110 120

Text-fig. 6A. Diagram showing the ontogenetic change of simple ratio l/h.
showing the ontogenetic change of simple ratio T /h.

compare the two species. The shell convexity of the TROGER'S specimens is also
considerably strong in both valves, so far
as his illustration (p. 61, fig. 16) is concerned.
As has been kindly suggested by MA TSUMOTa (personal comm.), the holotype ofI. (I.) paralamarcki EFREMOVA (1978, p.
82, pI. 1, fig. 1), from the lower part of
the Nasonovsk Formation (Zone of 1.

130 hmm68.

Diagramlamarcki) of the Ust-Yenisei depression,
resembles the present species in obliquity,shell convexity and sharply demarcatedposterior wing. But the former is discriminated from the latter in its more
remarkable inequivalveness, smaller proportion of hll, shorter and less inflated
wing and much weaker concentric ornamentation.
As has been also suggested by MA TSU-

396

Masayuki NODA and Kikuo MURAMOTO

MOTO (personal comm.), I. (I.) najdini
IVANNIKOV (1979) from the Upper Turonianof the Donets Basin looks similar to thepresent species, so far as his photograph(IVANNIKOV, 1979, pI. 21, figs. 2, 3) isobserved, but distinct from the latter inthe equivalve shell, smaller proportionsof T /1 and h/l and also a smaller triangularwing.
Appendix
Notes on Phylogeny andPalaeobiogeography
byTatsuro MA TSUMOTO* andMasayuki NODA
To evalute the present discovery of apeculiar Inoceramus species of the lamarcki
group from the Turonian of Hokkaido, let
us discuss the phylogeny and palaeobiogeography on the basis of the available
data.
The present species occurred in association with an undescribed form which isprovisionally called Inoceramus (Inoceramus) aff. hobetsensis nonsulcatus andthey agree well in shell-form and ornamentation in their early growth stage.
This suggests some phylogenetic relation
between them, but we found no transitional form which could link the two
species in Hokkaido. The stratigraphic* c/o Department of Geology,
University 33, Fukuoka 812.

Kyushuposition of these species is in a relatively
lower part of K4b 2 of the Japanese scale(MATSUMOTO, 1977), i. e. the lower partof the Zone of Inoceramus hobetsensis.
This zone is correlated with the Middle
Turonian in terms of the international
scale, because it contains Collignoniceras
woollgari (MANTELL). Strictly speaking,however, the boundary of the Lower andthe Middle Turonian is not yet precisely
defined even in France and England (seeHANCOCK et aI., 1977). Be that as it may,the origin of the present species is morereasonably ascribed to the migration from
elsewhere than to the sympatric speciation
within Hokkaido.
Turning to the regions outside theJapanese province, we notice I. (I.) paralamarcki EFREMOVA, from the Nasonovsk
Formation of the Ust-Yenisei depression,
as one of the closely allied species toours. In the same formation of the UstYenisei depression that species is associated with I. (I.) pogrebovi EFREMOVA,
I. (I.) schulginoae EFREMOVA and I. (I.)
kolokolcevoae EFREMOVA. These species
are all ascribed to the group of I. (I.)
lamarcki and occur in the Zone of Inoceramus lamarcki, that is "Upper Turonian"of her concept (EFREMOVA, 1978), which
may include the Middle Turonian ofothers.
I. (I.) pogrebovi among others, looks
similar to I. (I.) hobetsensis nonsulcatusin outline and surface ornamentation. In
her paper, however, the right umbo is
described as being more projected beyond
the hinge-line than the left. This seems

Explanation of Plate 46
Fig. la-c. Inoceramus (Inoceramus) obiraensis n. sp. natural size. Holotype, rg. GK.H10107,
right valve. Loc. Ob10l0, 108 Rinpan·no-sawa, Kamikinenbetsu, Obira machi, Rumoi gun,Hokkaido. Str. position: middle part of the Unit Mk of the Middle Yezo Group. (colI. M.
NODA and K. MURA~IOTO, 1977). a: lateral view, b: anterior view, c: dorsal view.

NODA

and MURAMOTO:

A new species of Inoceramus

Plate 46

721.

