ISSN 0031-0204

Transactions and Proceedingsof thePalaeontological Society of Japan
New Series

No.

158

Pa laeontological Society of Japan
June 30,

1990

Co-Editors

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The fossil on the cover is Phillipsia ohmorensis Okubo, an Early Carboniferous trilo_bitefrom the Hikoroichi Formation in the Higuchizawa valley, Ofuna to City, Iwate Prefecture, northeast Japan (Collected by A.Haga, PAt 5766, x3.0; after Kobayashi and
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Trans. Proc. Palaeont. Soc. Japan, N.S., No. 158, pp.439-458, 8 Figs., June 30, 1990

898.

ON HA UERICERAS DE GROSSOUVRE, 1894,
A CRETACEOUS AMMONITE GENUS*TATSURO MATSUMOTO

c/o Department of Geology, Kyushu University 33, Fukuoka 812

partly with collaboration of
SEIICHI TOSHIMITSU
Geological Survey of Japan, Tsukuba 305
and

YOSHITARO KAWASHITA
A 1-5, Chiyoda 2, Tomatsu, Mikasa, Hokkaido 068-21

Abstract. Hallericeras de Grossouvre, 1894 is a well known ammonite genus which
occurs widely in the Upper Cretaceous of various regions. There are, however, three
unsettled problems which are studied in this paper with the results as follows:
I. The type species, Ammonites pselldogardeni SchlUter, 1872 is redefined with designation of GBI. 48 (whose suture figured in the original paper) as its lectotype. This conforms
with the concept of the same species by MUller and Wollemann (1906). H. nodlltllm(SchlUter, 1889) and H. bllszii Wegner, 1905 fall in synonyms of H. pselldogardeni in therevised sense.
II. The sexual dimorphism exists evidently in the well studied species of Hallericeras.
This is demonstrated by excellent specimens of H. angllstum Yabe from Japan acquired by
S.T. and Y.K. and also some more material. In H. angllstum macroconchs are twice (ormore) as large as microconchs in diameter. The apertural margin is distinctly sigmoidal inboth conchs and lappeted in microconchs. H. gardeni (Baily) is likewise dimorphic.
Many of the described specimens of H. pselldogardeni are macroconchs which may attain to
420 mm in diameter, whereas H. mengedensis (SchlUter) is probably a microconch of thesame species.
Ill. The phylogenetic origin of Hallericeras is probably in a subgroup of Plizosia
which has compressed nearly flat-sided whorls and weak or short ribs. The projected shortribs remain on the ventral part of H. antiqllum Collignon, a Coniacian species, whereas anincipient keel occurs in a Turonian species of Plizosia. The two subgenera H. (Hallericeras) and H. (Gardeniceras) can be distinguished by the maintennance or disappearance of theventral or ventrolateral riblets or nodes. They probably reflect the evolutionary stages.
The proposal to combine the Hauericeratinae with Puzosiinae into the family Puzosiidae isapproved.
Key words. Hallericeras pselldogardeni, H. angustum, dimorphism, Plizosia, Hauericeras (Gardeniceras).

'Received May 22,1989; accepted February 28,1990
439

Tatsuro Matsumoto

440

Introduction

Hauericeras de Grossouvre, 1894 is regarded as a well known ammonite genus which
has been reported to occur widely in theUpper Cretaceous (Coniacian to Maastrichtian stages) of Europe, contiguous part of the
USSR, South Africa, Madagascar, India,
West Australia and the regions facing theNorth Pacific.
There are, however, at least three major
problems about this genus which should beproperly solved. First of all, I have a doubt
on the current concept of Ammonites
pseudogardini Sch1i.iter, the type species ofHauericeras. Secondly, the idea of dimorphism seems to have been ignored in thehitherto published papers on the taxonomy
and affinities of Hauericeras. Presence orabsence of the dimorphs, and if present, whatkind of dimorphism exists in the species ofthis genus should be worked out. Thirdly,
the phylogenetic origin of Hauericeras is
uncertain and debatable. On the ground of
the renewed or improved knowledge concerning the above two points and also on otherlines of evidence, I should give a reasonableinterpretation on this problem.
In accordance with the procedures ofresearch, three parts are set in this paper forthe above three problems. I am primarily
responsible for the overall reasoning. In
Part II I invite S. Toshimitsu and Y. Kawashita as coauthors with me.
Part I.

Restudy of the type species(by T. Matsumoto)

The type species of the genus Hallericerasde Grossouvre, 1894 (p.219) is Ammonites
pseudogardeni Sch1i.iter, 1872 (p. 54, pI. 16,
figs. 3-6) as originally designated. This
species was established on several syntypes, ofwhich three of Sch1i.iter's collection should beheld in the Geological and Palaeontological
Institute and Museum, University of Bonn(abbreviated here GBI.). I visited there inJune 1965 and was afforded every facility to
study Schl titer's collection of the Upper
Cretaceous ammonites.
Of the two illustrated syntypes, GBI. 48 wasthere. It is the original specimen whose
sutures were shown by Sch1i.iter (1872, pI. 16,
figs. 5, 6) and the drawing is correct. The
other (ditto, pI. 16, figs. 3,4) was missing anddoes not seem to be traced at present.
Considering the situation mentioned
above, I designate herein GBI. No. 48, fromthe "Quadraten - Schichten" at Otilmen,
Westfalen, as the lectotype of Ammonites
pselldogardeni. This specimen is scarcely
deformed secondarily but its surface is somewhat weathered. It is shown in Figure I and
its dimensions are in Table 1. The measurements conform approximately with those by
Kennedy and Summesberger (1987, p.28).
Anyhow, the specimen is wholly septate and236 mm in diameter at its preserved end. On
the assumption that this is the end of thephragmocone and that the body chamber
occupied 240", the entire shell diameter
would be estimated roughly at 420 mm (U =105 mm, U /0 assumed as 0.25). This size is
the same order of magnitude as a macroconchof a certain species of Puzosia.
The whorl is compressed, with B/H = 0.40
to 0.41, and fairly involute, nearly two thirds(in whorl-height) of the next inner whorl
being overlapped by the outer one. The
expansion ratio of the whorl is moderate,
whereas the umbilicus is fairly narrow (seeTable I).
The outer whorl of the lectotype has several
constnctlOns. They are probably six ofwhich last two are distinct and others are
more or less obscured by weathering. They
are weak, narrow, gently flexuous, i.e. biconcave on sides with two shallow sinuses, andprojected markedly on the venter.
The surface of the lectotype looks smoothon the interspaces between the constrictions,but this may be due to the weathering.
Actually there are on the ventrolateral shoulder several faint nodes which have remained

898.

On Hauericeras

441

Figure 1. Hallericeras pselldogardeni (SchlUter). Lectotype, GIB. No. 48, wholly septate and secondarily weathered. Lateral and frontal views. Ventrolateral dotted zone = shallowly grooved. Scalebar=20 mm. T.M. delin.

from the erosion. There must have beenoriginally a row of small nodes or nodose
riblets aligned on the ventrolateral shoulder.
There is also a very shallowly depressed,
spiral zone inside that row of ventrolateral
nodes. SchlUter (1872) failed to recognize
these characters and later (1899) reported anodulous form as a variety nodutus, which istreated by some subsequent authors as anindependent species, Hauericeras nodutum(SchlUter).
The specimens, from the "Lower Senonian"of Braunschweig and Broitzem, describedunder Hauericeras pseudogardeni (SchlUter)

by MUller and Wollemann (1906, p. 14, pI. 4,
fig. I ; pI. 8, fig. 3) are essentially similar tothe lectotype in the fairly involute, highwhorls, weakly marked and gently flexuous
constrictions and a ventrolateral row of
obliquely set, nodose riblets which occur
clearly in the last septate whorl. As theauthors remarked, the appearance of the ornament may vary owing to the state of preservation. There may be also an original variation. I agree with them in regarding H.
nodutum as a synonym of H. pseudogardeni.
One of MUller and Wollemann's specimens(ditto, pI. 4, fig. 1) preserves the beginning of

Tatsuro Matsumoto

442
Table 1.
Specimen (Position)
Lectotype"

Sch. 16,3-4

Measurements of Hauericeras pseudogardeni (in mm).
D

U

H

B

B/H

H/h

Inv.
0.63

(E)

236.0 (I)58.0 (.25)

101.0 (.43)

c. 41.0 (.17)

0.41

1.31

(E-130')195.0 (I)46.0 (.24)

88.0 (.45)

35.5 (.18)

0.40

1.44

-

(E)

252.0 (I)73.0 (.29)

102.0 (.40)

42.0 (.17)

0.41

1.32

0.66

Sch.40,9(E)73.0 (I)21.0 (.29)

30.0 (.41)

-

-

1.36

0.67

M. and W.4, I(E)

230.0 (I)48.5 (.21)

106.0 (.46)

-

-

1.42

0.76

D= diameter, U = width of umbilicus, H = whorl-height, B = whorl-breadth, h= whorl-height at 180'
adaptically from H, Inv. = involution = overlapped part/H of next inner whorl, c.=approximate, E=
preserved end, Sch.16, 3-4=SchIUter, 1872, pI. 16, figs. 3-4; Sch.40, 9=ditto, 1876, pI. 40, fig. 9 as
Ammonites mengedensis; M. and W. 4, I = MUlier and Wollemenn, 1906, pI. 4, fig. I ; These three aremeasured and calculated from the figures. The last one is so much compressed secondarily that theoriginal form may have been modified to some extent, e.g. U narrowed and H enlarged.

the body chamber, where it is 263 mm indiameter. Therefore, its complete shell musthave been very large.
The missing syntype illustrated by Schliiter(1872, pi. 16, figs. 3-4) is described as 252 mm
in diameter at the preserved end, that is also
the beginning of the body chamber. It musthave been also very large, when it was in acomplete state. The last three constrictions
on the late part of its septate whorl are illustrated to be well marked and rather simply
concave without flexuosity but the earlier
ones look weak, narrow and very gently
flexuous. Unless the actual specimen andothers from the type locality are examined, I
would avoid to decide whether it can be
included in the variation of H. pseudogardeni or not.
In view of the undoubted evidence ofdimorphism in a species from Japan (described in Part II), I should regard the above
described lectotype and other large specimensof H. pseudogardeni as macroconchs. Then,
how are microconchs of this species?
In the Museum of the University of Bonn,there was a small specimen from the"Emscher-Mergel" of the Alstaden Mine,southern Oberhaus, described under Ammonites mengedensis Schliiter (1876, p. 154, pi.
40, fig. 9). It is secondarily compressed andits right side is embedded in the rock matrix.
It preserves the body chamber for about 220·,

but its very apertural margin is not shown.
It is only 73 mm in diameter but its measured
proportions of U/D, H/D, H/h and involution are essentially similar to those of H.
pseudogardeni (see Table 1). The constrictions of the actual specimen are not so deeply
marked as those expressed by Schliiter's drawing but narrow, weak, gently flexuous on themain part of flank and markedly projected on
the ventral part like those of H. pseudogardenio Moreover, there are faint, ventrolateral riblets in the late part. This character wasagain overlooked by Schliiter. I suggest that
this specimen may be a microconch of H.
pseudogardeni.
H. buszii Wegner, 1905 (p.208, pi. 8, figs.
la, Ib), from the "Granulatenkreide" at several localities in western Miinsterland, wasoriginally described as closely allied to H.
pseudogardeni and only distinguished by thepresence of ventrolateral riblets or nodes.
The latter species (i.e. H. pseudogardeni) is
now revised to be characterized by the presence of ventrolateral nodes and/or riblets.
In the illustrated specimens of H. buszii, theconstrictions are narrow and gently flexuous
on the main part of flanks, passing to amarked projection on the ventral part, as in
the lectotype and MUller and Wollemann's
specimens of H. pseudogardeni. Wegner's
illustrations show the frequent constrictions,as in H. mengedensis, which also has

898.

On Hauericeras

ventrolateral riblets, as I mentioned above.
H. buszii was established on fairly numerous specimens, of which an example is recorded as very large (0=420 mm), showing at theperistome a projected ventral rostrum and a
distinctly biconcave outline on the flank witha broadly rounded lateral ear between the twosinuses. This must be a macroconch,
although regrettably it was not illustrated.
To sum up, I suggest that H. buszii Wegneris highly possibly a junior synonym of H.
pseudogardeni (SchWter), although I shouldreserve the final conclusion until I could
examine the original specimens of Wegner.
The extent of variation in H. pseudogardeni should be studied on the material of
populations, but this is outside of my present
capacity. According to Muller and Wollemann (\ 906), the variation does not seemlarge. I give below a revised specific diagnosis of H. pseudogardeni mainly on the
ground of the observations described above.
Diagnosis. - Shell discoidal, consisting ofmuch compressed whorls of moderate expansion and considerable involution, with nearlyflat or only gently convex flanks, which converge to fastigiate and keeled venter. Umbilicus fairly narrow, surrounded by low but
vertical wall and angular edge.
Periodic constrictions typically weak, narrow and gently flexuous; shallowly biconcave on the main part of flanks and markedly
projected on the ventral part. A ventrolateral row of nodulose, prorsiradiate riblets or
tiny nodes occur at least in some period of
growth.
Suture finely and deeply incised, with tripartite lateral lobes and bifurcate saddles. L
subsymmetric, somewhat deeper than, or nearly as deep as E; U2 and auxiliaries descending gradually toward the umbilical seam.
Microconch small; macroconch very large,
sometimes three to five times as large as
microconch in diameter.

443

Part II. Dimorphism in Hsuericeras(by T. Matsumoto, S. Toshimitsu
and Y. Kawashita)
Foreword

Hauericeras angustum Yabe, 1904, which
was redefined later by Matsumoto and Obata(1955) occurs fairly commonly in the Upper
Cretaceous (Santonian and Campanianstages) of Japan and South Sakhalin. Our
observations in field and museum works tellthat some specimens of this species are fairly
large and some others small or medium sized.
Meanwhile, Kawashita obtained on September 25, 1973 a fine specimen of complete
preservation from the Haboro area of northwestern Hokkaido. Obata et al. (1978) studied the apertural features of this and other
Cretaceous ammonites, with reference to functional implications.
When Matsumoto looked at this specimen,
he thought at once that it must represent an
adult microconch of H. angustum and muchlarger ones must be macroconchs. At T.M.'s
suggestion, Toshimitsu has recently found afine example of an adult macroconch of thesame species in his large collection from theHaboro area. There are some more specimens which can be compared with these twos.
We describe below these examples of dimorphism in more detail.
The repositories of the specimens dealt
with in Part II are as follows, with abbreviated headings:
BM: British Museum (Natural History),
London
GK: Department of Geology, Kyushu
University, Fukuoka
MNHN: Museum Nationale d'Histoire
N aturelle, Paris
UMUT: University Museum, Universityof Tokyo, Tokyo
YKC: Yoshitaro Kawashita's Collection,
which will be eventually transferred to somemuseums as will be Y. Yokoi's Collection at
Kenbuchi, Hokkaido.

444

Tatsuro Matsumoto

Figure 2. Hauericeras angusfUl11 Yabe. GK. H8119 , ob tai ned by S.T. at loc. RH. 2532e, Haboro
area. Macroconch preserved comp lete ly up to the peristome. Lateral view (A) and cross-section (8)along the fracture Q-R. Arrow = position of the last septum. Scale bar = 20 ffiffi. Photos by M. Noda and
S.T.

898.

On Hauericeras

Macroconchs of H. angustum
Best example. -GK. H8119 (Figures 2-4)
is the best preserved. It was obtained by S.
T. from the Zone of Inoceramus (Platyceramus) japonicus at loco RH. 2532e in thesection along the Naka-no-futamata-gawa, atributary to the River Haboro, northwestern
Hokkaido (see Toshimitsu, 1988 for the location and stratigraphy).
This specimen is complete in showing the
body chamber up to the peristome. The
phragmocone ends with 0= 155 mm and thesucceeding body chamber is as long as 220° at
the base of the apertural margin and 24Y at
the apex of the rostrum. The entire shell
diameter measures 225 mm and 235 mm at therespective points mentioned above.
As the measurements in Table 2 shows, therate of whorl expansion is rather low, degreeof involution roughly 1/3, umbilicus of moderate width (roughly 1/3 of D), and the whorl
is compressed, with B/H = 0.5 in the late partof the phragmocone. The body chamber issecondarily compressed. These charactersand rather flat flanks converging to the keeled
venter (which is less sharply fastigiate on theinternal mould) conform with the diagnosis
already given by Matsumoto and Obata(1955, p. 139).
The peristome is distinctly sigmoidal on
Table 2.

445

the flank, passing to a markedly projectedventral rostrum. It shows a broad and moderately deep outer lateral sinus and a smaller
but distinct umbilical sinus, with an obtusely
convex, subrounded ear inbetween. This
sigmoidal curve of the peristome is more
pronounced than the gently flexuous growthlines or lirae on the main flank of the bodychamber. There is a very shallow and widezone of depression (8 to 10 mm in breadth) inparallel with and immediately behind agently flexuous, weakly raised lira which issituated about 15 to 25 mm apart from theperistome (see Figure 3). This zone may be
a kind of constriction which contracted the
body chamber at the base of the apertural
margin. As the body chamber of this specimen is secondarily compressed, the original
degree of contraction may have been reduced.
There is another, narrow and shallow, indistinct constriction on the body chamber about
180° back from the broader one mentioned
above. Aside from the above described features, the surface of the body chamber issmooth, without any sign of ventrolateralriblets or nodes.
The constrictions on the septate whorl are
infrequent and weak. The surface is smooth,
except for flexuous lines of demarcation
which may imply the occasional arrest of
growth (Figure 4).

Measurements of Hauericeras angustum (in mm).
D

U

H

B

B/H

H/h

lnv.

(M)

225.0 (I)

100.0 (044)69.0 (.31)

-

-

1.23

0.33

(LS)
(LS-1800)

155.0 (I)63.0 (AI)52.0 (.34)

26.5 (.17)

0.50

1.30

0.35

118.0 (I)45.5 (.39)

40.0 (.34)

20.0 (.17)

0.50

1.25

-

(M)

113.0 (1)46.3 (AI)38.2 (.34)

c. 17 (.15)

0045

1.34

0.36

1/

(LS+ 180°)

105.5 (I)4104 (.39)

35.0 (.33)

-

1.20

-

1/

0049

-

-

0.50

1.34

0.37

0.53

1.27

0.37

0043

1.31

-

Specimen (Position)
GK. H 8119
1/
1/

YKC. 480925

-

(LS)

c.75 (I)27.8 (.37)

26.8 (.36)(LS+ 180°)

93.0 (I)37.2 (040)32.0 (.34)

GK. H 3322

(E)

123.0 (I)48.0 (.39)

42.0 (.34)

c. 13 (.17)
c. 16 (.17)
22.3 (.18)

GK. H 8321

(LS+ 180°)

98.0 (l)36.0 (.37)

36.0 (.37)

1504 (.16)

UMUT. 1-274

M = base of the apertural margin; LS = last spetum; others as in Table I.
GK. H 3322 is measured on the internal mould. GK. H 8321 is distorted but measured as it is.

446

Tatsuro Matsumoto

Figure 3. Hauericeras angus/um Yabe. G K.
H8ll9 (same as in Figure 2) , showing the details of
the apertural margin , growth lines (thin broken lines)
and lines of demarcation (fine sol id lines). Sca lebar = 10 mm. T.M. de/in.

Other examples. - There is another macroconch specimen of H. angustUl11 whichshows the peristome. It was obtained byMototaka Hayashi from the Inoceramus(Platyceramus) japonicus bearing formation
at Onnebetsu-Hokusen , Shibetsu area ofnorthwestern Hokkaido. It is now kept inYokoi 's Collection with No. 725. Although
the spec imen is badly damaged, one of us (T.
M.) observed that it is roughly as large as GK.
H8ll9 , its body chamber as long as 230°, andthat its peristome shows, though incompletely, a broader, outer lateral sinus, an obtusely
convex ear and a smaller umbilical sinus; its
ventral rostrum was destroyed away.
Maeda obtained another example of amacroconch from northern Hokkaido. It
shows incompletely the apenural margin. It
is held in Kochi University.
There are more specimens which can be
regarded as macroconchs of H. angustum.
For example, GK. H5141 (Matsumoto andObata, 1955, pI. 24, fig. 6) and GK. H52l9(ditto , pI. 28 , fig. I), both from South Sakhalin , are 125 mm and 115 mm in diameter at

Figure 4. Hauericeras angus[um Yabe. A
part of the inner whor ls of GK. H8ll9 (same a s
Figure. 2), showing sutures at about 2.5 whor ls
adapically from the peristome and also occasionallin es of demarcation. Scale bar = 5 mm. Photo by

S.T.

the last septum and the diameter of their
entire shells may have been about 200 mm
and 170 mm respectively , although thepreserved body chambers are incomplete (andsecondarily crushed in GK. H5l41) , without
showing the apertural margin. Incidentally,in GK. H5141 the constrictions are fairly
frequent in the period from the last part of thephragmocone to the beginning of the bodychamber. Also in the late part of somemacroconchs, raised lirae or subcostae may
appear on the inner flank. They show gently
convex curve as a part of the flexuous growthline. Moreover lines of demarcation occasional ly appear, showing a moderate convexity on inner flank. They may occur in microconchs as well (Figure 5). The bodychamber does not seem to broaden particularly in macroconchs, although it is often secondarily compressed or crushed.

898.

On Hau ericeras

447

t:'
I

,

c

D

Figure 5. Hauericeras angus{ul11 Y abe. G K. H3534 fro m loc. U505, Ik a ndai , U ra kawa a rea (T. M.
Co l!.) , a j uve nil e show in g occasio na l lin es of demarca ti o n on the surface of shel!. Ri ght (A ) a nd left (8 )la tera l, bac k (C) a nd fr o nta l ( 0 ) views, x 2. Sca le ba r = 10 mm. Ph oros by M. No d a.

Microconchs of H. angllstllm

Best example.- The best preserved mlcroco nch exa mpl e o f H . angustum is the
spec ime n YK C. 480925 (Fi g ures 6 A , B). It
was indicated as KCI002 by Ob a ta et al.
(1 978 , fig . 4 ; pI. 3, figs. I a - d) . It waso bta in ed in 1973 by Y . K awas hita fr o m the
Ainu-zawa , a sm a ll tributa ry to th e R ive r
H a bo ro.
Thi s specime n is co mpl ete in show in g thee nt ire she ll up to the a pe rt ura I ma rg in. Th ehea d o f th e las t suture is at D = 75 mm a nd thelast two sutu res a re approx im a ted , suggestin g
th at thi s a mm o nite w as m ature. Th e bo d yc ha mber is 240' at the base o f th e a pertura lma rg in a nd 265' at the a pex o f the rostrum .
Meas ured dime nsio ns of thi s spec imen at
three pos it io ns a re sho wn in T a bl e 2.
The peri sto me o f thi s spec ime n is ma rk ed
by a fa irl y lo ng a nd na rro w, ve ntra l rostrum ,deep ve ntro la tera l sinu s, to ngue lik e la ppeta nd fa irl y deep , se mi-sinu s towa rd th e umbilica l ed ge. The la ppet a ri ses fro m its o btuse ly
co nvex basa l part a t a po int so mew ha t d o rsad
fro m th e middle o f flank a nd is e lo nga ted
ho ri zo nta ll y (in stea d o f spira ll y), w ith its
a pex a pproachin g to the middl e of fl a nk . It

has de nse a nd fin e li rae, w hich show fo rwa rd
co nvex , sho rt c urves, a nd e nd s a t a subro unded a pex. On th e left side o f the she ll th ere isa trace of inj ury in th e basa l p a rt o f thela ppet, which ho wever, went o n to gro w
no rm a ll y.
In thi s spec ime n the she ll y m ate ria l ispreserved o n the las t ha lf of th e bo d y ch a mbera nd a very thin inn e r she ll layer m ay rem a ino n so me pa rt of t he poste ri o r h a lf. Th e fin elirae a nd stri ae in th e b asa l zo ne o f the a pertura l ma rgin are m o derate ly sigmo id a l, showin g a c urva ture simil a r to th a t o f the peristo me of a m acro co nch. The re is a lo w
e levati o n in pa ra llel w ith the o btu se ly co nvex
li rae o n th e b asa l p a rt o f the la ppet. It is
ra ised o nl y on the inn e r fl a nk , fa din g aw ay
o ut ward .
In a n ea rl y grow th stage (D < 10 mm) , irregul a r e leva ti o ns w ith a co nvex c urve a re di scernibl e o n the inne r flank (see F ig ure 6c ) as
in those of the ho lo ty pe (UMUT. MM 7573 ).
In cid e nta ll y, th e sca rs o f mu sc le a ttachm ent
a re we ll show n o n th e inn er fl a nk s in the
ad a pi ca l (i .e. posteri o r) p art o f the bo d ych a mber.
The phragm oco ne of thi s spec ime n isa lm ost devo id of th e extern a l she ll a nd

448

Tatsuro Matsumoto

Figure 6. Hauericeras anguslUln Yabe. YKC. 480925 from the Ainu-zawa, Haboro area (Y.K.
Col!.), an adult microconch preserved completely upto the peri sto me. Right (A) and left (C) lateral ,frontal (8) and back (D) views, X I. Arrow = head of the last suture. Scale bar = 10 mm. Photos by M.
Noda. (to be continued to page 449)

sutures are finely exposed on the internalmould. L is nearly as deep as E and subsymmetrically tripartite. Saddle E j L is asymmetrically bifurcate with a smaller foliole on
E side, and a larger branch on L side is again
bifurcate. Saddle L j U2 is bifid. U2 nearly
erect, about a half of L in size, and asymmetrically tripa rtite. Auxiliaries are descending abruptly toward the umbilical seam.
This pattern of suture is essentially simil ar tothat of a macroconch (see Figures 6, 4).
Other examples. - UMUT. MM7575 = GT.
1-274, from Urakawa , is one of the specimens
which were identified with H. gardeni(Baily) by Yabe (1904, p. 32). It was revised

to H. angustUl11 by Matsumoto and Obata(1955 , p. 137 , pI. 29, fig. I). It is nearly 100
mm at the preserved end. Its body chamberis preserved for about 220 and the sutures in
the last part of its phragmocone are approximated. Therefore, we can regard it as anadult microconch , whose last portion was
regrettably destroyed away. Its diameter in a
restored outlin e (on the assumption that the
body ch a mber was 240 at the base of theapertural margin a nd 26Y at the apex of therostrum) can be inferred to be somewhere
between 110 mm and 120 mm . This is nearly
the sa me size as YKC. 480925 , an undoubted
microconch described above .
0

0

898.

On Hauericeras

GK. H3322 , from the Santonian of Urakawa, measured and illustrated by Matsumoto and Obata (1955, p. 139, pI. 28 , figs.
l a, b) is probably an incomplete microconch ,for its diameter is 123 mm at the preservedend (that is 230' from the beginning of the
body chamber) a nd about 80 mm at the last
septum. It is slightly (8% or so ) larger than
YKC. 480925 , although its apertural margin
is unpreserved. The growth lines or lirae on
the surface of shell are gently fle xuou s on theflank and markedly projected on the ve ntral
part.
GK. H8321 (Figures 7A - C) is a possible
but questionable example of a microconch.

449

It was acquired on July 19, 1988 by Noda ,Takahashi and T. M. in a drifted nodule in
the Hiromine-zawa at loc. Ik. 8049 p, 30 m
up stream from the confluence with the
Kikume-zawa in the Ikushumbets valley. Itsderivation is uncertain , for some structuralcomplexity in the geology of this local area.
Although a bed of shale with Inoceramus(Platyceranus) japonicus is exposed at loc.
Ik . 8101 about 50 m east from Ik. 8049, its
extension in the Hiromine-zawa is sti ll
obscure.
Anyhow , it is secondarily di storted to an
ell iptical out line of 106 mm X 90 mm , but its
bod y chamber, which occupies two third s

450

Talsuro Malsumoto

Figure 7. Hauericeras anguslUm Yabe. G K. H 832 1 from loco Ik8049p, Kikume-zawa , Ikushumbets
area , (M. Noda, T. T aka hash i and T.M . Co il.) Probably a microconch, wi th out lappets (secondarily destroyed or not yet grown), Ri ght (A) and left (B) latera l and back (C) views, X 1. Arrow = approx im a teposition of the last suture. Scale bar = 10 mm. Pho tos by M. Noda

898.

On Hauericeras(i.e. 240') of the outer whorl, is preserved up
to the apertural margin. It is slightly smaller
than YKC 480925 and may be roughly 20%
smaller than GK. H3322 (see Table 2).
The peristome of this ammonite is considerably sigmoidal on the flank and markedly
projected on the venter. Its flexuous curvature is quite similar to that of the basal zone
on the apertural margin of YKC 480925.
For some reasons, it is devoid of tongue-likelappets on either side. Therefore, the curvature of its peristome is analogous to that of amacroconch, if the size difference is ignored.
As to the above features, three possible
cases can be considered, viz. (I) the lappets
existed originally but were destroyed away;(2) the ammonite died before the formationof long lappets; (3) this is a fossil of animmature or middle-aged female ammonite(macroconch) who was in a temporary repose
during growth.
We have mentioned that the basal part ofthe lappet was injured on the left side of
YKC 480925 (Figure 6C) and then thelappet went on to grow completely. This
tells us that there was a time of repose after
the basal part of the apertural margin wasformed and then the very peristome with longlappets may have been completed at the last
growth stage. This seems to be favourable
for the second case, but the third case (without lappets at all) cannot be ruled out. As
the sutures are only partly observable in thisspecimen, it is difficult to decide whether thisspecimen is mature or immature from theapproximation of the last sutures. There is ablunt elevation in the basal part of the apertural margin in this specimen as in YKC
480925, but similar riblets or subcostae occur
frequently in the inner flank of the bodychamber and the preceding last part of thephragmocone of macroconchs. The mode ofappearance of a single elevation favours theinterpretation that this specimen is a mi-croconch.
In a microconch (TTC 53086) of Mesopuzosia pacifica Matsumoto (Matsumoto et451

al. in Matsumoto, 1988, fig. 8C), the lappeton its left side was cut off from the base of theapertural margin and going to be displaced toelsewhere, whereas the one on the right side
was safe (ditto, fig. 8A). This fact suggeststhat the first case may be probable.
Anyhow, we are inclined to regard GK.
H8321 as an example of a microconch. We
have learned from the above observations thatlappets may not be always preserved even in
microconchs. Therefore, the distinct difference in size between the adult shells and theidentity of the characters between the young
to middle-aged shells are important to recognize the dimorphism in a given species.
Dimorphism in other speciesof Hauericeras
Dimorphism in H. angustum has been
made clear on the basis of several specimens
as described above. Then, how are otherspecies of Hauericeras ?
H. pseudogardeni (Schlliter).-In Part I
this species has been redefined. It has beensuggested already that the lectotype and certain other large specimens of this species may
be macroconchs, whereas the small form
called H. mengedensis (SchlUter) may be a
microconch of H. pseudogardeni.
H. gardeni (Bailey, 1855).- This is a wellknown species, which is allied to H. angustum but distinguished from the latter in its
frequent and well marked, concave constrictions and somewhat broader whorl (i.e. larger
BjH) (see Matsumoto and Obata, 1955, p.
140-144).
BM. C18518, from South Africa, is probably a microconch, although the apertural
margin is not preserved. Its diameter is 135
mm at the preserved end and its body chamber occupies 230' (ditto, fig. 10). It is slightly larger than GK. H3322, a microconch
example of H. angustum.
On the other hand, there are at least two
illustrated specimens which probably represent macroconchs of H. gardeni. They are452

Tatsuro Matsumoto

MNHN. 2599 and MNHN. 2664, from theLower Campanian of Madagascar and measured as D = 183 mm and 195 mm respectively
at the preserved end (Collignon, 1961, pis. 28,
29). If the peristome is preserved, they must
be somewhat larger, being nearly similar insize to G K. H8119, a macroconch example of
H. angustum.
To sum up, the size difference between thedimorphic pair of H. gardeni is approximately comparable with that of H. angustum.
The specimens of H. gardeni which show theapertura I margi n have yet to be searched for.

Other species. - In addition to the three
species described above, there are more
species of H a uericeras. For instance, H.
sulcatum (Kner, 1850) (see also Kennedy andSummesberger, 1987, p. 27, pI. 1, figs. 1-7; pI.
13, fig. 2), H. Jayoli de Grossouvre (1894, p.
220, pI. 27, fig. 3) (see Kennedy and Summesberger, 1984, p. 157, pI. I, figs. 8, 12; pI. 2,
figs. 4, 13-15) and H. buszii Wegner (1905, p.
208, pI. 8, figs. I a, b) are well known andoften cited, but we have had no opportunity
to examine the actual specimens of them.
According to Wegner, a large specimen of H.
buszii seems to have a flexuous peristome witha broadly rounded ear, It may be a macroconch. Moreover, H. buszii may be a synonymof H. pseudogardeni (see Part I).
H. rembda (Forbes, 1846), from the Maastrichtian stage of southern India and Japan,
are represented by very small specimens.
They may be microconchs but larger, possible
macroconchs, as well as its complete specimens with peristomes, have yet to be searchedfor. There is a fairly large specimen (with D
more than 200 mm) of Hauericeras which was
obtained from the upper (but not uppermost)part of the Maastrichtian formation exposed
at Senposhi on the coast of Akkeshi Bay,eastern Hokkaido, by Tsunemasa Saito, whoshowed it to T.M. It is so badly crushed that
it is hardly identified. It is now held in
Department of Earth Sciences, Yamagata
University. Noteworthy is the fact that evenin the late Maastrichtian species of Hauericeras a macroconch was fairly large.
Part III.

Affinities of Hauericeras(by T. Matsumoto)The genus Hauericeras has so distinctive
characters that it is not affiliated to the Dcsmoceratinae nor to the Puzosiinae. Hence,the subfamily Hauericeratinae was proposedby Matsumoto (1938) and has been maintained (e.g., Wright, 1981, p. 169).
The phylogenetic origin of Hauericeras is
uncertain. Wright (1955, p. 567) suggested it
in a compressed species of Tragodesmoceroides Matsumoto, 1942, a Turonian memberof the Desmoceratinae. Matsumoto andObata (1955, p. 134) noted a close affinity ofHauericeras with Tragodesmoceras Spath,
1922 of the Muniericeratidae. Wright (1957,
p. L371) stated that the origin of the Hauericeratinae is doubtful but probably in the
Desmoceratinae close to the point of origin of
the Muniericeratidae. Unlike Hauericeras,
the latter is an ornate group.
Although Wright (1955, p. 567) once postulated a much compressed, unornamented
species of Puzosia as another possible origin,
he complained of the absence of such species
in the Upper Turonian and Coniacian in theavailable material at that date.
The idea of Puzosia origin should now bereconsidered. Puzosia manasoaensis Collignon, 1961 (p.34, pI. 5, fig. 2), from theConiacian of Madagascar, is much compressed, very feebly ornamented and medium
sized. A form which was found rarely fromthe Coniacian of Hokkaido and describedunder P. cf. manasoaenis by Matsumoto andKera (in Matsumoto, 1988, p.43, fig. 7) isflat-sided, much compressed, nearly smoothand very large. The former may be a microconch and the latter a macroconch. Anyhow, these ammonites meet the requirementof Wright mentioned above.
Hauericeras antiquum Collignon (1961, p.
75, fig. 12), from the Coniacian of Madagas-

898.