A new species of Inoceramus

exceptional for the normal inoceramids:
otherwise the valves may have been
displaced secondarily along the valve plane.
I. (/.) kolokolcevoae is characterized bya very long hinge-line (as long as the shelllength) and an extremely large posterior
wing. A similar form is occasionallyfound as a variety of an associate formof I. (/.) hobetsensis (s. I.) from Unit Mkof the Obira area. In short, it is interesting to note that the assemblage of theabove species in the Nasonovsk Formation
is in harmony with that of I. (/.) obiraensis, I. (/.) aff. hobetsensis nonsulcatus
and I. (/.) hobetsensis (s.l.) in Unit Mk of
the Obira area.
The group of Inoceramus lamarcki isdefined typically by TRaGER (1967). We
follow him, but take the group in a broad
sense, in which both the sulcate and nonsulcate forms are included. We do notregard the sulcate species as a single
lineage (e. g., I. lamarcki lineage of
KAUFFMAN, 1977, p. 177), but sulcate
forms developed probably from nonsulcate
ones in several parallel lineages of thelamarcki group (s. I.).
Now, going westward, MOSKVINA (1959)
recorded I. (/.) seitzi from the "Upper
Turonian" (upper half of Turonian, probably including the Middle Turonian) of
the northern Caucasus. It resembles I.
(/.) obiraensis in the degree of inequivalveness, elongate outline, strongly involved
umbo and broad anterior part, but differs
in its less convexity and smaller triangularposterior wing. TRaGER (1967, p. 60) did
not identify it with true I. (/.) seitzi
ANDERT (1934), from the "Oberturon
a·{3", that is basal Coniacian, of central
Europe, but has assigned it to I. (I.)
lamarcki lamarcki with a query.
I. (I.) najdini IVANNIKOV, from the"Upper Turonian" of the Donets Basin,
Ukraine, is somewhat similar to I. (I.)
obiraensis, as has been discussed in the397

preceding page. In "Turkestan" of the
USSR central Asia, ARCHANGUELSKY(1916, p. 16, pI. 2, figs. 4-6; pI. 3, fig. 1)
described two forms of thelamarcki
group, one of which (1916, pI. 2, fig. 6)
is seemingly similar to I. (I.) obiraensis,
but the precise comparison is difficult because of the deficiency of its posterior
wing and the absence of the right valve.
On the material from central Europe,
TRaGER (1967) discriminated three subspecies and two varieties of I. (I.) lamarcki, that is I. (I.) lamarcki lamarcki var.
I, I. (/.) lamarcki lamarclzi var. II, I. (/.)
lamarcki geinitzi TRaGER and I. (I.)
lamarcki stiimckei HEINZ. As to thephylogenetic relations, TRaGER (1967, p.
134; 1976) remarked that the lineage
would be I. (I.) lamarcki var. I-var. III. (I.) lamarcki stiimckei, which weredecreasing gradually in shell convexity.
He has shown that these subspecies occur
successively one after another with considerable overlapping.
As to the British Middle to Upper
Turonian species of the lamarcki group(s.I.), KAUFFMAN (1978) preliminarily
reported the ascending succession as
follows: (1) I. (I.) cuvieri cuvieri SOWERBY, (2) J. (/.) cuvieri subsp. nov, (3) J. (/.)
jlaccidus WHITE with early J. (I.) lamarcki,(4) I. (I.) costellatus WOODS with early I.
(/.) lamarcki (s. I.) and early I. apicalis
WOODS and (5) J. (I.) lamarcki "plexus"
with I. apicalis. No species comparablewith I. (I.) obiraensis is known in thisarea.
In the Turonian of the North American
Interior province, there are several species
belonging to the lamarclzi group, such as
I. (I.) jlaccidus and "I. (I.) sp. nov. aff. I.
(I.) flaccidus and I. (I.) lamarcki" (KAUFFMAN, 1977b, pI. 8, figs. 11, 16). I. (I.)
jlaccidus resembles in some respects I.
(I.) hobetsensis hobetsensis, as NAGAO and
MATSUMOTO (1939, p. 285) and MATSU-