On Hauericerascar, is very interesting in that it has numerous,
projected but short ribs on the ventral part.
This species and Puzosia cf. manasoaensis
cited above are so far represented respectively
by a single, incompletely preserved specimen,
but could be regarded as rare but valuable
forms which may link a typical species ofHauericeras with that of Puzosia. The riblets or small nodes on the ventrolateral shoulders of H. pseudogardeni and probably synonymous H. buszii could be interpreted as
ornaments which survived, with somemodification, from the short ribs of such a
species as H. antiquum.
Puzosia kuratai Tokunaga et Shimizu,
1926 (p. 196, pI. 22, fig. 6, pI. 23, figs. 4, 5, pI.
24), from the Coniacian of the Futaba area
(about 200 km northeast of Tokyo), could be
another linking species, but there is somedifficulty about it (Matsumoto et al., 1989).
Still more interesting is the recent find of akeeled species of Puzosia from the midTuronian of northern Mexico. That is
Puzosia (P.) serratocarinata Kennedy et Cobban (1988, p. 595, fig. 2; fig. 4: 1-3), whoseshell-form in gross view is similar to that ofHauericeras. The riblets on the outer part of
the whorl of this species are similar to thoseof H. antiquum mentioned above. The keelof Hauericeras was described as septate bysome authors, but actually it is solid (seeMatsumoto and Obata, 1955, p. 144; also see
Figures I, 2B of this paper). Therefore, P.
serratocarinata could possibly be transferred
to Hauericeras. As it exhibits an obtusely
fastigiate, keeled venter and sutures of thetypical Puzosia pattern, I would agree at least
for the time-being with Kennedy and Cobban
in their assignment of it to Puzosia. Anyhow, it does have an incipient keel, showing
a tendency to give rise such species as H.
antiquum.
It should be noted that a young shell ofHauericeras has no keel (see Matsumoto andObata, 1955, fig. 5), being quite similar to thator Puzosia or Mesopuzosia (see Matsumoto,
1954, fig. 2).

453

The evolute species of Hauericeras, such as
H. gardeni and H. angustum, have a distinctly retracted umbilical lobe, as in Puzosia.
In the more involute species, e.g. H.
pseudogardeni, the auxiliaries are descending
gradually. This feature is, however, analogous to that in the species of Bhimaites, aninvolute genus of the Puzosiinae. In the
suture of Hauericeras, regardless of the degreeof the retracted feature, L is not so large nor
so asymmetric as in that of Puzosia andBhimaites. This difference could be formedby some modification in the ontogenetic
development.
In the discussion of the affinities, I shouldtake dimorphism into consideration. The
diameter of macroconchs in restored outline
is 430 mm or so in the studied specimens of P.
elegans Matsumoto, 1988 (much compressed
and weakly ornamented species from theUpper Cenomanian of Japan) and P. cf.
manasoaensis (mentioned above). That of
the lectotype (probably macroconch) of H.
pseudogardeni in restored outline is 420 mm,
as described in Part I. Thus, as to the absolute size of macroconchs, the type species ofHauericeras has the same order of magnitude
as certain species of Puzosia.
I presumed in Part I that the lectotype ofAmmonites mengedensis may be a microconch example of H. pseudogardeni. Its diameter is only 75 mm to 80 mm in a restored
outline. This difference in size is approximately comparable with that between macroand micro-conch examples of Puzosia subcorbarica Matsumoto, which show 400 mm versus 90 mm (see Matsumoto, 1988, fig. I).
In the examined species of the Desmoceratinae, I have not seen any example of such alarge size nor such a great difference in size
between dimorphs, if any, as in some speciesof the Puzosiinae and Hauericeras. There is,however, little knowledge as to the dimorphism in the members of the Desmoceratinae.
Therefore, I attempt, together with somefriends of mine, to collect the material which
may be useful for this problem.

454

Tatsuro Matsumotot
Figure 8. Neopuzosia ishikawai (limbo). GK. H8l28A from loco RH2511h2 , Naka-no-futamatagawa, Haboro area (S. Toshimitsu Coll.). An adult macroconch preserved up to the apertural margin.
Back (A) , left (8) and right (C) la teral views, X I. Arrow = position o f the last suture. Scale bar = 10mm . Photos by M. Noda. (to be continued to page 45 5)

As to the apertural margin of the bodychamber, the markedly rostrate and lappeted
peristome is common between the microconchs of Hauericeras and Puzosia or Mesopuzosia or even Neopuzosia. The peri stomeof a macroconch of Hauericeras , as observedin H. angustum , has a long ventral rostrum
and is distinctly flexuous and fairly deeply
biconcave on sides, with obtusely convex ear
between a wide and moderately deep outersinus and a small but fairly deep , inner (probably ocular) sinus. This is somewhat similar
to but not identical with the distinctly
flexuous constrictions on the body chamberof Desmoceras (Pseudouh ligella) japonicum
Yabe, 1904. The peristome of the lattershows a more pronounced flexuosity , having
moderately to rather narrowly rounded ears
and a long projected rostrum with a moderately rounded apex.

898.

On Hauericeras455t

In my preliminary obsevations, there aresome differences between several species of D.
(Pseudouhligella) as to the curvature of theperistome or that of constrictions. Therefore , it is too hasty to give general remarks on
the difference of apertural margin between
Hauericeras and Desmoceras or any othergenera of Desmoceratinae.
The peristomes of the investigated macroconchs of the Puzosiinae are simply con-cave to gently flexuous on the flank andmoderately to strongly projected on theventer with a flare or constriction behind it(see Stoliczka, 1865, pI. 68 for Puzosia ; Matsumoto , 1988, fig . 40, for Jimboiceras ; Matsumoto , 1989, pis. 1,2, text-fig. I for Pachydesmoceras). This is considerably
different from the peristome of Hauericeras
macroconchs descri bed above .
Macroconchs of Neopuzosia and Kit-

456

Tatsuro Matsumoto

chinites, are smaller than those of undoubted
genera of the Puzosiinae and their peristome
is only gently flexuous on the flank, with very
shallow ventrolateral sinuses, and a rather
short rostrum on the venter (see Matsumoto,1988, figs. 31 A, 32A, 35; also this paper,
Figure 8). Despite the simi I arity in the apertural margi'n of microconchs, Hauericeras is
distinct from Neopuzosia and Kitchinites in
the character of the peristome of macroconchs.
It is interesting to see that in some speciesof K itchinites, e.g. K. spathi Henderson et
MacN amara (1985, p. 57, pI. 4, figs. 5-6, 9-10,
14-15), whorls of early growth-stage aresmooth and short riblets appear on the latewhorl, showing an apparent similarity to
microconchs of Hauericeras pseudogardeni.
As Kitchinites (s.s.) appeared later in age than
Hauericeras, the former cannot be an ancestor of the latter. Thus, the similarity is ahomeomorphy between different but somewhat allied phylogenetic groups. There isanother example of the reduction in ornaments in the Puzosiinae. That is the genus
Epipuzosia Matsumoto, 1988 of CenomanianTuronian age, but it maintained the thickwhorls of probably ancestral Pachydesmoceras.
Taking all the aspects of the above observations into consideration, I am rather inclined
to ascribe the phylogenetic origin of Hauericeras in a much compressed and weakly
ribbed subgroup of Puzosia. Should thisview be warranted, my recent proposal (Matsumoto, 1988, p. 6) to combine the subfamilies Puzosiinae (in my sense, loco cit.)with Hauericeratinae in to the family
Puzosiidae would be approved.
Many, if not all, genera and species of the
Puzosiidae have probably sexual dimorphs ofgreat difference in size and their adult female
shells (i.e. macroconchs) are large or gigantic
and often show modified shell-forms and/or
peculiar ornaments of their own. These features are significant not only morphologically
but also anatomically and physiologically. I

would eval uate them to be sufficient for therank of family.
The above is my tentative proposal. There
are yet some incomplete or questional points
to be investigated further, as I have discussed
above. For this reason, someone may favour
a conservative attitude to keep the subfamilies
Desmoceratinae, Puzosiinae, Hauericeratinae,
Beudanticeratinae and Silesitoidinae to begrouped into the family Desmoceratidae,
without giving a special importance to thepeculiar features which I stressed.
Incidentally, the subgenus Hauericeras(Gardeniceras) Matsumoto et Obata, 1955,
which was suppressed by some subsequentauthors, can be redefined as a subgroup of
Hauericeras in which ventral or ventrolateralriblets or nodes disappeared completely,
whereas Hauericeras (Hauericeras) is the
subgroup in which ventral or ventrolateral,
prorsiradiate riblets or nodes remain at leastin certain stages of growth.
As Matsumoto and Obata (1955, p.139)
have mentioned, in some specimens of H.
(G.) angus tum , faint, gently convex andradial elevations may appear irregularly on
the inner half of flank. In the holotype,which is immature, they are well discernible
in an early growth-stage, but in some otherspecimens (e.g., GK. H5213 and GK. H5141)
they occur on the outer whorl.
The available records of occurrences tellthat H. (Hauericeras) ranges from theConiacian to Santonian and that H. (Gardeniceras) ranges from the upper part of theSantonian to fairly upper part of the Maastrichtian. In my view, the two subgenera
may reflect stages of an evolutionary change.
Acknowledgements

I wish to record my debt of gratitude toProfessor Dr. KJ. MUller of the Rhein Friedrich-Wilhems U niversitat, Bonn, and Dr.
Herst Remie, Curator of the PalaeontologicalMuseum of the same university, for every
facility which they afforded for my study of898.

On Hauericeras

the type specimens described by the lateProfessor Clement Schlliter (1871-1872;
1876) during my stay there in May 1965.
Thanks are extended to Professor Itaru
Hayami and Dr. Takashi Okamoto for their
help to my restudy of the types held in the
UMUT, Tokyo.
Dr. Seiichi Toshimitsu and Mr. Yoshitaro
Kawashita kindly joined me in the study ofdimorphism with supply of fine specimens of
their collections. Mr. Katsujo Y okoi, Dr.
Haruyoshi Maeda and again Dr. S. Toshimitsu generously showed me the relevant
specimens of their collections with fruitful
discussions. Professor Tsunemasa Saito and
Dr. Hirotsugu Nishi kindly showed me a
specimen from eastern Hokkaido with necessary information. Dr. Masayuki Noda
friendly took photographs of selected specimens. Dr. Noda also helped me, together
with Mr. Takemi Takahashi (Mikasa), in thefield work (1988) of the Ikushumbets area.
Miss Kazuko Hara faithfully assisted me inpreparing the typescript.

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Kijn. Preuss. Geol. Landesamt, N. F., vol. 47, 30
p., II pIs.
Obata, 1., Futakami, M., Kawashita, Y. and Takahashi, T., 1978: Apertural features in some
Cretaceous ammonites from Hokkaido. Bull.
Natf/. Sci. Mus., Ser, C (Geol. & Paleont.), vol.
4, no. 3, p. 139-155, pIs. 1- 3.
SchlUter, c., 1871-1872: Cephalopoden der oberen
deutschen Kreide. Palaeontographica, vol. 21,
p. 1-24, pIs. 1-8 (1871); p. 25-120, pIs. 9-35
( 1872).
- - , 1876: Ditto. Ibid., vol. 24, p. 121-264, pIs.
36-55.
- - , 1899: Podocrates im Senon von Braunschweig
und Verbreitung und Benennung der Gattung.
Zeitsch. Deutsch. Geol. Ges., vol. 51, p. 409-430.
Spath, L.F., 1922: On the Senonian ammonite fauna

Tatsuro Matsumoto458

of Pondoland. Trans. Roy. Soc. S. Afr., vol.
10, p. 113-147, pIs. 5-9.
Stoliczka, F., 1865: The fossil Cephalopoda of theCretaceous rocks of southern India. Mem.
Geol. Surv. India, Palaeont. Indica, p. 41-216,
pIs. 26-94.
Tokunaga, S. and Shimizu, S., 1926: The Cretaceous
formations of Futaba in Iwaki and its fossils.
Jour. Fac. Sci. Imp. Univ. Tokyo, Sec. 2, vol. I,
pt. 6, p. 181-212, pIs. 21-27.
Toshimitsu, S., 1-988: Biostratigraphy of the Upper
Cretaceous Santonian stage in northwestern
Hokkaido. Mem. Fac. Sci. Kyushu Univ., Ser.
D, Geol., vol. 26, no. 2, p. 125-192, pIs. 23-29.
Wegner, T., 1905: Die Granulatenkreide des westlichen Miinsterlandes. Zeitsch. Deutsch. Geol.

Ges., vol. 57, p. 112-232, pIs. 7-10.
Wright, C.W., 1955: Notes on Cretaceous ammonites. - 11. The phylogeny of the Desmoceratacea_ and the Hoplitaceae. Ann. Mag. Nat. Hist.,
Ser. 12, vol. 8, p.561-575.
- - , 1957: In, Moore, R.C. ed., Treatise on invertebrate paleontology, Part L, Mollusca, Cephalopoda, Ammonoidea, p. Ll-L400, Geol. Soc.
America and Univ. Kansas Press.
- - , 1981: Cretaceous Ammonoidea. In, House,
M.R. and Senior, J.R. eds., The Ammonoidea.
System. Assoc. Spec. Vol., no. 18, p. 157-174.
Yabe, H., 1904: Cretaceous cephalopoda from the
Hokkaido. Part II. Jour. Coli. Sci., Imp.
Univ. Tokyo, vol. 20, art. 2, p. 1-45, pIs. 1-6.

Ainu-zawa ~~IR, Akkeshi )!j/¥, Chiyoda T-K:B3, Fukuoka 1'i'liIli'iJ, Futaba :gz=lt,
Haboro ;:pjm, Hiromine-zawa J1;:~IR, Hokkaido itwi!!, Ikandai fr~ir, Ikushumbets (Ikushunbetsu) mwlJlJ, Kikume-zawa 1rofi'ff1R, Kochi ~9;D, Mikasa '::='32:, Nakano-futamata-gawa t:p Il) =!Ili: JII, Onnebetsu-Hokusen IJlli tH lJlJ it~, Senposhi {llJ j\jJl:.
Shibetsu ±lJlJ, Tomatsu ~t0, Urakawa OOfoJ.
B:!!E$c 7 /' -"= T -1 d~ Hauericeras fC -:>t '-C : *~lit!t31'-lmJt£~1l) 1:: {ffl B :!!E*fcj£ L.J1;:
0
L. ii' L.f.Lfi(X1l) 3 ,~iI'*JW~-c'tr> 7.J .:: Clc3K#t ,t-:o .:: nvCX-;JT 7.J liIf~*a*:a:-~GTo (I) t~:t:f! Ammonites pseudogardeni 1l),ll.lb~iI':;r:IjJ.lIii-c'tr>"'? t-:o 4-@]1ft~:t::a:­:ttrlEL.-C:p}IE~L.t-:o 7i-1J\ij{fflfcm.ltt! (lliffCtH~It9) iI'tr>7.Jll)iI'*f!1l) I !ff1!t-c'tr>7.J o (II)=mltl:Il)::ff::efil'rp~~-c'tr>"'?t-:o **Bj£ H. angustum fc-:>t'-C~I:J~Il)*::ff:~n-Ct'7.J M~'m ~ll)ff17U:a:-~L., t~:t:f!~ H. gardeni vCin,-c t=mlll)tr>7.J':: c :a:-'mt,t-: o (III) *~Il) *jjlt1::Il){ftii':{tvtil'*JW~-c' tr>"'? t-:o *~fC:J:ovt 7.J =ml M'm ~Il)* ~ ~ Il)l:t c M ~ll)~xt{ilHi Puzosia ll)-tnfUil'!~~T 7.J ii', Desmoceras Il)~il" (liIf~t:p) c li~tJ:: 7.J o ::1.=:. '7 :/ 7 /' vC qo. -Iv li4W< t, iI,~:If} ii' Hauericeras fC {.);J, -C ~ t, ft1R:If} -c'.Itt! Il) ¥e:£ Il) fl!!< t,Puzosia Il)f!, ftP.:/Jqo.-Ivil'tr>lJm.ltt!iI'-tIl)f,lij1J\IHctr>7.J Hauericeras ll)f!iI'j£T7.Jo ~ GfC
f,ffl-c' Ii tr> 7.J iI'T -"- - p .=:. 7 /' fcm.ltt! iI'7i-fi'ff{fflt'= vt vC tr> IJ~t191l) qo. -Iv:a:- t -:>f!
(Puzosia serratocarinata) iI'J&JlI¥!i'5 ~ n -C t, 7.J 0 i t-:Mi*¥e~ :a:-t-: c' 7.J c Hauericeras Il)
f9J~li qo. -Iv:a:-J:: ~ -t 1l):If}1!tli Puzosia 1l)f9J~ Cj!i~{.);J,T 7.J 0 .:: n G Il) lm*~iI' G, Hauericeras Il):fJJ Mil) f! Ii Puzosia Il) t:p -C' ~:If} ii' ~ t ' f t1R;jj(: -c' .Itt! Il) ¥e:£ ii, :;r: -j- 5t tJ:: {ffl ~ (su bgroup) ll)f!iI'GEI3*L.t-:c7,..tJ::~n7.Jo m.ltt!~'J'~lt9li:!!E~ H. (Hauericeras) -C'fi!!t::ff:
L. -C t, 7.J ii', :!!E~ H. (Gardeniceras) -C'fi~ <m~ L. t-:o i t-::!!Etl- Puzosiinae c Hauericeratinae c:a:-{:lf-1t-C, tl-Puzosiidae cT7.Jll)iI'H'oto*:£&~(II lit0*:£&~ • flj:J't~- . JIITEI3*&~)o<9;0 G n -C t, 7.J:m

Trans. Proc. Palaeont. Soc. Japan, N.S., No. 158, pp.459-484, II Figs., June 30, 1990

899.

LATE MIDDLE MIOCENE FORAMINIFERAFROM THE MATSUE FORMATION,SHIMANE PREFECTURE*
RITSUO NOMURA
Department of Earth Sciences, Faculty of Education,
Shimane University, Matsue 690

Abstract. Late Middle Miocene benthic foraminifera from the Matsue Formation innorthern Shimane Prefecture are described, based on one boring well (depth 300 m).
Foraminiferal assemblages consist of 38 taxa, which include Ammonia cf. beccarii, Elphidium izumoense, n. sp., Elphidium ma(suense, n. sp., Buliminella elegantissima, Buccellacf. kuroma(sllnaiensis, Elphidiella praesomaensis, n. sp., Elphidium perforatum, n. sp.,
Pselldononion japonicllm and Trichohyailis sp.
A Q-mode principal component analysis reveals that the lower horizon is represented by
the E. perforatum, E. praesomaensis, and E. ma(sllense end-member assemblages and theupper stratigraphic horizon by A. cf. beccarii. These end member assemblages indicate that
the Matsue Formation was not only deposited in a shallow-warm water environment but also
influenced by a cold water. Generally, the assemblages of the Matsue Formation are closely
correlated with the present-day shallow-water assemblages of northern Japan. Based on the
results of principal component comparison, sediments of the lower horizon of the Matsue
Formation were deposited in an outer bay environment along with cold water elements.
The upper Matsue Formation is suggested to have been deposited in an inner bay environment of about 3 m water depth similar to Matsushima Bay, Northeast Honshu, Japan.
These results reveal that cold water elements extended to shallow area of San'in
sedimentary basin on the southern Japan Sea borderland at the late Middle Miocene age.
Key words.
Prefecture.

Benthic foraminifera, late Middle Miocene, Matsue Formation, Shimane

considered the Matsue Formation to be
Pliocene in age. His work was, however,based on a limited number of samples andthere are no subsequent micropaleontologicalinvestigations.
Molluscan fossils from the Matsue Formation have been studied by Otuka (1938) and
Nomura and Hatai (1939), and more recently
by Takayasu (1980). Molluscan assemblages
recorded by these investigators are considered
to be of Middle to Late Miocene, based on
the recent progress in biostratigraphy ofJapan (Tsuchi et al., 1981). However, amore precise age determination is hindered by
the non-occurrence of age-index microfossils

Introduction

The foraminiferal fauna of the Tertiary
deposits in Matsue City, Shimane Prefecture,
has been recognized by Tai (1959, 1973) as theuppermost biostratigraphic unit in western
Honshu, Japan. This biostratigraphic unit
named Ammonia cf. beccarii Zone is only
represented by the Matsue Formation in the
Shinjiko-Nakanoumi Lowland. At the proposal of this zone, Tai (1959) recognized theupper Rotalia-Bulimina faunule and thelower Nonion-Elphidium-Rotalia faunule, and"Received July 3, 1989; revised manuscript accepted
May 15, 1990
459

Ritsuo Nomura

460

from the formation. On the other hand,
Kano and Nakano (1985) dated the basaltic
andesite and assigned this formation to an ageof late Middle Miocene (11.5 ± 0.6 and 11.9 ±0.6 Ma).
This work is intended to provide fundamental data for the study of late Middle
Miocene shallow-water benthic foraminiferaof the San'in region and to present a quantitative analysis for the paleoenvironmental interpretation of the Matsue Formation.

Remarks on the lithostratigraphy of
the Matsue Formation
The Miocene sequences in the San'in
region are most typically exposed in thenorthern part of Shimane Prefecture, where
the Matsue Formation has the dimensions ofabout 12 km in E-W direction and 7 km in
N-S direction. The Matsue Formation
unconformably overlies the Furue Formationin the northern part of the Shimane Peninsula
and the Fujina Formation in southern hills.
About one-third of the distributional area ofthe Matsue Formation is overlain by theUpper Miocene Wakurayama Andesite (6.5
Ma; Kano and Nakano, 1985). The stratigraphic succession recognized in the Shimane
Peninsula is as follows:
Upper Miocene··.Wakurayama Andesite
Matsue Formation...... unconformity······
Furue Formation
Middle Miocene
Fijina Formation
Aishiro Formation
Josoji Formation
Lower Miocene .... Koura Formation
The Matsue Formation consists of coarseto fine-grained sandstone, intercalated basalt
and mudstone in various horizons. Tai(1952, 1955, 1959) recognized three membersin the Matsue Formation, noting the basaltic
tuff layers in the middle horizons. They are
the Teratsu Sandstone Member, Kawatsu Tuff

Member, and Kuroda Sandstone Member inascending order. Miyazima et al. (1972)
recognized six basaltic layers and two tufT
layers intercalated in sandstone, and showed
their stratigraphic relationship in a profile
section. According to them, the Matsue
Formation attains a maximum thickness over
400 m at Yada, west of Matsue City.

Core lithology
Samples analyzed in this paper are from awell drilled for investigation of the water
resources in northern area of Matsue City.
The well was drilled in 1983 by the Nishinippon Kensetsu Consultant Co., at Asakumi-cho of the City (Lat. 3Y28.0'N; Long.
133°6.9'E). It was cored to a depth of 300 m
from the surface which is 50 m above sea level(Figure I). Referred to the report of M iyazima et al. (1972), a 300 m of the well cores
would include almost all horizons of the
Matsue Formation. The cores consist of awide variety of clastic sediments, devoiding
the basaltic tuff layers exposed in the environs.
Based on the sedimentary units consistingof bluish coarse- to medium-grained sandstone and mudstone, two horizons are recognized from bottom to top (Figure 2). The
lower horizon (110.4-300 m depth) consists
mostly of medium-grained sandstone, whereas
the upper horizon (10-110.4 m depth) is characterized by frequent intercalation of mudstone layers and thinner sandstone layers. In
addition, conglomerate layers containing
granite, andesite and basalt are present at
14.8-14.9, 56.0-56.4, 201.5-201.6 m deep,
respectively. Lignite layers ranging from 3
cm to 90 cm thick are also present in thedepths of 27.5, 39.6, 70.5, 105.5, 111.0, 120.1,
198.5 and 211.5 m from the surface.
These sedimentary facies show that theenvironment of the basin changed upward, in
correspondence with the upheaval of the
Miocene basin during the depositional stageof the Matsue Formation (Nomura, 1986a).

899.
133 E

Miocene foraminifera from Matsue Formation

461

134 E

132 E

N

131 E

-$

35 N

LAKE

MATSUEolKm.....- - - - - 1 1

friif~ ~m
A

B

C

•o

Figure 1. Geologic map near Matsue City, Shimane Prefecture and location of boring core. A,
Sandstone and mudstone of the Matsue Formation; B, Basalt of the Matsue Formation; C, Wakurayama
Andesite; D, Drilled site.

Various sedimentary structures such as
laminations and sandpipes are usually developed in sandstone, and concretions consisting
mainly of Ostrea are included in the sandstone and mudstone.

Foraminiferal assemblage
Each sample weighing 80 g was disintegrated with the use of Na 2 S04 solution andnaphtha, then sieved on 200 mesh (74,um
opening) screen, and foraminifera were
picked from the residue. Of the 78 samples

Ritsuo Nomura

462

LITHOLOGY

DEPTH

Om

t
c

o
N

...o
...CD

.s::.

C.

c.
:::»

Cs.:;t:;~~~OOm8!
~~m~
CI)

lLI
-..I

CL.

:E
oq:
CI)

c
0

N

...0

.s::.

...CD

~
0
...J

G G
Figure 2. Lithology of core. A, Conglomerate; B, Coarse-grained sandstone; C, Mediumgrained sandstone; D, Mudstone; E, Alluvial
deposits; F, Not recovered interval; G, molluscs.

analyzed, 39 samples yielded foraminifera
whose stratigraphic horizons are shown in
Figure 2.
Foraminifera are generally rich and wellpreserved in mudstone, while they are usuallyrare and badly preserved in sandstone. In
all, the foraminifera of the Matsue Formation
were represented by 25 different genera.
Elphidium matsuense, n. sp. and Elphidiella
perforatum, n. sp. occur consistently throughout the core and appear to be characteristic to
the Matsue Formation. The upper part ofthe lower horizon and lower part of the upperhorizon are characterized by a greater numberof species, including Trichohyalus sp.,
Buliminella elegantissima, Buccella cf. kuro-

matsunaiensis, B. frigida, Pseudononion
japonicum. Diversity is generally low in theuppermost upper horizon. Ammonia cf.
beccarii dominates in the upper horizon andElphidium spp. and E. praesomaensis in thelower horizon (Figure 3; Appendix).
Assemblage mainly consisting of the elphidiid and rotaliid foraminifera in the lower
horizon is similar to the lower assemblage(Nonion-Elphidium-Rotalia faunule) of Tai(1959) in composition. However, three
species, Gaudryina cf. yabei Asano, Nonion
nikobarense Cushman, and Elphidium etigoense Husezima and Maruhasi, are not found,though Tai described as dominant. The
upper horizon dominated by Ammonia cf.
beccarii is not clearly correlated with Tai's
Rotalia( = Ammonia)-Bulimina faunule
because of the absence of his component taxa
such as Haplophragmoides, Trochammina
Bulimina and Nonion.
In the upper part of the lower horizon, theforaminiferal assemblage, characterized by
the aforementioned species, consists mostly of
hyaline calcareous forms but is rarely associated with porcelaneous forms represented
by dwarf specimens of Quinqueloculina. Of
particular interest is the presence of agglutinated forms such as Cribrostomoides sp.,
Plectina sp. and Proteonina compressa.
Their deformed tests are similar to those ofD E P T H
--Col

r-l

3

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..... 0

r-l

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......

U1

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---r41"I

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B"lIm/n.lI• • /og.nU,.jm.

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Murrayinella yakumoensis, n.sp .

p

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Buccella ct. kuromatsunaiensis

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."
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Elphidium izumoense,

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><

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Elphidium matsuense, n. sp.

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.,

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Pseudononion japonicum...

.. .'.
l'Elphidium

I'"''

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·11'

I"'"

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r··'····I····'··., 1· ·

g

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0'1'"

Rosalina bradyi
•••

r
rr
rr
g

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Buccel/a frigida

ij

j'''

praesomaensis, n. sp.

:l

i3'
...,

...

n. sp.

j'I

Elphidiellartr." .....,

Ammonia cf. beccarii

S

o·
:l
o
...,

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perforatum, n.sp.

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£9t

uOIJVUlJ0:f ansJVW UlOJ/ lJJal!uIUllJJoj auaJolW'668

Ritsuo Nomura

464

the agglutinated foraminifera found in theunderlying Furue Formation, in which deformed foraminifera are very abundant(Nomura, 1986b). This indicates that theagglutinated foraminifera, having a physically stout test, are derived from the Furue
Formation, which is supported by the unconformable relationship between the Matsueand Furue formations (Miyazima et al.,
1972; Yamauchi and Yoshitani, 1981;
Nomura, 1986a).

Quantitative analysis
Of 38 taxa initially identified, IS mostcommon taxa (> 4% within a sample) areconsidered here for further analysis. Q-mode
principal component analysis was applied toTable 1.

Results of principal component analyses

15 species from the Matsue Formation
Principal
Component

Eigenvalue

Cum. Var.

1

6.722

37.35

2

3.892

58.97

3

2.786

74.44

4

1.769

84.27

5

0.895

89.24

6

0.836

93.88

7

0.594

97.18

8

0.349

99.12

9

0.138

99.89

10

0.017

99.98

11 species from Matsushima Bay
Principal
Component

Eigenvalue

Cum. Var.
68.01

I

31.9652

10.306

89.94

3

3.094

96.52

4

0.809

98.24

5

0.597

99.51

6

0.131

99.79

7

0.055

99.91

reduce the census data for 24 samples yielding
more than 50 specimens to a few principal
components (hereafter PC for short) (Table
I). As described in Davis (1973), each principal component is independent and forms a
trend in the data representing particular endmember foraminiferal assemblage.
The first PC, which accounts for 37% of thetotal variance, is less value for faunal analysis. The factor scores on the first PC are all
positive and no negative scores are obtained.
As in usual cases, it only describes a deviationfrom the mean faunal composition of thesamples (Lohmann, 1978). The second PC isdefined by two end-member assemblages.
One is only represented by Ammonia cf.
beccarii, which is abundant in the upperhorizon, MT -3,5, 17, 19. The other, higher
positive factor loadings are found in MT -12,
13 and 15, is dominated by Elphidiellapraesomaensis and Buccella cf. kuromatsunaiensis (Figures 4, 5). The distribution pattern of the second PC indicates a hydrographic difference in relation to the bathymetry
as discussed later.
The third PC reveals the E. matsuense
end-member assemblage and the Ammonia cf.
beccarii and Elphidiella praesomaensis endmember assemblage. The E. matsuense
end-member has higher loadings in the lower
horizon. The fourth PC shows the EIphidium perforatum and Buccella cf. kuromatsunaiensis end-members. The accumulated proportion of these four components
accounts for 84% of the total, which may besufficient for further paleoenvironmental consideration (Figures 4, 5).
Although ecological information of newly
recognized species can not be obtained here,
Elphidium perforatum is morphologicallysimilar to E. subarcticum which is widelydistributed in the arctic to subarctic regions
and Elphidiella praesomaensis is similar to
Elphidium somaense recorded from the shallow area neighboring the bay environment ofnortheast Honshu, Japan.

899.

Miocene foraminifera from Matsue Formation

465

FACTOR LOADINGSMUD CONT.
o

50

100%

I PC2 I I PC3 I I PC4 I-1.0~

1.0 -1.0~

1.0 -1.00

10 ENVIRONMENTS
DEPTH 1m)

L...-...L--t----,"-J'

:~I

5

-50

10

B
15

-100

II~II

20

CI)

Lu
......
Q.

25

-150

:E
oq:
CI)

30

B -200250
35
39

A:inner bay facies B:middle-outer bay facies
Figure 4. Stratigraphic distribution of factor loadings of principal components 2,3, and 4, andsuggested paleoenvironment.

Paleoenvironment
Although the main species representing theend-member assemblages are extinct or newly
recognized taxa, the lithological characterand the generic composition indicate theMatsue Formation has been deposited atshallow water depth. The paleobathymetry

can be estimated by examining the bathymetric distribution of the present-day shallow water fauna with the following assumptions: the ecology of the taxa in question isclose to that of the morphologically related
living species; the ecology of the known
species is not changed significantly since the
Miocene time.

Ritsuo Nomura

466
1.0

C')

eP;Jr.JroI3IiJ ?minutJ

I-

Z

W

0.5

Z

oc..

•

~

~Efphidjum- 5<mIJt'nSt'• HI/cedla (n-gicb

o
()
....J

«

c..

i3

z

c:c..
-0.5
• ElphllJium sururr;llcum

-0,5

0.5

10

PRINCIPAL COMPONENT 2

Figure 5. Plots of foraminiferal taxa on secondand fourth principal component axes showing theend members of respective components in the Matsue
Formation. The coordinates are factor scores.

The foraminiferal assemblages werecompared to the present day faunas of theJapanese shallow water and/or bay areas in
species composition and frequency (e.g.,
Hokkaido region, Morishima and Chiji,
1952; Yoshida, 1954; northern Honshu
region, Takayanagi, 1955; Uchio, 1962;
Matoba, 1970; southwestern Honshu region,
Ishi wada, 1958; Ikeya, 1977; Kato, 1986).
In addition to these, the fauna reported fromthe littoral and lagoon areas of China (theHuanghai (Yellow) Sea and the Bohai Gulf)(Wang et al., 1985a, b, c) is also comparable
to that of the Matsue Formation in the predominance of Ammonia and elphidiid
species. Referred to these faunal associations, the Matsue Formation is clearly suggested to have been deposited in hydrographically bay facies including brackish environment. The description concerning bottom water temperature is mostly incompletein these studies, though the regions known
their surface water temperature are characterized by having a high annual temperature
range (usually in the range of ca. IY-2YC)(Takayanagi, op. cit.; Matoba, op. cit.;
Wang et al., 1985b). Among the faunas of
the above-mentioned regions, the fauna ofnorthern Honshu region such as Matsukawaura lagoon (Takayanagi, op. cit.) andMatsushima Bay (Matoba, op. cit.) shows theclosest similarity to that of the Matsue Formation. Particularly in Matsushima Bay, of 57
taxa selected for environmental discrimination of the bay, II taxa are comparable tothose from the Matsue Formation (Matoba,
op. cit., fig. 30; Table 2 of this paper).
In order to elucidate the environmental
changes of the Matsue Formation, the data
selected from Matoba's results are incorporated in the analysis using principal component comparison (Tables I and 2). The first
three components account for 97% of thevariance. Figure 6 shows the taxa contributing to the end-member associations of thesecond and third PCs. The faunal trend
described by the second PC represents thereciprocal variation in abundance between
the Ammonia beccarii end-member and thePararotalia? minuta, "Elphidium" somaense, Buccella frigida and Rosalina bradyi endmember associations.
Examining the biotopes recognized by
Matoba (1970) with the results of the respective factor loadings, the bathymetric distribution of the second PC shows a transition
around the depth of 3 m between samples
containing large proportions of the Ammonia
beccarii association and the P. ? minuta,"E". somaense, B. frigida and R. bradyi
association (Figure 7). According to
Matoba's analysis, all the samples characterized by the former association are from theinner bay facies, whereas the latter association
is from the middle to outer bay facies. In
addition to the abundant occurrence ofAmmonia species, the inner bay facies arealso generally characterized by the occurrenceof several agglutinated forms such as Trochammina, Miliammina and Goesella. The
samples containing abundant Ammonia cf.
beccarii, which are considered to indicate theinner bay facies, do not yield the agglutinatedforaminifera except for the derived taxa.
This difference may be a result of selective

899.
Table 2.

Miocene foraminifera from Matsue Formation

467

Main taxa from the Matsue Formation and morphologically similar taxa
from Matsushima Bay indicated in right parentheses. Eleven taxa from
Matsushima Bay are used for the analysis of principal component comparison.