398

Masayuki NODA and Kikuo MURAMOTO

MOTO (1959, p. 85) have already pointed
out and more recently KAUFFMAN (1977,
p. 177) has remarked. We have noticed,
however, no species among the describedones from this province which is closely
allied to I. (I.) obiraensis.
One of us (MA TSUMOTO, 1978) has
shown a reconstructed palaeogeographic
map of the world for the Early Turonian,
showing the distribution of certain
vascoceratid ammonites of the Tethyanaffinity. In this paper, we show in Textfig. 7 a tentative palaeogeographic map of
the world for the Middle to Late Turonian.
As compared with the Early Turonian,
the epicontinental seas retreated extensively from various areas in the Middle
to Upper Turonian time and the tropical
Tethys Sea became narrower and lesscontinuous. Probably for this and otherreasons the ammonites of the Tissotiidae,
Coilopoceratidae and other Tethys Sea
elements are almost absent in the japaneseprovince. The inoceramids show also a
remarkable change. For instance, world
wide species of the Mytiloides labiatus
group occur fairly commonly in the Lower
Turonian of japan, whereas an apparently
endemic Mytiloides teraokai MATSUMOTO
et NODA remained as a descendant in the
Middle Turonian. Inoceramus species ofthe lamarcki group, such as I. (I.) hobetsensis (s.l.) and I. (I.) iburiensis NAGAO et
MATSUMOTO, occur extensively andabundantly in the Middle Turonian of thejapanese province and its extension. A
possible ancestor of I. (I.) hobetsensis orthat of I. (I.) aff. hobetsensis has not yet
been found from the Lower Turonian ofjapan.
In Text-fig. 7, we show the main areas
where the species of the I. (I.) lamarcki
group have been reported with clear
records. As is evident from this map,
their distribution is limited to the North
Temperate Realm (as defined by KAUFFMAN, 1973). In that realm the North
European Province (la in Text-fig. 7) is
extended eastward to the North Central
Asia Subprovince (lb) and the West
Siberia Province (4) should better be
defined to include the Ust-Yenisei depression. The latter province has alreadybeen indicated by TROGER (1976a) as arepresentative of the Boreal Realm in his
Early Turonian faunal palaeogeographic
map. In the North Temperate Realm,
the North American Interior Province (2)and the North Pacific Province (3) arealso included, the latter of which are
subdivided into the Northeast Pacific (3a)and the japanese-East Asian (3b) subprovinces.
As KAUFFMAN (1973) has generally
stated, some of the species in the North
Temperate Realm may suggest possible
migration routes and patterns. It can bepresumed that the group of I. (I.) lamarcki

Explanation of Plate 47
Fig. la-c. Inoceramus (Inoceramus) obiraensis n. sp. natural size. Ho!otype, rg. GK.H10107,
left valve. Loc. Ob1010, 108 Rinpan-no-sawa, Kamikinenbetsu, Obira machi, Rumoi gun,Hokkaido. Str. position: middle part of the Unit Mj of the Middle Yezo Group (coli. M.
NODA and K. MURAMOTO, 1977). a: lateral view, b: anterior view, c: dorsal view.
Fig. 2a-c. Inoceramus (Inoceramus) obiraensis n. sp. natural size. Paratype, rg. MC540827, left
valve. Loc. Ob2049, Nanbu-no-sawa, Obira machi, Rumoi gun, Hokkaido. Str. Position:
middle to upper part of the Unit Mk of the Middle Yezo Group (colI. K. MURAMOTO, 1979).
a: lateral view, b: anterior view, c: dorsal view.

NOD A and MURAMOTO:

A new species of Inoceramus

Plate 47

721.

A new species of Inoceramus

399

Text-fig. 7. Palaeogeographic map of the Middle to Late Turonian, showing the distributionof the group of I. (/.) lamarcki. (reconstruction after DIET% and HOLDEN, 1970). 1a: North
European Province (proper). 1b: North Central Asian subprovince. 2: North America Interior
Province. 3a: Northeast Pacific subprovince. 3b: Japanese East Asian subprovince. 4: West
Siberian Province.

was dispersed by way of the circum-polar
seas rather than the tropical Tethys Sea.
A question, however, remains unsettled
as to the ancestor of this group. TROGER(1976b) has left blank for the Early
Turonian below the phylogenetic tree ofthe lamarcki group and above that of thegroup of I. tenuis- I. pictus.
Another question is whether the migration took place from the North Pacific
Province via the circum-polar seas to theNorth European Province or vice versa
or from the Arctic Sea to the North
Europe and North Pacific Provinces
simultaneously. To solve this problem
more careful comparison of the species,
further collecting better fossils and more

precise correlation are necessary between
the regions concerned.
Still another question is to find a definite
route of migration among the postulated"circum polar seas".
In view of the recent results of palaeotectonic studies (e. g. MONGER et aI.,
1972; FUJITA, 1978; DICKINSON, 1978),which show general development of themountain systems around the North
Pacific from Jurassic to Cretaceous period,
it seems fairly difficult to point out theactual position of the Turonian seaway
for the inoceramids to migrate between
North Europe or West Siberia and theNorth Pacific through the Arctic Sea. In
Text-fig. 7, a possible route is suggested

400

Masayuki NODA and Kikuo MURAMOTO

through a postulated channel along theYuzhno-Anyuy suture (between the massifsof Kolyma and Chukotka), which thenturned to the Penzhina trough and extended
southward to the trough of SaghaIienHokkaido. We have, however, no positive
evidence of the marine Middle Turonianin the Yuzhno-Anyuy area. The migrationof a group of Inoceramus if ever occurred,
must have been occasional. And such anoccasional migration may indeed havegiven rise to a rare and unusual species
in the subprovince of Hokkaido.
As a working hypothesis we can expect
the ancestral species of the I. (1.) lamarcki
group in a region of relatively uniform(i. e. less variable) conditions, which could
be sought in an oceanic area. Various
species of the I. (1.) lamarcki group
inhabited in respective niches of several
provinces where they may have evolvedin parallel, adapting themselves to somedifferent environments. I. (1.) obiraensis
may have been derived from that unknown common ancestor directly or
undirectly. Its too much convexity of thevalves may be an extreme specializationand the species may have disappeared
without giving rise to a successor.
To sum up, the phylogenetic position
can be presumed to be a dead end offshootderived from the main stock of the I. (1.)
lamarcki group in comparatively earlystage of the evolutionary history of thatgroup.

References
ANDERT, H. (1934): Die KreideablagerungenZachsen Elbe und Jascken. Teil III: Die
Fauna der obersten Kreide in Sachsen,
Bohmen und Schlesien. Abh. Preu. Ceol.
Landesanstait, N. F. vol. 159, p. 1-477,
pis. 1-19.
ARCHANGUELSKY, A. D. (1916): Mollusquesdu Cretace superieur de Turkestan. Mem.
Com. Ceol. Petrograd, [N.S.] livr, 152,i-vi, p. 1-57, pIs. 1-8.
DICKINSON, W. R. (1978):
Plate tectonic
evolution of north Pacific rim. Jour.
Phys. Earth, vol. 26, Suppl., p. 1-19.
DIETZ, R. S. and HOLDEN, J. C. (1970): Reconstruction of Pangea: Break up and dispersion of continents, Permian to Recent.
Jour. Ceophys. Res. vol. 75, p. 4939-4958.
EFREMOVA, V. I. (1978):
Inoceramus ofTuronian deposits of the Ust-Yenisei
depression. In PERGA~IENT, M. A. (ed.):Jurassic and Cretaceous Inoceramus andtheir Stratigraphic Importance. Geol.
lnst. Acad. Sci. USSR, p. 82-98, pis. 1-5(in Russian).
FUJITA, K. (1978): Pre-Cenozoic tectonic
evolution of northeast Siberia. Jour. Ceol.,
vol. 86, p. 159-173.
HANCOCK, J. M., KEKKEDY, W. J. and WRIGHT,
C. W. (1977): Towards a correlation of
the Turonian sequence of Japan with thoseof North-west Europe.
Palaeont. Soc.
Japan, Special Paper, no. 21, p. 151-168.

Explanation of Plate 48
Fig. la-c. Inoceramus (Inoceramus) ,obiraensis n. sp. x 1.1. Paratype, rg. MC540728, rightvalve. Loc. Ob2050, Nanbu-no-sawa, Obira machi, Rumoi gun, Hokkaido. Str. position: middle
part of the Unit Mj-k of the Middle Yezo Group (coli. M. NODA, K. MCRAMOTO, K. KA:VIIZUMA and T. SUGAWARA). a: lateral view, b: anterior view, c: dorsal view.
Fig. 2a-c. Inoceramus (Inoceramus) obiraensis n. sp. x 1.2. Paratype, rg. MC530729, left valve,Loc. Ob2060, Nanbu-no-sawa, Obira machi, Rumoi gun, Hokkaido. Str. position: middle toupper part of the Middle Yezo Group (coli. M. NODA, K. MURAMOTO, K. KAMIZC1VIA and
T. SUGAWARA, 1979).
Fig. 3. Inoceramus (Inoceramus) obiraensis n. sp. x 0.93. Reconstruction of the holotype by
the plaster model. dorsal view.

NODA

and MURAMOTO:

20

A new species of Inoceramus

Plate 48

721.