Main species from the Matsue Formation
I.

Ammonia cf. beeearii (Linne)

2.

A. sp. A

3.

.................................. (I)5.

Bueeel/a jrigida (Cushman) .................................... (II)B. cf. kuromatsunaiensis (Shirai)(III)
Buliminel/a e/egantissima (d'Orbigny) ............................ (IV)6.
7.

E/phidiel/a praesomaensis, n. sp. . ............................... (V)E/phidium izumoense, n. sp.

8.

12.
13.

E. matsuense, n. sp.
E. perjoralllm, n. sp .......................................... (VI)
Murrayinel/a yakumoensis, n. sp ................................. (VIII)
Pseudononion japonieum Asano ................................ (IX)
Quinque/oeulina cf. jllkushimaensis Takayanagi .................. (X)Rosalina bradyi (Cushman) .................................... (XI)

14.
15.

Triehohya/us sp. . ............................................. (VII)Ul'igerina cf. akitaensis Asano

4.

9.
10.
II.

Species from Matsushima Bay (Based on Matoba, 1970)
I.
I I.
III.
IV.
V.
VI.
VII.
VIII.
IX.
X.
XI.

Ammonia beeearii (Linne)
Buecel/a frigida (Cushman)
B. makiyamae Chiji
Bliliminel/a e/egantissima (d'Orbigny)"E/phidium" somaense Takayanagi
E. subaretiellm Cushman
G/abratel/a millelli (Wright)
Pararotalia? minuta (Takayanagi)
Pseudononion japonicul11 Asano
Quinque/oculina jukushimaensis Takayanagi
Rosalina bradyi (Cushman)preservation, through which weakly cemented
agglutinated taxa are easily disintegrated.
The third PC, which is defined by EIphidium subarcticum and Pararotalia?
minuta as each end-member, reveals the trendof bottom water character represented bychlorinity and water temperature from theinner bay to outer bay facies. Samples having higher posttlve factor loadings are
obtained from the area of higher chlorinity

and those with higher negative factor loadings show a trend related to the temperatureand chlorinity (see also Matoba's figs. 16, 17,55 and 59).
The above distribution pattern of the foraminiferal taxa recognized in the modern
fauna of Matsushima Bay, is correlated withthose of the second and fourth principal
components from the Matsue Formation (Figures 5, 6) excepting the third component

Ritsuo Nomura

468
1.0

FACTOR LOADINGS
PC 2
PC 3
0

....
I-

Z

1

0.5

UJ

z
2

Bun.:dfa d ~lIrull1;I"Unjjt·J!.'I'

Am:;onia cL "',(T:lm

3

I-

,.

W

5

1's"udoflOni()l1 j3pon'CUfll

::2:

o()

..

2

: ••• Burrel/a fri~icb • [I{,hld,ella {,r.Jt'5(1(T1xn,,-,;

J:

a.

0

...J

«

0

(3

a: 6
w 7

a.

z
~ -0.5-1.0 -0.5

0

e~

° ""
oq,

0.5

.
.

1.0

-1.0 -0.5

li:>~ ~ ~a.

'ff ~.

-\~·IO- ~- - 8 p

0.0\

•
•
•

°

3::

0.5

t>

•

•

...
•
•
.
00

.

10

• Hrhidium pa{or.lIum

-0.5

9

1.0

r

t ~"

I-

<I: 8

0.5

0

~o

11

1.0

12

PRINCIPAL COMPONENT 2

Figure 6. Plots of foraminiferal taxa from
Matsushima Bay on the second and third principal
component axes showing the similar distribution
pattern to those of the Matsue Formation (Figure 5).
The coordinates are factor scores.

where comparable species such as Elphidium
matsuense are not found in Matsushima Bay.
With respect to the second PC, the Ammonia
cf. beccarii end-member assemblage and theElphidiella praesomaensis, Buccelfa cf. kuro-

matsunaiensis, Pseudononion japonicum,
Buccelfa frigida end-member assemblage ofthe Matsue Formation are respectively correlated with the Ammonia beccarii endmember and the Pararotalia ? minuta, "EI-

phidium" somaense, Buccella frigida,
Rosalina bradyi end-member associations of
Matsushima Bay (correlation coefficient r=O.
66; 0.05<p<0.02). The Elphidillm perforatum end-member assemblage on fourth PCof the Matsue Formation is comparable to theE. subarcticum end-member on the third PC
of Matsushima Bay (r=0.67; 0.05<p<0.02).
The principal component comparison reveals
that the sediments were mostly of outer bay
area facing an open shallow sea, but in two
horizons, 30-35 m (represented by MT -3,4,
5) and about 110 m, the inner bay facies wasformed where the depths were supposedly lessthan 3 m (Figure 4). However, the middle to

13

•

•

(m)

Figure 7. Depth distribution of samples
classified into respective biotopes by Matoba (1970)
showing depth related principal component 2 andprincipal component 3 explaining bottom water character. Triangle showing the sample from the inner
bay facies. Circle showing the sample from the
middle bay facies. Solid circle showing the sample
from the outer bay facies.

outer bay facies with the water of higher
average chlorinity were developed in horizons
such as 50-100 m and 145-275 m.
Concluding remarks
Aside from the foraminiferal fossils, some
megafossils have been recorded from the
Matsue Formation. Okubo (1975) reported
on the occurrence of warm brackish water
prawn fossils from 3.5 km south of this drilling site, and stated that the fossil bed might
have been deposited in a brackish bay similar
to the present-day environment of Nakanoumi or Lake Shinjiko. In addition, molluscan assemblages characterized by
Grycymeris cysyullensis from Nange,
Kamihigashikawatsu-cho, located 3.5 km
north of this site, have been considered aswarm shallow water origin (Takayasu, 1981).
In spite of uncertainty of their stratigraphic

899.

Miocene foraminifera from Matsue Formation

positions of these fossiliferous horizons, theseresults are almost consonant with the environment estimated from the foraminiferal study.
Not all of the foraminiferal taxa obtained
from this study, however, indicate a warm
water environment. Trichohyalus sp., whichis considered to be intimately related to cold
water species as described in the remarks ofthe species, reveals an influence of cold water
extending into the littoral or bay areas of the
San'in region during the deposition of the
Matsue Formation. Buccella frigida andBuliminella elegantissima are known as having a wide geographic distribution in cold totemperate-shallow seas. The southern limitsof the co-occurrence of B. frigida and B.
elegantissima in the North West Pacific are in
the northern part of the East China Sea(Wang et al., 1985c). The most common
occurrences of these species are known fromthe shallow seas ( < 20-50 m in depth) in thenorthern sea of Japan, the Okhotsk Sea, andthe Bering Sea (Fursenko et al., 1979).
Aside from the question what environmental
factor does control the distribution of B.
frigida and B. elegantissima, they are suggested to be related to cold water. Furthermore,
the new species as Elphidium perforatum andthe specimens compared to Buccella kuromatsunaiensis are thought to be morphologically related to cold water species.
Referred to the Matoba's inner bay facies,
as discussed earlier, the Ammonia cf. beccarii
end-member assemblage is supposed to haveflourished in the brackish-water and is recognized in the uppermost and lowermost upperhorizon of the core. Others are of shallow
open-sea or outer bay environment. Thisfeature indicates that the sedimentary basin
became shallower during the deposition of
the upper horizon with two fluctuations.
Basement shallowing was resulted from an
upheaval of the central ridge of the Shimane
Peninsula as already stated by Nomura(l986a) and represents the last stage oftectonic movement in the San'in region(Yamauchi and Yoshitani, 1982; Kano and469

Nakano, 1986; Nomura, 1986a).
Based on these results, paleo-Matsue Bay isconsidered a warm shallow sea with cold
water intrusions during the depositional stageof the Matsue Formation in northern Shimane Prefecture.

Systematic notes on species

Ammonia cf. beccarii (Linne)
Figures 10-1 a, b
Cf. Nautilus beccarii Linne, 1758, Syst. Nat., 10, p.
710.

Of forms referred to Ammonia cf. beccarii,
one having a small number of chambers in the
final whorl and with or without a smallumbilical plug is similar to the figured specimens as Ammonia beccarii forma 2 by
Matoba (1971, p.48, pI. 5, figs. lOa-c, Iia-c,
12a-c), the other, which have 9-12 chambersin the final whorl, limbate sutures and umbilical plug falls within a range of young A.
tochigiensis (= Rotalia tochigiensis Uchio,
1951 ).

Bolivina sp. A
Figure 10-3

Small-sized specimens are rarely found In
sample MT -2.

Buccella frigida (Cushman)
Figures 1O-8a-c, II

Pulvinulina frigida Cushman, 1922, Canad. BioI.,
Contr., no. 9 p. 12.
Buccella frigida (Cushman). Andersen, 1952,
Washington A cad. Sci., Jour., vol. 42, no. 5, p. 144,
figs. 4a -6c.

This species occurs In close association
with Elphidiella praesomaensis, Buliminella
elegantissima and Elphidium izumoense inthis formation and is common in the lower
part of the upper horizon.

Ritsuo Nomura

470

Bueeella cf. kuromatsunaiensis Shirai
Figures 10-7a, b
Cf. Buccella kuromatsunaiensis Shirai, 1960, Jour.,
Hokkaido Univ., Fac. Sci. ser. 4, Geol. Mineral.,vol. 10, no. 3, p. 540-541, pI. 2, figs.2a-c.

The specimens identified here are comparable to Bueeella kuromatsunaiensis from the
Pleistocene deposits (originally described as
the Pliocene) of Kuromatsunai, southern
Hokkaido, in having an average thickne~s/
maximum diameter ratio of 0.52 and veryslightly raised walls near the umbilicus.
However, the specimens from the Matsue
Formation consist of 7-9 chambers in the lastwhorl and have more inflated ventral chambers in comparison with B. kuromatsunaiensis. Ventral feature of this species is somewhat similar to those of Bueeella tanaii andBueeella makiyamae Chiji, but the latter
species have the strongly convex dorsal test.
The Matsue specimens are noted to havenot supplementary apertures on the posterosutural margin of each chamber on the ventral
side. The presence of the supplymentary
apertures is one of the diagnostics of thegenus Bueeel/a, though the species is tentatively allocated to this genus.

B. cf. kuromatsunaiensis occurs abundantly in several horizons of the boring core andis one of the main constituents of the assemblage.
Buliminella elegantissima (d'Orbigny)
Figures 9-5a, b

Bulimina elegantissima d'Orbigny, 1839, Voy. Amer.
Merid., Foraminiferes, vol. 5, pt. 5, p. 51, pI. 7, figs.
13,14.
Buliminella elegantissima (d'Orbigny). Matoba,
1970, Sci. Rep., Tohoku Univ., 2nd ser. (Geol.),
vol. 42, no. I, p. 50, pI. 3, fig. 24.

Around the seas of Japan, modern
Buliminella elegantissima occurs commonlyin the cold to temperate and shallow water

regions (e.g., Nomura, 1982). Ishiwada(1964) reported the Bueeella frigidaBuliminella elegantissima assemblage fromshallow water off Kushiro, Hokkaido, as a
subarctic coastal assemblage. Recently, Oki(1989) suggested that B. elegantissima is originally a cold water species and the modern
species living in the shallow seas off southwestern Japan might be adapted to warm
water as a relict species. Besides the seasaround the Japanese Islands, this species isfound in the East China Sea and the South
China Sea (Wang et at., 1985c).
Buliminella elegantissima from the Matsue
Formation occurs in the upper part of thelower horizon and the upper horizon, being
in association with Elphidiella praesomaensis.

Cribrostomoides sp.
Like that of Pleetina, poorly preserved
specimens are found in the sample MT -14.
The specimens are judged as reworked fromthe underlying formation, where Cribrostomoides cf. erassimargo is the main constituent in the Furue Formation (Nomura, 1986b).

Pseudononion japonieum Asano
Figures 9-la, b, 2a-c

Pseudononion japonicum Asano, 1936, Jour., Geol.
Soc. Japan, vol. 43, no. 512, p. 347, text-figs. a-c.
Pseudononion japonicum Asano. Saunders andMliller-Merz, 1982, Jour. Foram. Res., vol. 12, no.
3, p. 262, pI. I, figs. 1-3.

Compared with the original figures ofAsano, the Matsue specimens have a thicker
test; the ratio of test thickness to length (T /L) is 4 in the original description, whereas thepresent specimens show an average ratio of
2.3. However, this ratio is almost equal to
the topotype specimens redescribed by Saunders and Milller-Merz (1980).
SEM photographs show the smooth test
surface with grooved sutures near umbilicus
filled with small pustules and do not show the899.

Miocene foraminifera from Matsue Formation

471

furrowed nature of test surface caused byslight inflation of chambers, which are usually recognized in typical Pseudononion

Rep., Tohoku Univ., 2nd ser. (Geol.), v.42, no. I,
p. 60, pI. 4, figs. 8a -c.

japonieum.
Pseudononion japonieum is common in theThis shallow-water species is rarely foundin the upper part of the lower horizon and theupper horizon.

Pliocene to Recent deposits of Japan whereas
the Miocene forms have not been hitherto
illustrated.

Pleelina sp.
Figure 9-10

A broken incomplete specimen is found insample MT -14. The specimen is also compressed due to fossilization. This feature isvery close to specimens from the underlying
Furue Formation, suggesting that this specimen has been derived from the Furue Formation.

Quinqueloeulina cf. fukushimaensis
Takayanagi
Figures 10-6a, bcr.

Quinqueloculina fukushimaensis Takayanagi,
1955, COnlr., Inst. Geol. Pal., Tohoku Unil'., no.
45, p. 51, figs. 26a -c.

Although Quinqueloeulina fukushimaensis
was originally described as having the wall
cemented with very fine sand grains, the wallsof holotype are covered with minute pits.
Several comparable specimens from the Matsue Formation show such a granular appearance caused by light reflection on minutely
pitted wall surface.

Triehohyalus sp.
Figures 10-lOa, b, 12a-c

The mature specimens are characterized byhaving a large trochoid test consisting of avery strongly convex dorsal side and a flat
ventral side, indistinct apertural foramen,
flushed sutures, and ventral knobs (Figures
1O-12a - c). The test of younger specimens
shows a centrally situated aperture withradial striations (Figures 10-lOa, b), whereas
the dissected test without last few chambers
reveals the trochospiral chamber arrangement
and interiomarginal apertural foramen withfine striations on apertural face.
The walls of this form is thick and opticallyradial in texture. These diagnostics seem tobe somewhat differentiated from the definition of the genus Triehohyalus; nevertheless,the present form is tentatively assigned to thisgenus, following the description of Voloshinova et al. (1970).
Voloshinova et al. (1970) recorded similar
form to the present one from the Pliocene
deposits of Sakhalin as Triehohyalus bartfelli, which has been known as cold water
species. Similar form, Glabratella orn a tissima (Cushman), is also reported by Erskian
and Lipps (1987) from the Recent coastalzone of northern California.

Rosalina bradyi (Cushman)
Figures IO-9a-c

Uvigerina cf. akitaensis Asano
Figures 9-11

Discorbis globuralis var. bradyi Cushman, 1915, U.
S. Nat. Mus., Bull., no. 71, pt. 5, p. 12, pI. 8, figs.
la-c.
Discopulvinulina bradyi (Cushman). Asano, 1951,
Illust. Cat. Japan. Tert. Small. Foram., p.4, textfigs. 25, 26
Rosalina bradyi (Cushman). Matoba, 1970, Sci.

cr. Uvigerina akitaensis Asano, 1950, Illust. Cat.
Japan. Tert. Small. Foram., pt. 2, p. 28, figs. 60-62.

The small specimens showing somewhat
eroded test surface are rarely found in the

Ritsuo Nomura

472

upper horizon. In their lobulate character ofthe periphery, these specimens are compared
to Uvigerina akitaensis.

Description of new species
Order Foraminiferida Eichwald, 1830
Suborder Rotaliina Delage
and Herouard, 1896
Superfamily Glabratellacea Loeblichand Tappan, 1964
Family Glabratellidae Loeblichand Tappan, 1964
Genus Murrayinella Farias, 1977

Murrayinella yakumoensis Nomura, n. sp.
Figures IO-2a, b, 4a, b, Sa, b

Diagnosis. - Plano-convex test with n umerous short spines. Periphery rounded, but not
inflated. Ventral sutures depressed and filledwith granular shell materials near the umbilicus.
Description.- Test small, generally planoconvex, dorsal side flat to slightly convex;
peripheral margin rounded and lobulated,but narrower in the earlier formed portion;chambers distinct, inflated, five to six in !ast
whorl, more rounded in the final one;sutures slightly limbate on dorsal side but
ventrally depressed; chambers tend to separate near umbilicus, but generally obscuredby hispid small spines; wall rough, withnumerous short spines, and coarsely perforated; aperture obscure, an elongate, lowarched opening at the based of septum about
midway of ventral side; wall translucent,radial in texture.
Type and materials. - Holotype, D ESS
88001, Figures 10-2a, b, from sample MT-13
of boring core, Matsue Formation, late Middle Miocene; paratype, DESS 88002, Figures
1O-4a, b from the same sample; paratype,
DESS 88003, Figures 1O-5a, b, from the same
sample.
Size and measurements. - Holotype, maxi-

mum diameter 0.32 mm, thickness 0.19 mm ;24 para types, maximum diameter 0.19-0.32
mm (av., 0.22 mm), thickness 0.09-0.19 mm(av., 0.13 mm).
Remarks. - This new species resembles
Rotalia? minuta Takayanagi ( = Pararotalia? minuta of Matoba, 1970 = Murrayinella minuta of Takayanagi and Hasegawa, 1987) in its test size and surface
hispidity. According to Matoba (1970),
Pararotalia? minuta has nearly flat dorsal
and strongly convex ventral sides and almost
acute periphery with pustulous fringe except
for the last few chambers of some specimens.
Therefore, Murrayinella yakumoensis is distinguished from P.? minuta by having arounded periphery without pustulous fringeand coarse perforation.
This new species resembles M. murrayi (=Rotalia murrayi Heron-Allen and Earland),but differs from it in the less globular chambers and not deeply depressed sutures as wellas the covering of pustulous materials on theumbilicus.
Superfamily Rotaliacea Schultze, 1854
Family Elphidiidae Schultze, 1854
Subfamily Elphidiinae Saidova, 1981
Genus Elphidium de Montfort, 1808

Elphidium izumoense Nomura, n. sp.
Figures 9-3a, b, 4a, b; 11-11,12.

Diagnosis. - Compressed test with nearlyflat umbilicus. Umbilicus with indistinct
boss-like structure. Chambers fusing in aring around the umbilicus.
Description.- Test compressed, nearly circular, not lobulate in side view; peripheryrounded, nearly parallel in edge view; umbilical region flat, with indistinct boss-likestructure and covered with less developed
granular shell materials; chambers distinct,
not inflated, 11 in the last whorl, fusing in aring around the umbilicus; sutures distinct,
grooved, but indistinct by forming a sutural

899.

Miocene foraminifera from Matsue Formation

canal around the umbilicus, without retral
process; wall smooth, very finely perforate,
optically granular in texture; aperture indistinct by the presence of granular shell materials; previous apertures rounded, two or
three openings at the base of the inner marginof the last-formed chamber.
Type and materials.-Holotype, DESS
88004, Figures 9-4a-c, from sample MT -7 ofboring core, Matsue Formation, late Middle
Miocene; paratype, DESS 88005, Figures 93a, b, from the same sample.
Size and measurements. - Holotype, maximum diameter 0.22 mm, thickness 0.09 mm ;20 para types, maximum diameter 0.21-0.35
mm (av., 0.26 mm), thickness 0.09-0.14 mm(av., 0.11 mm).
Remarks.-In lacking retral process or fossetts and the development of umbilical flaps,
the external feature of this new species apparently coincides with the generic diagnoses of
Paleogene Protelphidium Haynes redescribedby Banner and Culver (1978). However, inthe possession of the intercameral lacunae
and sutural canals around the umbilicus
which intercommunicate with the umbilicalspiral canals (Figures 11-11, 12), the present
new species is assigned to the gen us El-

phidium.
In appearance, umbilical structure of thisspecies resembles that of Astrononion. However, interiomarginal aperture is not a narrowslit but a row of small openings, which indicates this taxon is not assignable to Astrononion.
Elphidium izumoense, n. sp. is distinguished from Elphidium simplex Cushman by
the development of ring-like structure aroundthe umbilicus.
Elphidium matsuense Nomura, n. sp.
Figures 9-6a, b, 7a-c; 11-5-7

Diagnosis.- Test smooth, except for slightly depressed umbilicus with granular shellmaterials. Sutures near the umbilicus

473

depressed, without sutural pores. Sutural
canals only formed in the umbilicus. Aperture consisting of a row of small rounded
openings.
Description. - Test compressed, almost completely involute, bilaterally symmetrical;
peripheral margin rounded, not lobulate;umbilical region slightly depressed, with
granular shell materials, which extend to
apertural area; chambers distinct, not inflated, increasing gradually in size as added, 7 to
8 chambers in the last whorl; sutures flushwith surface excepting final one and umbilicus, where canals are formed by a umbilical flap-like structure, curved toward the
periphery, without retral process or sutural
bridges; wall smooth, very finely perforate,
polished, originally optically granular in texture; aperture interiomarginal, a row ofabout four rounded openings at the base ofapertural face, which is more or less hidden
by tuberculated shell materials on the final
chamber.
Type and materials. -Holotype, DESS
88006, Figures 9-7a-c, from samples Mt-17
of boring core, Matsue Formation, late Middle Miocene; Paratypes, DESS 88007, Figures 9-6a, b. from the same sample.
Size and measurements. - Holotype, maximum diameter 0.38 mm, thickness 0.16 mm;
27 paratypes, maximum diameter 0.16-0.54
mm (av., 0.34 mm), thickness 0.08-0.21 mm(av., 0.15 mm).
Remarks. - This new species may be assigned to the genus Haynesina by the featureof intercameral lacunae and umbilical tuberculation. However, the intercameral lacunaechange to sutural canals around the umbilicus
and do not intercommunicate with thelatero-umbilical supplementary apertures asredefined in the Haynesina (Banner andCulver, 1978), but only internally communicate with umbilical spiral canals (Figures lI5,6). Usually the latero-umbilical supplementary apertures are not clearly observablein this species (Figure 11-7).
In addition to these features, the wall ofRilsuo Nomura

474

Figure 8. Two different optical wall characters of Elphidium malsuense.
1 shows a typical granul ar texture, whereas 2 depicted by the previous chamber wall
is similar to an indistinctly radial texture. Crossed nicols. Scale: 50 j.lm.

this species is commonly optically granular in
texture but in previous chamber with layered
walls it shows an intermediate texture
between granular and radial (Figure 8).
This species differs from Aslrononion umbilicalUlum Uchio in the shape of apertureand the absence of rounded openings associated with an umbilical flap.

Elphidium pelforatum Nomura , n. Sp.
Figures 9- 9a , b, 12a, b, 13 ; 11 - 1- 4

Diagnosis. - Test with coarse perforation.
Umbilicus covered with granular shell materials. Sutures limbate, without sutural pores.
Sutural canals only formed in the umbilicus.
Apertural openings indistinct.
~

Description . - Test compressed, su bcircularin side view ; periphery rounded and slightly
lobulated ; umbilical region slightly depressed or almost flat , covered with granular shellmaterial extending partly to the base of apertural face; chambers seven to eight in the lastwhorl ; sutures limbate, very slightly if at all
depressed , without retral process and suturalpores; wall usually transparent, with distinct
pore-lining ; aperture of multiple openings at
the base of apertural face of the last formedchamber, but usually indistinct by the presence of granular shell materials.
Type and malerials. - Holotype, DESS
88008, Figures 9- 9a , b, from sample MT - 10of boring core, Matsue Formation , late Middle Miocene ; paratype, DESS 88009, Figures
9-12a, b, 13, from the same sample.

Figure 9. I, 2, Pseudononion japonicum Asano. la, b ; SEM photo, MT - 13, x 94. 2a, b; optica lphoto, MT -13, x 112. 3,4, Elphidium izumoense Nomura, n. sp. 3a, b ; SEM photo, MT - 13, X 94. 4a, b ;holotype, optical photo, MT - 13, X 112. 5. Buliminella eleganlissima (d'Orbign y). optical photo , MT13, X 112. 6,7, Elphidium matsuense Nomura, n. sp. 6a, b ; SEM photo , MT - 17, X 81. 7a - c ; holotype,optical photo, MT - 17, X 112. 8, Elphidiella praesomaensis Nomura, n. sp. optical photo , holotype, MT13, X 112. 9, 12, 13, Elphidium pel/ora/um Nomura , n. sp. 9a, b ; optica l photo, holotype, MT - 10, X I 12.
12a, b ; SEM photo , MT - 10, X 105. 13 ; SEM photo showing pustule on umbilical portion , X 240. 10,
Plectina sp. SEM photo, MT - 14, X 53. II, Uvigerina cf. akilaensis Asano. SEM photo, MT - 10, X 120.

899.

Miocene foraminifera from Matsue Formation

475

476

Ritsuo Nomura

Size and measurements. - Holotype, maximum diameter 0.32 mm, thickness 0.13 mm ;24 paratypes, maximum diameter 0.15-0.32
mm (av., 0.21 mm), thickness 0.09-0.14 mm(av., 0.12 mm).
Remarks. - This new species is similar to
Elphidium subarcticum Cushman in having
the sutural and umbilical spiral canals as wellas the umbilical tuberculation, but differs in
the absence of sutural pores and retral process, and by having coarse perforation. In thepresence of the umbilical tuberculation, thisspecies is further closely related to the arctic
and boreal species such as Cribroelphidium
granatum (Gudina) depicted by Gudina andLevtchuk (1989) and Perfectnonion obscurus(Voloshinova) reported by Voloshinova etal., (1970) from the Pliocene of Sakhalin.
However, E. perforatum can be distinguishedfrom C. granatum by having a limited distribution of the tuberculation on the apertural
face as well as the umbilical region and theabsence of the sutural pores. It is also distinguished from P. obscurus by having fewer
chambers in the last whorl and slightly
depressed sutures around the umbilicus. As
far as the figured holotype and paratype areconcerned, Elphidium nakanokawaense Shirai (1960) from the Pleistocene deposits(originally described as the Pliocene) ofKuromatsunai, southern Hokkaido, isanother species similar to this new one.
Examined the specimens from near the type
locality, however, it is poirited out that E.
nakanokawaense is not closely related to E.
perforatum, but rather related to E. subarcticum in the development of the tuberculation in the umbilical and the sutural regions
and in the possession of the minute suturalpores.
The retral process has been recognized as
the diagnostic feature of the genus Elphidium.
Hansen and Lykke-Andersen (1975, p.20)
stated that all degrees of development ofretral processes exist and stressed that retral
process is a poor character for distinguishing
the Elphidium group from similar groups.
Based on their observations, this new species
is here assigned to the genus Elphidium.
As far as known species from Japan andneighboring areas are examined, it seems thatE. perforatum is related to arctic or boreal
water.

Elphidiella praesomaensis' Nomura, n. sp.
Figures 9-8a, b; 11-8-10

Diagnosis.- Test with rounded periphery.
Apertural face decorated with numerous
tuberculations. Sutures flushed with surface,with weak double row of small pores internally connected with sub sutural canals.
Description.- Test medium, nearly circularin side view and elongate oval in edge view;
periphery rounded, not lobulate; umbilicalregion slightly depressed; chambers distinct,
increasing gradually in size as added, 8 to 9
chambers in the last coil; sutures gently
curved toward periphery, almost flush withsurface, with very weak double rows of small
pores, which often indistinct; wall smooth,very finely perforate, optically. granular in
texture; aperture consists of several roundedinteriomarginal openings, usually covered
with numerous tuberculations.
Type and materials. - Holotype, DESS
88008, Figures 9-8a, b, from sample MT -13~
Figure 10. 1, Ammonia cf. beccarii (Linne). SEM photo, MT -3, x 94. 2, 4,5, Murrayinella yakumoensis Nomura, n. sp. 2a, b; holotype, optical photo, MT -13, X 112. 4a, b; SEM photo, MT -13, X
105. Sa, b; SEM photo, MT -13, X 137. 3, Bolivina sp. A. SEM photo, MT -2, X 194. 6, Quinqueloculina
cf. fukushimaensis Takayanagi. . SEM photo, MT -15, X 94. 7, Buccella cf. kuromatsunaiensis (Uchio).
SEM photo, MT -13, X 120. 8, 11, Buccella frigida (Cushman). 8a-c; Optical photo, MT -10, x·112.
11; SEM photo, l\1J' -I 0, X 137. 9, Rosalina bradyi (Cushman). Optical photo, MT -14, X 112. 10, 12,
Trichohyalus sp. lOa, b; SEM photo, juvenile specimen, MT -14, X 106. 12a, b; SEM photo, MT -14, X
38.

899.

Miocene foraminifera from Matsue Formation

477

478

Ritsuo Nomura

899.

Miocene foraminifera from Matsue Formationof boring core, Matsue Formation, late Middle Miocene.
Size and measurements. ~ Holotype, maximum diameter 0.35 mm, thickness 0.18 mm ;20 paratypes, maxim urn diameter 0.21-0.38
mm (av., 0.27 mm), thickness 0.12-0.20 mm(av., 0.15 mm).

Remarks. ~ Elphidie/lapraesomaensis

shows the double rows of sutural pores internally connected with subsutural canals (Figure 11-9), which are not so typical but mostcharacteristic feature for the gen us.
In appearance, this species is similar to
Elphidiella momiyamensis Uchio (1951) occurring commonly from the early Middle
Miocene deposits of Japan. However, to potypes of E. momiyamensis are characterizedby having large and robust tests with usually
10-12 chambers. These diagnostics of E.
momiyamensis are differentiated from thoseof this new species.
Despite of differently allocated generic
position, this species is closely related to thepresent day species Elphidium somaense described by Takayanagi (1955) from the shallow bay area of Matsukawaura, Fukushima
Prefecture, in its chamber arrangement andsomewhat depressed umbilicus. Moreover,Elphidiella praesomaensis is characterized byhaving numerous small tuberculations
around the aperture (Figure 11-8, 10), which
is similar to those of the holotype as well as
the subsequently figured specimen by Matoba(1970, p. 53; pI. 7, figs. II a, b, 12a, b: "EIphidium" somaense), though no mention ofthem is made in the original description andremarks. Nevertheless, Elphidie/la pra-479

esomaensis is differentiated from E. somaense in its greater test size and double rows ofsutural pores mentioned above, suggesting achronological differentiation between them.
Acknowledgments
I express my gratitude to Prof. Y. Takayanagi and Dr. S. Hasegawa, both of Tohoku
University, and Prof. Y. Matoba of Akita
University, for their critical comments on thismanuscript.
I am also grateful to Mr. N. Watanabe,
Director of the Nishinippon Kensetsu Consultant Co., and Prof. K. Miura of Shimane
University for providing the core samples andmany facilities for core description. Mr. J.
Pospichal of Florida State University kindly
read the earlier draft of this manuscript.
This work is partly supported by the Grantin-Aid of the Ministry of Education, Science
and Culture of Japan (Nos.58740385 and62740466).
References
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Japan, vol. 43, no. 512, p.347-348.
Banner, F.T. and Culver, S.J., 1978: Quaternary
Haynesina n. gen. and Paleogene ProtelphidiulIl
Haynes; their morphology, affinities and distribution. Jour. Foram. Res., vol. 8, no. 3, p. 177207, pis. 1-10.
Davis, J.e., 1973: Statistics and data analysis in
Geology. John Wiley and Sons, 550 p., NewYork.
Erskian, M.G. and Lipps, J.H., 1987: Population+- Figure II. 1-4, Elphidium per/orall/m Nomura, n. sp. 1; dissected specimen, X 125. 2; enlargement of no. I showing sutural canals (SC), X 250. 3; internal structure showing umbilical spiral canal(USC) of penultimate chamber, X 300. 4; external structure showing apertural pustules, X 350. 5-7,
Elphidium matsuense Nomura, n. sp. 5; dissected specimen showing umbilical spiral canals (USC), X 150.
6; internal structure showing sutural canals (SC) and umbilical spiral canal (USC), X 300. 7; internal
structure showing previous apertural foramen, X 300. 8-10, Elphidiella praesomaensis Nomura, n. sp. 8;
specimen without final chamber showing external apertural pustules and penultimate apertural foramen(AF), X 250. 9; internal structure showing subsutural canals, X 250. 10; internally viewed final apertureof no. 8, X 250. II, 12, Elphidium izumoense Nomura, n. sp. II; specimen without final and penultimate
chambers showing internal apertural foramen and openings of umbilical spiral canal (USC). X 400. 12;
obliquely viewed no. 11 showing umbilical wall. x 350.

Ritsuo Nomura

480

dynamics of the foraminiferan Glabratella ornatissima (Cushman) in northern California.
Jour. Foram. Res., vol. 17, no. 3, p. 240-256, pI.
I.

Fursenko, A.V., Troitskaya, T.S., Levtchuk, L.K.,
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Ishiwada, Y., 1958: Studies on the brackish water
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abstracl)- - , 1964: Benthonic foraminifera off the Pacificcoast of Japan referred to biostratigraphy of the
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Southwest Japan, in the light of radiometricdating. Geol. Surv. Japan, Bull., vol. 36, no. 8,
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Kato, M., 1986: Recent shallow water foraminifera in
Hiroshima Bay, Seto Inland Sea, Japan. In,
Matoba, Y. and Kato, M. eds., SlUdies on

Cenozoic

Ben/hic

Foraminifera

inJapan.