A new species of Inoceramus

HAYANIf, I. (1969): Mensuration of fossils
and statistics. An example of palaeontological exercise. Sci. Repts. Dept. Ceol.
Kyushu Univ., vol. 10, no. 2, p. 67-90 (inJapanese with English abstract).
HAYAMI, I. and MATSLJKUMA, A. (1971):
Mensuration of fossils and statisticsAnalysis of allometry and variation. Ibid.,
vol. 10, no. 3, p. 135-160 (in Japanese withEnglish abstract).
IGI, S., TANAKA, K., HATA, M. and SATO,
H. (1958): Explanatory text of thegeological map of Japan, 1: 50000. Horokanai (Asahikawa-39) _ Geol. Surv. Japan,
55+ 9pp (in Japanese with English abstract) .
IVANNIKOV, A. V. (1979): Inoceramid species
from the Upper Cretaceous of the Southwest in the East European Platform.
Akad. Sci. Ukraina SSR, 102p., 32pls. (inRussian) .
JIMBO, K. (1894): Beitrage zur Kenntnis derFauna der Kreideformation von Hokkaido.
Palaeontl. Abh. [N. F.], vol. 2, no. 3, p.
1-48, pis. 1-9.
KAUFFMAN, E. G. (1973): Cretaceous Bivalvia.
In HALLAM, A. (ed.): Atlas of Palaeobiogeography, p. 353-383. Elsevier Scientific
Publishing Company. Amsterdam, London,
New York.
- - (1977a): Systematic Biostratigraphic and
Biogeographic
relationships
betweenMiddle Cretaceous Euramerican and northPacific Inoceramidae. Palaeont. Soc. Japan,
Special Paper, no. 21, p. 169-212.
- - (1977b): I1lustrated guide to biostratigraphically important Cretaceous macrofossils, Western Interior Basin, U. S. A.
The Mountain Ceologist, vol. 14, p. 225274.
- - (1978): British middle Cretaceous inoceramid biostratigraphy. In REYNIENT,
R. A. and THOMEL, G. (ed.) : Mid-Cretaceous Events, Uppsala 1975-Nice 1976 Report,
Ann. Mus. d' Hist. Nat. Nice, vol. 4 (for1974), p. N1-N12.
MATSUMOTO, T. (1959): Zonation of theUpper Cretaceous in Japan. Mem. Fac.
Sci., Kyushu Univ., [D], vol. 9, no. 2, p.
54-93, pis. 6-11.
- - (1977): Some heteromorph ammonoids

401

from the Upper Cretaceous of Hokkaido.
Ibid., [D], vol. 23, no. 3, p. 303-366, pis.
43-61.
- - (1978): Atlas of Japanese fossils, no. 50,
Tokyo
(in
295-300, Tsukiji-Shokan,
Japanese) .
- - (1980 in press): Biostratigraphic subdivision of the Cretaceous system in theJapanese-East Asian Province-Definition
and interregional correlation-In KAUFFMAN, E. G. and HATTIN, D. E. (ed.):The North Temperate Cretaceous. Dowden,
Hutchinson & Ross, Inc.
- - , OKADA, H., HIRANO, H. and TANABE,
K. (1976) : Mid-Cretaceous biostratigraphic
succession in Hokkaido.
Ann. Mus.
d' Hist. Nat. Nice, vol. 4, (issued 1978),chapt. 33, 1-6; 10-18.
MONGER, J. W. H., SOUTIIEH, J. G. and GAllRIELSE, H. (1972): Evolution of the Canadian Cordillera: A plate tectonic model.
Amer. Jour. Sci., vol. 272, p. 577-602.
MOSKVINA, M. M. (ed.) (1959): Atlas of theUpper Cretaceous Fauna from the North
Caucasus and Crimea. 304pp., 91pls. Natin.
Sci.-Tect. Press, Moscow (in Russian).
TANABE, K., HIRANO, H., MATSUMOTO, T.
and MIYATA, Y. (1977): Stratigraphy of
the Upper Cretaceous deposits in the Obiraarea northwestern Hokkaido. Sci. Repts.
Dept. Ceol., Kyushu Univ., vol. 12, no. 3,
p. 181-202 (in Japanese with English
abstract) •TANAKA, K. (1963): A study of the Cretaceous sedimentation in Hokkaido, Japan.
Rept. Ceol. Surv. Japan, no. 197, 122pp., 2maps, 3pls.
TROGER, K. A. (1967): Zur Palaontologie,
Biostratigraphie und faziellen Ausbildung
der unteren Oberkreide (Cenoman bis
Turon). Teil I: Palaontologie und Biostratigraphie der Inoceramen des Cenomans
bis Turons. Abh. Staat!. Mus. Mineral
Ceol., vol. 12, p. 13-207, pis. 1-14.
- - (1976a): Zu einigen Problemen der AlbCenoman-U nter-Turon T ran s g res s ion.
Ibid., vol. 25, p. 49-59.
- - (1976b): Evolutionary trends of Upper
Cretaceous Inoceramus. Evolutionary Bioi.,
Praha, p. 193-203.

Masayuki NODA and Kikuo MURAMOTO

402

TSUSHIMA, K., TANAKA, K., MASUNO, K. and
YAMAGUCHI, S. (1958): Explanatory textof the geological map of Japan. 1: 50000.
Tappu (Asahikawa·38), Geol. Surv, Japan
66+8 pp. (in Japanese with English
abstract) .
WOODS, H. (1912a): A Monograph of theCretaceous Lamellibranchia of England. 2,part 8, Inoceramus. p. 285-340, pis. 51-

54. Palaeontogr. Soc. London.
(1912b): The evolution of Inoceramus
in the Cretaceous Period.
Q.J. G. S.
London, vol. 68, p. 1-20.
YABE, H. (1909): Zur Stratigraphie und
Palaontologie der oberen Kreide von Hokkaido und Sachalien. Zeitschr. deutsch.
Geol. Gesell., vol. 61, p. 402-444.

-

Asahikawa 1t[JII,
Horokanai m1JQIA],
Kamikinenbetsu-zawa J:il2f.tJ.llJjR,
Migiichi-nosawa ;ti-O)jR,
Mikasa =!1:,
Nanbu i¥ffiB,
Nanbu-no-sawa i¥ffiB 0) jR,
Obira-machi
IJ\:ijZIUJ,Obirashibe IJ\:ijZ*,
Osarunaidake :IlHfllP'lffi,
Rinpan-no-sawa ;j;j;li[O)jR,
Rumoigun -mJllHm,
Sato-no-sawa fli:iIiO)jR,
Takishita ilttr,
Tappu ;i1;(Ji,Wasadahigashi

1iEH*~twi~tl:fiBElill!*iJ' i?§eJ! ~nt.: l' / -t '7 A .AO)~:fitc:."?\"-C : ~twillO)~tll!ifiB-a-*ll!itc:.mEno 'J\:ijZ*JII
J:j:rJ:mEtc:. ItJ:fiB !Ili:* 7- "" p .=. 7:/ O):tJgllil'lA < ~I±l L -C\" 0 ii', ..:. O):tJg~iJ' i?,,*~ ~nt.:%,At.d~Jm-a­t"? Inoceramus tc:."?\"-C;m~oo *:filt, t!t::W(Jk]tc:.lA< 5t;(JiL. 7- "" P.=. 7 :/J:j:rfiB-a-fl;';~"to I. (I.)0)

alamarcki tc:.Mftl"t 0 ,#'iJ'~ I). c < tc:.~t"/'"' V 7 Yenisei iiiJ [:1 {J£:ll!!0) Nasonovsk II (I. lamarcki 11\')
iJ'i?i£:1±l U.: I. (I.) paralamarcki tc:.ftlt.:,#,iJ'~\"o LiJ' L, -to);;r-~Wl:l1:iJ'-tnl~ c·\"~ 1:0 L < t~ <,jiljjWl:c t tc:.lil1:-.lli:iliihO):n"'ltc:.~);ffijtc:.-.lli: < O)a-c\',o,#,~, ~i?.;z;.iI~"t ..:...s;o*~ <, ~ i?tc:.iJj{ < ~i?~t':IA\".~%i\"~Mit~c·:ffiil"to,#'iI\3H'0)-C, ..:. ..:.tc:.~:fic L-C Inoceramus (Inoceramus) obiraensis 0)1';
O)t c tc:.llG~U,:o 7ilf5l;tc:.~t.:"? -C. VE*O)llGtt~li1f5l;0)::fj~tc:.1JQx. -C, ~:Ilt(JkJtc:.~b-!to~Jttc:."?\"-Clt
fiUWJi¥Jt~=.Fl1l!: c L -C~~i'I'J<Jt~~1lt t lli\.;z;.t.: o ..:. O)%,At~:fiO) B*-CO)i£:l±llt~L\"O)-C, j!£~:fiO)5t;fpt~ E-a-=.FiJ'iJ' IJ c L -C, 7- "" P .=. 7 :/J:j:r:Jt1lO)iI:ll!!:I!I!.~. *:fi0) *~§e1:t~ Etc:."?\',-C *TO)'iIf~-a- ft~-cilit.;z;.
ko*.~:.EH.Z·N*.~~ fta:~*aM·.EH.~

Explanation of Plate 49
Fig. la, b. Inoceramus (Inoceramus) obiraensis n. sp. x 0.93. Reconstruction of the holotype
by the plaster model. a: posterior view showing the convexity of the wing. b: anteriorview showing the radial striae on the surface of internal mould.