Akita Univ., Akita, p. 27-42. (in Japanese)
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Lohmann, G.P., 1978: Abyssal benthonic foraminifera as hydrographic indicators in the western South Atlantic Ocean. Jour., Foram. Res.,
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Matoba, Y., 1970: Distribution of Recent shallow
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pis. 1-8.
Miyazima, M., Nagashima, H. and Onishi, I., 1972:
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1-3.
Nomura, S. and Hatai, K., 1939: Fossil mollusca
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from areas around Japan. In, Takayanagi, Y.
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Okubo, M., 1975: Fossil prawn from the Miocene
Matsue Formation. Mem., Nat. Cult. Res.,
San-in Region, no. 15, p. 211-216. (in Japanese)
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Saunders, J.B. and Mliller-Merz, E., 1982: The genus
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Tai, Y., 1952: Stratigraphy and geological structureof the central area of Shimane Peninsula,
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Miocene foraminifera from Matsue Formation

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Takayasu, K., 1980: Fossil from Nange, Matsue
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481

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movements in the progressive stage of the GreenTuff basins: Taking the case of the Miocene
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abstract)
Yoshida, S., 1954: Studies on the foraminifera ofbrackish waters III: The foraminifera of Lake
Saroma. SllId., Geol. Miner. Ins/., Tokyo Univ.
Educ., no. 3, p. 149-158, pI. I.

Matsue t0i'I, Furue tli'I, Fujina ;(P;t::g, Wakurayama fp~liLlI, Teratsu
Kawatsu )11 $, Kuroda ~ 83, Yada J;R: 83, Asakumi-cho illJllfJ lilT, Nange
Kamihigashikawatsu-cho J:.Jf[)II$1IlJ

m*,
~$,

~t.&Yf<t0i'I~O)cpMcp!fJT1i:J:1&MO)~JL!R: t0i'Im{ij~CP'L' c L t-:{tUm1'i'h::'ft, cpMcp!fJT
1i:J:1&MO)m$Plt~ J: I) t.c Q t0i'I~ tJ:5t;(P-t Q0 t0i'I~ It ~ td: -c·Lli~.ttl!.~O) CP!fJTWE~J:. $~ C vct\'U~tf.W:.~nn -C ~ t-:I::. t tJ'tJ'n Gf, tI~mO)1l5Cf':' -t-5ttJ:lif1'4tJ:W?~ ~ n-c~,tJ:tJ'-?t-:o ~@], 7tim(WEJ:llU.:.J: -?-c~Gnt-: I ; f - ~ '/ ~'ilit1'4I':'J: I) 38 !J ~ -IT0)!fl;1:.~
JL.:E.1r.:ti~~;g&,)Q ~ ctJ:-e~t-:O)-c·tI~mmtJT~IT-?t-:o i£1±l Lt-:~JL.:E.ft Ammonia cf.