NODAand MURAMOTO:

A new species of Inoceramus

Plate 49

403

PROCEEDINGS OF THE PALAEONTOLOGICALSOCIETY OF J AP AN~4l5cMffifU.................. (Rj~) f$Jl~01980~ 6}j 28 B t.:. 1\iij~::k~L'rrtJ:btLt-: tEf71HW~j§t~t.:.:}.;\"-C,?X0)~;g0) A~~7.M~~~tLt-:(1Wc1*mlf) 0[A~~J - / ~~~~, iJi:if?R:-, ~P~~~-, JII
filiij j~, ~§~~IlJI, T~ j'f., ::k~.llJtb.ft t'~IJj(~

Rj, ~UJ'tID.l(-,j]tiJillll~,f$Jljj, 'glJj(11ft,

wn ~ ~*~z, .1Jj( ~ ~mM~a ~Illl, "'EB~~nE (tJJ:1815)

*

[~~~J

~.&*~~,~*?R:=,

7k:iftilf=:: (J.:JJ:

315)
Dj1i*~J~iI!!IIML.T.t'~(115)

Four new trilobites from the Permian ofJapan .... KOBAYASHI, T. and HAMADA, T.
Lower Triassic biostratigraphy in the Salt
Range, Pakistan ................ BANDO, Y.
Triassic bivalves from the Buko limestone
formation .................... TAMURA, M.
Lithiotis :}.; J: v: Cochlea rites (=t?cJ'l., -rfill;/.... '7 *) 0)%1m • nlt:iltf*A' ~fjl§%Jl~ 101m.................................. ~n~;Gjc.~M~X.1i'i"~*:fr~5" .WO)~.~;r5t.:."?\',-c ................ llJ~})1;~ ·li!l~rrb.f~
B *tt~I::Afo~~~(n25@]f11]~7.J~ 1980~6J129 B (B)t.:.jl1ij9;n::k~:E!I[~ffl)l:t.:}.;\',-cg~H€ ~tLt-: (~~~ 120

15)

0::k~M(I9]j+.1i'i**~~5.WO)~.~;r5~,,?\,'-C ........ JlI~})1;~· 1!~l1!iiIl-' UEl'HllB=.~9~ {!i:JII~!tf!{;.&:fr~t1H.:. 'lJ";fjJ"t;o 7-"" - r<P 0) {t.;r5:tiJ(IlX.!:I1. t.:. "? \" -C ................. .
..... .. .. ...... " ..... *!Ilf~Jt=::' wm~RjUII
Some fossil ferns from the Carnic Momonoki
formation, Yamaguchi Prefecture, Japan.............. KIMURA, T. and OHANA, T.
Upper Triassic Parasphenophyllum from
Omine, West Japan. " .................. .
· .. .. .. .. .. .. ... ASA~'IA, K. and OISIIl, T.

r(l9]j -I-;Iff 0) 1o)~ If: ~ 0) J)I,;jX C If 1~ 0) p,:JJW,,!:U· .................. " ... (lltffiliA: "TIiJi?XUIl)
jl1ijj;ilif.~(I9]j+1i'i0)=tlcJ'l.1t.1-,i ............... .
........................ ITIf~IEZ·!Ilfrn~z.
(I9]j-H*O)JiJUi~Mt.:."?\,'-c ............ ~*~f!l;jl1ijj;i1!M (I9]j -1··1*7.J' I? 0) 1'-] illi*13 ~J" iitt:ft fL!1t ....
· ••••••...••...•...•.......•...... i:!ijt!illr-F,I{
jl1ij~II~,m]j+m=O)JjJ(lii.!:l1.ft.fi ............... .
••... .•.. .•..••.. ..•.. liYdH f'!~ • +'III:it¥?Xf!l1• P JI h'W 0) ni&tt'ltifL£i1, ............. ·iliM§'/f,"IE(l9IE(I9]j+1i'i • MrJII1i'iO):r '/ / 1t.;r5 ....... .
• . • • . . . . . . . • . . • • . . . . .. IIliJ 10 Mj jil> l;y;Jt.t ~~~~JrlJl79]j-l-;h"i0)!iJ(IlX.!:I1.1t.Tit.:."?\, '-C ..... .
· . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. *:fr1!f11'af!11(I9]j-I·1i'i!iJ(IlX.!:I1.lo)~rr-~O)J3I.:I~ c Fn'Jff.iA\ ..... .
· . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9' tlttti¥?Xf!r;*cfjt~,!ii;(I9]j-l··1*O)JjJ(IlX.!:I1.ft.;r5 (::1;< '/ I·)· . . . . . . . . . . . . . . . . . . . .. <piK:E=' ~:lc'/il; ::1::1:

TiflW .... '7**.~)IgIff.tt{t.1-;t.:."?\"-C ..... .
· .... " .............. '" ~III.¥i'T]· IMI{,J-*i\i~i%lJIHlI!tf!.CV :li!:~50)*:t1t.;r5t.:."?\"-C ....... .
· .... " .. .. ... IlJ~*i\i~· fIli] FIlr~5!: • ~m.¥'i'T]
On the occurrence of Solenites (Czekanowskia
group) from the Upper Cretaceous Omichidani formation, Ishikawa Prefecture, in
the Inner Zone of Japan ............... .
............ KIMURA, T. and OKAWARA, H .

:Ilt:'EHit=:{:i O)WTiIDWiJili ................ lllijH:iltZ®
:ilt!fi;r5IiJ(1'J>j:1O)F)fil!lJ!Itt;r5 c O)lfi]-fJlflJit;: "?\"-C..............••................ IIliJ*i:lltZD}j\, 'b;<p;o l~l1iiJ j{g ljI'i{1i:t~ J: v:.:t 0) i1i~ J: IJ i.¥::±l i";0 -1/ -t: '7.l.;t,

c .:to){t.f-i)~J'f~i¥J~~ ....

. ................................. !IlfEE~Z
Notes on Inoceramus incertus JIMBO (Cretaceous Bivalvia) from the Upper Turonianof Hokkaido .................... NODA, M.

404
A new record of Barroisiceras (Upper Cretaceous ammonites) from Hokkaido ..... .
................................ MATSCMOTO, T., HIRA:-<O, H. and TAKAHASHI, T.
An interesting species of Baculites from theUpper Cretaceous Izumi Group of Shikoku................................ MATSU~IOTO, T., HASHIMOTO, H. and FURUICIII, M.
1fi'JIIP~f!:IjJ{~f,f.i!?f Nautiloid ~;::'?~'-C ....... .

.................................. il-mJ'Cffj'~:fIJli'h*jJilIik~~O)~1f c 1 / -l! '7 A ;t,{I:1l.................................. ;jljU;lf~~l!lli.*e*" =f-::r;r. J:::;t.. 71'1 0)~:t1!~...... MiIJ1t:J't

Cretaceous fossils from the Otochi area,
Shikoku, I. Geological setting (biostratigraphy) ...................... KOZAI, T.,
KATTO, J., NAKANO, K. and TASI-lIRO, M.
Ditto, II. Upper Cretaceous ammonoids ....
. ......................... MATSUMOTO, T.
Ditto, III. Lower Cretaceous bivalves ..... .
.............. TASI-IIRO, M. and KOZAI, T.
Ditto, IV. Upper Cretaceous inoceramids ..
NODA, M., KOZAI, T. and MATSUMOTO, T.
Ditto, V. Upper Cretaceous bivalves ..... .
. .. .. .. .. .. .. . TASHIRO, M. and KozAr, T.
Ditto, VI. Calcareous nannofossils ......... .
OKAMURA, M., NAKANO, K. and T ASI-IIRO, M.
~1:i1iJ~s!IE*O):Iill:1IX!t\ {I:E~:::. ,?~, -C.. 1t~IW!'::::fl~

Cretaceous Foraminifera from the Nakaminato
and Choshi districts, northern Kwanto ..
.............................. MArYA, S.,
I:-<OUE, Y., I"O!\rA, A. and YAMAMOTO, H.
Cretaceous planktonic Foraminifera from theHimenoura Group ....................... .
........ TAKAYANAGr, Y. and YASUDA, H.
~~~jJL$S!IE*.i!?fE~~::rY/7'7Y?rY •..••.••.•.•/ir'ilN ;Ill;. 133f\;lEz • :k~Sw• • ~50)~~~If-c<KSD*.~*0)~

JR. .••..•.•..•......•.•.. *m~fl~· /ir'ilrn~jtE)IIJ)f.;~7J/I-m~flPJ~gl:::.:toIt;Q;f.- ~ y!l'::z 7
r:j:tO)E~~~{I:E....................... .

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HONDA, Y., KOTAKA, T. and MIZUNO, A.

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Transactions and Proceedings of the PalaeontologicalSociety of Japan

September 30, 1980

New Series No. 119

CONTENTS
TRANSACTIONS
718.

KIMURA, Tatsuaki and TSUJII, Masanori :Early Jurassic Plants in Japan,

Part 1 ... .. . . .. . .. .......... . ... . . ..... . ... . . . ..... .. .. ..... ... . .. . ... 339
719.

T AzAwA, Jun-ichi:

Visean Brachiopods from th e Karaumedate Formation,

Southern Kitakami Mountains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 359
720. Hu, Chung-Hung: Ontogenies of a few Upper Cambrian Trilobites from the
Deadwood Formation, South Dakota . ... . . . .. .. . .. . . ... . .. . ... . . . . . ... . . 371
721. NODA, Masayuki and MURAMOTO, Kikuo :A new Species of I noceramus(Bivalvia) from the Upper Cretaceous of Hokkaido . .. . " ... . . . . . . . .. .. . . 388
PROCEEDINGS . ... ... ..... .. .. .. .. .. .......... ........ ........ .. .... .. .... .. .. 403