beccarii, Elphidium izumoense, n. sp., Elphidium matsuense, n. sp., Buliminella elegantissima, Buccella cf. kuromatsunaiensis, Elphidiella praesomaensis, n. sp., Elphidium per/oratum, n. sp., Pseudononion japonicum, Trichohyalus sp. ~ ~~~fi c L -C ~'Q ~{:sLi'fJ5t;(P -C' ItJ:. $ f':' A. cf. beccarii r:f. ~ tJ:, T $ c J:. $ 0) - $ -C' E. per/ora tum r:f.~, E.
praesomaensis r:f.~, E. matsuense r:f.~tJ:3B:i¥-t Q ~ 0) J: ? tJ:r:f.~*J3.Pltlt, ~1bLfi 0) jii'fJ00t.cJ:t~~-t Q ~~ I) Jf[~t.ttl!.::JJ*fl$,Ej!:0)t0)lli1Ii·N0~~O)m1:.~JL!Rr:f. c mPltp;j!i1¥tJ::j-.jll1':>-C
1bL -C ~'Q ~ -c'ff El ~ Q 0 { - 0) t-: 111':> 1&* Matoba (\970) 0) ~ ;t.. ~ J: I)~!v t-=: I I !J ~ -ITf':' -::>~ '-C ::tPlt5tJ:t~~IT -? tdi5!l, t0i'I~0) T$~$ft~ 0 p;j:7j.O)JW~~m~~ L, J:.$
It7ti*tJ: 3 m ~!tO)p;j~i'fJ~m""c ~{r. L -C ~'-? t-: c::1j;z GnQ o vt3fEt0i'I~ltj'J,1r.:tir:f.
~~~~-.x. 1::"1r.E J: I) m~tJ:JW~~mtJ:~~WEJ ~ n -C ~ ,t-:O) f.:.M L, ~@]~~ L t-:i'JJL.:E.r:f.
~ft, ~i5fE*fU' I) -c'tJ: *14J7tlJ1!.0)~f! t ~vt-c l ,t-: ~ c ~~-totitHf1::cn<Ritsuo Nomura

482

Occurrences of foramini leral taxa from the Matsue Formation.

Appendix.
Stratigraphic horizon

Upper

Foraminiferal
Taxa/Samples

MTI

2

3

4

5

6

7

8

10

II

12

Median Depth ofSample (m)

29.5

30.5

31.6

32.3

35.5 49.5

53.5

56.0 64.3 69.5

70.5

93.4 9S.5

913(Agglutinated tests)
Cribrostomoides sp.
Plectina sp.

Proteonia compressa
Textularia sp.

14

15

16

17

18

19

99.5 100.4 103.8 10S.4 109.5 110.5

I
I
I
I

(Porcelaneous tests)

Quinqueloculina
polygon aQ. cf. fukushimaensis(Calcareous hyaline
tests)
Ammonia cf. beccarii
A. spp.
Bolivia sp. A
B. sp.

2
3

7

445

146

I

201

37

2S

I

37

I

21

127

I

I

91

I

3
I

Brizalina sp.
Buccella frigida
B. cf. fniglda cal ida
B. cf.
kuromatsunaiensis
B. sp.

5

24

21

I

I

3

I

34
I

3

Buliminella
elegantissima
Elphidiellapraesomaensis
Elphidium cf.
excavalum
E. izumoense
E. matsuense
E. perforatum
Epistominella pulchella
Fissurina
cucurbitasema
Gavelinella sp.
GUllulina pacifica

2

II

4

15

9

25

14

2

5

12

26
3

7

46

8

26

3

75

175

I

I

16

23

7

22

10

22

62

I

6

7

43

9

44

274

21

18

9

11

7

I

II

II

22

38

54

2
14

23
I

4

2
3

4

221

71

63

2

8

2

5

24

13

33

2

1

2

I
I

I

I

2

G. sp.

I

lslandiella sp.
Murrayinella
yakumoensis
Nonion sp.
Pseudononion
japonicum

I

I
I

10

2

23

34

4S

12

S2

2
5

20

Rosalina bradyi
R. sp.
Trichohyalus sp.
Trifarina sp.
Uvigerina cf. akitaensis

5

2

9

7

22

18

2

10

2
I

5

41

I

I

I

I

7

I
I

U. sp.
Miscellaneous(agglutinated)
Miscellaneous(calareous)

4
2
I

Total counted

12

4

475

157

232

49

SO

Amount of sample (g)

80

SO

34

80

SO

80

80

15

110

265

119

202

673

114

127

S6

256

232

156

SO

SO

SO

SO

39

80

SO

SO

80

SO

SO

SO

899.

Miocene foraminifera from Matsue Formation
Lower

Stratigraphic horizon
Foraminiferal
Taxa/Samples
Median Depth ofSample (m)

483

MT-

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

115.0 133.6 138.6 144.3 146.7 152.6 165.5 173.4 175.3 185.4 194.7 197.5 215.7 230.4 265.4 266.5 270.5 272.5 273.5 276.5(Agglutinatedtests)
CribroslOmoides
sp.
P/eclina sp.
Proteonina

compressa
TexllI/aria sp.
(Porcelaneous
tests)
QlIinqlle/oculinapO(llgona
Q. cf.
fllkllshimaensis(Calcareoushyaline tests)
Ammonia cf.
becarii
A. spp.
Bolil'ina deccllsata
B. sp.

3

I

Brizalina sp.
Bliccel/a frigida
B. cf. frigida cal/daB. cf. kllromalsllnaiensis
B. sp.

I

2

6

I

I
I

5

II

16

4

19

4

16

178

I

24

I

G. sp.
Is/andiel/a sp.
Mlirrayinel/ayakumoensis
Nonion sp.
Pseudononion
japonicum

142

eXQl'alum

E. perforatum
Episolminel/apulchel/a
Fissurins
cucubitasema
Gavelinel/a sp.
GUllu/ina pacifica

I

I

I

Bliliminellae/eganlissima
EE/phidiel/apraesomaensis
E/phidillm cf.
E. izumoense
E. malsuense

81

3

5

I

18

3

13

I

I

I

3

I

83

I

114

I

4

53

17
92

33

24

I

4

2

I

4

6

12

3

2

II

2

10

38

2
97

24

12

I

8

235
59
170

40

I

Ritsuo Nomura

484

Foraminiferal
Taxa/Samples
Median Depth ofSample (m)

MT-

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

34

115.0 133.6 138.6 146.7 152.6 165.5 173.4 175.3 185.4 194.7 194.7 197.5 230.4 230.4 265.4 266.5 270.5 272.5 213.5 276.5

Rosa/ina bradyi
R. sp.
Trichohya/us sp.
Trifarina sp.
Uvigerina cf.
akilaensis

4

U. sp.

I

Miscellaneous(agglutinated)
Miscellaneous(calcareous)I

3

Total counted

4

7

2

16

50

416

I

4

91

57

3

7

149

3

19

63

III

188

40

390

Amount of sample
(g)

80

80

80

80

80

80

80

80

80

80

80

80

80

80

80

80

80

80

80

39

Trans. Proc. Palaeont. Soc. Japan, N.S., No. 158, pp.485-512, 16 Figs., June 30, 1990

900. NOTES ON A CRETACEOUS BIVALVEINOCERAMUS (PLATYCERAMUS) MANTELLIDE MERCEY FROM JAPAN*
MASA YUKI NODA
Fukagochi 5 kumi, Oita, 870
andSEIICHI TOSHIMITSU
Geological Survey of Japan, Tsukuba, 305

Abstract. Based on a number of specimens of Inoceramus (Platyceramus) mantelli deMercey, 1877, from Hokkaido several quantitative characters were examined biometrically.
The specimens of I. (P.) mantelli from Japan have been hitherto ascribed to I. (P.)
yubariensis Nagao et Matsumoto, 1940. From the precise comparison between the specimens from Europe and Japan, the morphological difference is so slight that specific distinction does not seem necessary. Thus the specific name I. (P.) yubariensis Nagao etMatsumoto falls in a junior synonym of I. (P.) mantelli de Mercey. Stratigraphically I.
(P.) mantelli from Europe and eastern contiguous regions ranges throughout the Coniacian,whereas the range of this species in Japan is from the Upper Coniacian to the Santonian.
The ancestry of I. (P.) mantelli is as yet uncertain, but this species may be the common
ancestor of various species of Inoceramus (Platyceramus) from the Santonian andCampanian.
Key words. Inoceramus (Platyceramus) ma ntelli , yubariensis, synonym, Upper
Coniacian, Santonian.

an independent species. Since then, I.
yubarensis [ sic] has been listed in several
papers without giving a revised definition andclear extent of variation.
This paper is to clarify the systematic relationship between I. mantelli and l. yubariensis. For this purpose we made field works
together with T. Matsumoto in the type areaof Hobetsu, and Noda (M.N.), with T. Matsumoto (T.M.) and others, in the Ikushumbets (Mikasa) area. Meanwhile, Toshimitsu(S.T.) obtained a considerable number of
specimens during his field work in the Haboro area. In addition, A. Inoma's collection
from the Kotanbetsu area, kept in Kyushu
University was provided for this study byIntroduction

Inoceramus mantelli de Mercey, 1877
occurs commonly in the Coniacian of Europe
and contiguous regions of Asia, but thisspecies has been undescribed in Japan.
On the other hand, I. incertus var. yubariensis was established by Nagao and Matsumoto (1940) on the basis of a single wellpreserved specimen, HK5960 (Figures 2-1 a, b,
c, 2a, b) from the Upper Cretaceous of Kamihobetsu, south central Hokkaido. Subsequently, Matsumoto and Noda (1968) separated I. yubarensis [ sic] from I. incertus as"Received September 20, 1989: revised manuscript
accepted May 15, 1990.
485

Masayllki Noda and Seiichi Toshimitsli

486

courtesy of T. Matsumoto. To make clear
the extent of variation and to settle the systematic position, a statistic method has been
applied for these specimens. Furthermore,
we discuss the phylogenetic relationshipbetween I. (P.) mantelli and allied species.

MethodTo make clear the extent of variation of I.
yubariensis [=1. (P.) mantelliJ from H.okkaido, a biometric method is applied forsome selected characters.
The basic linear measurements and angles
are shown in Figure I. A calipers of JIS
standard, 200 mm in measurable extent and 1/

20 mm in accuracy and a contact goniometer
were used for measurements of length andangle respectvely. A flexible guage was also
applied for shell convexity. The measurements were made three times for the same partand the mean was adopted. On the basis ofmeasurements, the mean value, standard deviation, population standard deviation andPearson's coefficient of variation of theselected characters were calculated.
The individual relative growth of shelllength vs. shell height and that of shell
breadth vs. shell height were examined.
These are demonstrated by reduced majoraxes on logarithmic graph paper and expressed by power functions [I =fJh a , b=fJhaJhb

Figure 1. Basic morphology for measurements. h: shell height, I : shell length, b: shell breadth, s :length of hinge line, H: maximum linear dimension from umbo to ventral extremity, L: Maximum linear
dimension perpendicular to H, GA: growth axis, a: anterior hinge angle, f3: beak angle, angle of umbonal
inflation, y: posterior hinge angle, 0: obliquity, angle between hinge line and H.

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Inoceramus (Platyceramus) mantelli

and the correlation coefficient is calculated
for each of them. Isometric or allometric
relationship is evaluated by means of the
K -test.
The ontogenetic change of I jh vs. H, thatof bjh vs. H and also that of obliquity (6') are
shown in the same way as Seitz's (1961) andTrager's (1967) for the comparison withall ied species.
For evaluation of the morphologicaldifferences between Mytiloides incertus and I.
(P.) yubariensis, and I. (P.) mantelli from
Europe and I. (P.) yubariensis, the Student's
t-test was adopted. If the F-value wassignificant, the t-value was calculated by the
Welch's method.
For the procedure of statistics, readers may
refer to Hayami (1969), Hayami and Matsukuma (1971), Tanabe (1973) and Noda
(1975).

Palaeon tological description
Family Inoceramidae Zittel, 1881
Genus Inoceramus Sowerby, 1814
Subgenus Platyceramus Seitz, 1961

Type species. -Inoceramus mantelli deMercey was designated by Seitz (1961).
Remarks. - Platyceramus was originallyproposed by Heinz (1932) as an independent
genus of Inoceramidae and he designated I.
mantelli de Mercey as the type species, but it
is invalid under the Code of r.C.Z.N., becauseof no generic diagnosis. Seitz (1961) gave
the diagnosis for Platyceramus as a subgenus
of Inoceramus (5.1.) and designated I.
mantelli as the type species. Since then,Platyceramus obtained the validity. Thus
the authorship of Platyceramus should be
ascribed to Seitz under the Art. 50 of r.C.Z.N.
For the subgeneric diagnosis and the additional notes, readers may refer to Seitz (1961)
and Noda (1979, 1983b, p.202). But Vokes(1967, 1980) has regarded Platyceramus as
being invalid, and Cox (1969) has included
Platyceramus to Inoceramus (5.5.) as a junior

487

synonym.

Inoceramus (Platyceramus) mantellide Mercey, 1877
Figures 2 - II

Inoceramus Mantelli de Mercey, p. 324, pis. I,

1877
2.

1878
1879

Inoceramus Mantelli, Barrois, p.478.
Inoceramus Mantelli, Barrois, p.454, pI. 4,
figs. I, 2.
1929 Inoceramus circularis SchlUter vaL oblonga
Heine, p. 54, 55.
1929 Inoceramus circularis SchlUter vaL undata
Heine, p. 55, 56, pI. 5, fig. 24.
1932 Inoceramus mantelli Mercey; Heinz, p. 10.
1934 Inoceramus mantelli Mercey (Barrois);
Heinz, p. 32.
1940 Inoceramus incertus limbo var. yubariensis
Nagao et Matsumoto, p. 11-13, pI. 5, fig. 1.
non 1954 Inoceramus mantelli de Mercey; Voute,
p. 149, 150, 153.
1962 Inoceramus (Platyceramus) mantelli mantelli
Mercey (Barrois); Seitz, p. 360-363, pI. 10, figs.
I, 2; pI. II, figs. I, 2, 6; pI. 12, fig. 3.
1962 Inoceramus (Platyceramus) manteIli undatus
Heine; Seitz, p. 363, 364, pI. 12, fig. 6.
1962 Inoceramus (Platyceramus) mantelli subrhenanus Seitz, p. 366, 367, pI. II, figs. 3, 4; pI.
12, fig. I.
1962 Inoceramus (Platyceramus) manteIli angusllIS Seitz, p. 367-369, pI. 12, figs. 2,5,7; pI. 13,
fig. I.
non 1962 Inoceramus (Platyceramus) manteIli (?)
rhenanus (Heinz; Seitz, p. 365, 366, pI. II, tig.
5. cf.) I. (Cordiceramus), n. sp. (in process ofstudy)
1965 Inoceramus (Platyceramus) manteIli beyenburgi Seitz, p. 96.
1968 Inoceramus yubarensis [sic] Nagao et Matsumoto; Matsumoto and Noda, p. 320.
non 1976 Inoceramus (Platyceramus) manteIli subrhenanus Seitz; Szasz, p.210, pI. 14. cf. I.
(P.), n. sp. A (in process of study)
1976 Inoceramus yubarensis [sic] Nagao et Matsumoto; Noda and Matsumoto, sheet 267, p. 1,
listed (in Japanese).
1977 Inoceramus waltersdorfensis yubariensis
Nagao et Matsumoto; Kauffman, p. 182, 183.
1983 Inoceramus (Platyceramus) yubarensis' [ sic]
Nagao et Matsumoto; Noda, p. 213, 214, textfigs. II, 12.
1985 Inoceramus man/eIli beyenburgi Seitz; Szasz, p. 171, pI. 33, fig. 3; pI. 34, fig. 2; pI. 40,
fig. I.

488

Masayuki Noda and Seiichi Toshimilsu

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Inoceramus (Platyceramus) mantelli

non 1986 Inoceramus (Plalyceramus) yubariensis
Nagao et Matsumoto (pars); Noda, p. 363, listed. I. (P.), n. sp. A (in process of study)
1986a Inoceramus (Plalyceramus) manlelli manlelli(Barrois); Lopez, p. 22-25, pI. I, figs. 3a, b.
1986a. Inoceramus (Plalyceramus) manlelli subrhenanus Seitz: Lopez, p. 25-27, pI. I, fig. 4.
non 1986a Inoceramus (Plalyceramus) manlelli ?
rhenanus Heinz; Lopez, p. 27, 28, pI. I, fig. 5.
1986b Inoceramus (Platyceramus) manlelli manlelli(Barrois); Lopez, p. 236, 237, pI. I, fig. 2.
1986b Inoceramus (Plalyceramus) manlelli subrhenanus Seitz; Lopez, p. 236, 237, pI. I, fig. 3.
non 1986b Inoceramus (Plalyceramus) manlelli ?
rhenanus Heinz, Lopez, p. 236, 237, pI. I, fig. 4.

Lectotype. - A specimen figured by Barrois(1879, pI. 4, fig. I = Seitz, 1962, pI. 10, fig. I)
was designated by Seitz (1962). For detailsof the designation of the lectotype, readers
may refer to Seitz (1962, p. 355 and 356).
Remarks. - The validity of the lectotype
designated by Seitz (1962) is somewhat questionable. The lectotype should be selectedfrom among the de Mercey's original specimens (1877) under the Code of Art. 74 of I.e.
Z.N., but Seitz designated the type specimen
from among the Barrois ones (1879). If
Barrois used the de Mercey's original specimens for his figures, it is reasonable, but Seitz
does not make any mention of this. Therefore, it is now outside of our capacity for tocomment on the validity of the lectotype.
Lopez (1986a) followed Seitz's designationand Szasz (1985) did not refer to thelectotype. We follow, at now, tentatively
after Sei tz.
Material.-In addition to the illustrated
specimens from abroad by literature, the following 32 specimens from Hokkaido areconcerned with this study, of which 25 specimens are used for measurements and statistics(BV: both valves, L: left valve, R: rightvalve). HK5960 (BV) (holotype of I. (P.)
yubariensis), loco H3019, coil. Otatume489(1932); GK.H8250 (R), loco RH2441; GK.
H8251 (R), loc. RH5047c8; GK.H8252 (BV),
loco RH4046p; GK.H8253 (BV), loc. RH
2148a; GK.H8254 (R), loc. RH2411d; GK.
H8255 (L), loc. RH1271a; GK.H8277A (L),loco RH7242b, coil. Uchida and Toshimitsu ;GK.H8277B (L), loco RH7242b, coil. Uchida
and Toshimitsu; GK.H8323 (L), loco
H3019; GK.H8324 (L), loc. Ik l117b, colI.
Matsumoto; G K.H8325 (R), loco R371
(RH 1275 of S.T.), coil. Nishida and Okada;GK.HIOI28 (R), loc. IA2119, colI. A. Inoma;
GK.H10129 (R), loc. IA2133, colI. A.
Inoma; JG.H2796 (R), loco Ik1506r, coil.
Matsumoto and Muramoto; JG.H2902 (R),loco Ik2707p; JG.H2906 (R), loco Ik 1535,
colI. Matsumoto and Muramoto; JG.H291O(R), loco Ik1533a, colI. Matsumoto and Muramoto; JG.H2917 (R), loco Ik1537, colI. Matsumoto and Muramoto; JG.H2918 (R), loc.
Ik2708, colI. Uchida; JG.H2912 (BV), loco
Ik5561p; JG.H2793 (L), loco IK56lp; JG.
H29I6 (L), loco Ik5617p; JG.H2921 (L), loc.
H2027c; JG.H2922 (R), loco H2027c; JG.
H2923 (R), loco Ik8387p; JG.H2924 (R), loc.
Ik8304p; JG.H2988 (R), loco Ik8053p; JG.
H3002 (BV), loc. Ik8390r; JG.H3003 (R),loco IK8390p; JG.H3004 (BV), loco Ik8060p
and JG.H3005 (R), loco Ik8064p.
The above specimens were mostly collectedby us, unless otherwise stated.
Repositories: GK: Dept. of Geology,
Kyushu University, Fukuoka, HK: Dept. ofGeology and Mineralogy, Hokkaido University, Sapporo, JG: Jonan Geological Association, Oita.
For localities, readers may refer to the
Appendix : Locality Guide.
Description.-Shell medium to large, equivalve, inequilateral, higher than long, withaxis of growth broadly concave towards theanterior. Valve gently and uniformly convex, anterior part steep to the commissure+- Figure 2. Inoceramus (Plalyceramus) manlelli de Mercey. l-a-c. HK5960, illustrated in Nagao
and Matsumoto (1940), from Loc. H3019. 2a, h. HK5960, same specimen, at present the umbonal part
missing. 3a, h. GK.H8277B, from Loc. RH724Ia. 4. GK.H8277A, from Loc. RH724Ia. (all figures innatural size)

Masayuki Noda and Seiichi Toshimilsu

490

Figure 3.

Inoceramus (Plalyceramus) manle//i de Mercey.

left va lve show ing anterior ear.

GK .H 8323, natura l size, from Loc. H30l 9.

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Inoceramus ( Platyceramus) manle/li

Figure 4. Inoceramus (Plalyceramus) manlelli de Mercey. GK.H8323 , sa me specimen of Figure 3.
na tural size Ie : ex tern a l m o uld of left va lve show in g the delicate o rn a men t of a nteri o r ea r.

49 1

492

Masayuki Noda and Seiichi Toshimitsu

plane and posterior one gradually flattened,passing into the wing-like area without sharpboundary. Anterior ear present and clearly
demarcated from the main part of shell.
Umbo terminal or subterminal and slightly
prominent. Anterior margin long, straightor slightly concave; ventral margin moderately rounded, passing gradually to broadly
arcuate and then nearly straight posterior one.
Hinge line about a half of shell length, withsome variability. Concentric ribs typicallylow, broad and weak but sometimes irregularin breadth and intensity. Minor rings generally fine and weak but occasionally somewhat
coarse and distinct.
Observation.-HK5960 (Figures 2-la, b, c;
2-2a, b) well shows the major ribs and minor
rings. Its umbonal portion is now missing.
It is articulated but the right valve is secondarily squashed. The cross section of theanterior ear is observed in the left valve.
GK.H8323 well preserves the anterior ear,
whose surface ornamentation is distinctly
impressed on the external mould (Figures 3,4a-c). GK.H8252 (Figures 5-la-e) andGK.H8253 (Figures 6-5a-c) are closed
articulated specimens. They show evidently
the original equivalveness, although areslightly dislocated along the plane of commissure. The hinge structure is clearly visible
and the anterior ear is preserved in GK.H8252(Figure 8-1), GK.H8277B (Figures 2-3a, b)
and JG.H2998 (Figure 6-1). The outer shelllayer is well preserved in JG.H2922 (Figure 6-8) and partially remains in JG.H2924 (Figure 5-2), GK.H8252, GK.H8253 and GK.
H10128, and the inner shell layer remains in
JG.H2910, JG.H2921 (Figure 6-7), JG.H2923(Figure 5-3) and GK.H8277B (Figures 2-3a,b). The concentric major ribs and minor
rings are well shown in HK5960, GK.H8252,
GK.H8253, JG.H 2921, 2922, 2923 and 2924.
In JG.H2923 the major ribs are comparatively
regular in strength near the umbo andbroaden gradually with growth, though very
irregular in JG.H2921, and the minor lirae arc
clearly visible in early stage of growth in both
specimens. Occasionally small pits of hemispheric pearl are impressed on the internalmould (JG.H2998, Figure 6- I).
Biometry. - The measurements of selectedcharacters, i.e., h, I, b, s, H, L, a, /3, y, 0,01l=6omm, Ijh, Ijh ll =6omm, LjH, LjH II =6omm
and sjl, are shown in Table 1. The statistics
for these characters are in Table 2. As isclear from Table 2, the Pearson's coefficient ofvariation are generally small for these characters, but for bjh ll =6o mm and sj!.
The individual relative growth of shelllength (I) vs. shell height (h) and shell
breadth (b) vs. shell height (h) in the twowell-preserved specimens are demonstrated in
Figure 9. The growth indices, Y -intercept of
the reduced major axes and the coefficient ofcorrelation for every specimen were calculated. According to Hayami and Matsukuma (1971, p. 150, 151), the reduced majoraxes in all the examined bivariate characters
are within the scope of negative monophasic
allometry. The ontogenetic changes of I jh,
bjh and shell obliquity (0) are demonstrated
in Figures lOA, Band C, respectively. As isclear from Figures lOA and B, the simple
ratio of I jh decreases gradually with growthin each individual, whereas the simple ratio
bjh is nearly constant throughout the growth.
The ontogenetic change of the angle (0)between hinge line and the growth axis
enlarges gradually with growth, as shown
Figure 1Oe. In other words, the obliquity
decreases with growth. The profiles of five
selected specimens in two directions are illustrated in Figure II.
Specific assignment
Seitz (1962, p. 355, 356) discussed the establishment of I. mantelli de Mercey (Barrois) in~
Figure S. Inoceramus (P!atyceramlls) man/elli de Mercey. la~e. GK.H8252, Loc. RH4046p. 2.
JG.H2924, Loc. Ik8304p. 3. JG.H2923, Loc. Ik8387, "lIndatus type" (Heine, 1929, p. 55; Seitz, 1962, p.
363) (all figures in natural size)

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Inoceramus (Platyceramus) mante//i

493

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Masayuki Noda and Seiichi Toshimitsu

detail. On the other hand, I. (s.l.) yubariensis was established by Nagao and Matsumoto(1940), originally as a variety of Inoceramus
incertus Jimbo (= Mytiloides incertus in arevised sense). Matsumoto and Noda (1968)
ranked it as an independent species for its
much taller outline and separated occurrence
in a higher stratigraphic position. In that
paper the original name of "yubariensis" waserroneously spelled as "yubarensis". Subsequently, Noda (1984) examined statistically a
number of specimens of M. incertus from "thetype locality (Ik20l1-2014), as representing a
fossil population. Accordingly the extent ofvariation of the measurable characters was
elucidated quantitatively. On this occasion,
we examine the morphological difference
between M. incertus and the so-called I. (P.)
yubariensis by means of the Student's t-test.
Before the t-test, the F -test was attempted.
The results are shown in Table 3. The
significant difference between the two species
is confirmed in the characters of a, y, and 1/
h, and the obliquity is nearly constant in M.
incertus throughout the growth (Noda, 1984,
p. 462, text-fig. 6A), whereas it decreases gradually in "I. (P.) yubariensis" (Figure 1OC).
From the above comparison, the two species
are clearly discriminated morphologically.
Matsumoto (1986, personal communication) has suggested us that I. (P.) yubariensis
may be specifically identical with I. (P.)
mantelli de Mercey. Evidently I. (P.)
yubariensis closely resembles I. (P.) mantelli
from the Coniacian of Europe, in many
respects, e. g., outline, ornamentation, modeof growth, hinge structure and existence ofanterior ear. According to Sornay (1981, p.
420), I. (P.) mantelli occurs in the Lower
Coniacian of northern France, partially associated with I. schloenbachi Fiege, andSornay (1983) cited the result of Amedro etal. (1979) that I. (P.) mantelli appears

already in the Upper Turonian of northern
France.
Seitz (1962) recorded the occurrence of I.
(P.) mantelli in the Lower and Middle
Coniacian of Germany, although the stage
and substage boundaries in Germany at thatdate (before Seibertz, 1979) were set at higher
level than those of the international scale.
Szasz and Ion (1984) defined the Middle
Coniacian of Rumania as the Assemblage
Zone of I. (P.) mantelli in parallel with theAmmonite Zone of Peroniceras tridorsatum(SchWter). Lopez (1986a, b) reported I. (P.)
mantelli from the Upper Coniacian of the St.
Corneri area of Spain.
Seitz (1962) divided the specimens of I.
(P.) mantelli obtained from the schaft 11 ofPreussen Mine and other areas of West Germany into five subspecies, e. g., I. (P.)
mantelli mantelli Mercey (Barrois), I. (P.)
mantelli undatus Heine, I. (P.) mantelli (?)
rhenanus Heinz, I. (P.) mantelli subrhenanus Seitz and I. (P.) mantelli angustus
Seitz [= I. circularis SchWter var. oblonga
Heine, 1929, =1. (P.) mantelli beyenburgi
Seitz, 1965]. Szasz (1976, 1985) and Lopez(1986a, b) followed Seitz's subspecific distinction. However, it is biologically unnaturalthat various subspecies of one species occur inthe synchronous stratigraphic unit of a limited area, unless their habitats were originallydifferent.
On the other hand, Sornay (1986, in a letter
to Matsumoto) pointed out some questions
about Seitz's assignment of the specimens ofA408, the holotype of I. (P.) mantelli (?)
rhenanus Heinz (Seitz, 1962, pI. 2, fig. 5) andthe specimen of I. (P.) mantelli subrhenanus
Seitz (Szasz, 1976, pI. 14) to the species I. (P.)
mantelli. We agree with his suggestion.
The specimen of A408 is probably discriminated at specific level from I. (P.)
mantelli because of its acutely pointed beak,~ Figure 6. Inoceramus (Platyceramus) mantelli de Mercey.
1. JG.H2998, natural size, Lac. Ik8053,
showing anterior ear. 2. JG.H2976, X 1.3, Lac. Ik1506r. 3. GK.H8255, natural size, Lac. RH1271a. 4.
JG.H2907, X 1.4, Lac. Ik1536. Sa-c. GK.H8253, natural size, Lac. RH2148a2. 6. GK.H8254, naturalsize, Lac. RH2411d. 7. JG.H2921, X 1.3, Lac. H2027. 8. JG.H2922, natural size, Lac. 2027.

900 .

In oceramus ( Platyceramus ) manlelli

495

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Masayuki Noda and Seiichi Toshimi/su

small beak angle and a ng ul a rl y benl co ncen tric undulation. The Szasz' s specim en fro m
the Vas il atu Formati o n o f th e Brezo i Bas in(South Carpathian area , Rumania) is a lso
discriminated from the typi ca l form of I. (P.)
mante//i subrhenanus Se itz, so far as we
observed hi s ph o togra ph , in its sma ll bea kangle a nd the o ntoge netic change of o bliquity. Similar specimens to Szasz's occ ur in
the Upper Coniacian of Hokk a id o; thesewill be described in a se pa rate pa per by o neof the a uthors (M. N.) . The ident ificati o n o f
the spec ime n N°- 35009 of L6pez (1986a , pI. I,
fig. 5; 198 6b, pI. I,fig. 4) w ith 1. (P.) mantelIi (s.l.) is a lso doubtful , beca use of its sma llbeak a ngle , considerably infl a ted shel l anda lmo st invariable obliquity throughout thegrowth.
Alth o ugh the subspecific discrimination by
Seitz (1962) is unre aso na bl e under the mo dern bi o log ica l concept, it suggested a large
extent of variation in a species of I. (P .)man/elli in its outline a nd surface o rn amenta-tion i.e. , intens ity, breadth and c ur vat ure.
At the suggestion of Sorn ay (1986 , personalco mmunica ti o n thro ugh Ma tsum o to ), th emeas urem e nts o n th e photograp hs of seve ra l
spec im ens of 1. (P.) mantelli by Se itz (1962)
are show n in T a bl es 4 a nd 5. To m a ke clear
the mo rph o lo g ica l differe nce between the twoforms from J apa n a nd Europe, F -test a nd
I-test ha ve bee n applied for so me se lectedc ha racters. The I-va lues, as show n in T a bl e
6, are not signifi ca nt about a ll the exa min ed
c ha racters except for the simpl e rati o sj l.
I. (P .) manlelli is a lso reco rd ed in th eUpper Coniacian (in the bipertite sc heme o f
the USSR) of th e platfo rm o f East Europe,
Ca ucas us and th e western reg io n of Cen tra l
Asia (Mo skvin el al. ed ., 1986 , p. 201 , 282;
19 87, p.17 5). Although th e Upper
Co ni ac ia n bip a rtite in th e Ru ss ia n sc he me
may overl ap with the upper part of the
Middle Co ni ac ia n of the inte rn a ti o n a l
sc heme, the ra nge of J . (P .) mante!!i in
Europe and contiguous regions is partially

Figure 7. Inoceramus (Plalyceram us ) manlelli de Mercey.
RH 1275). 2. G K.H 8324, n atu ra l size, Loc. Ik 111 7b

1. GK.H 8325, natural size, Loc. R 37 1 ( =900.

Inoceramus (Pfatyceramus) manle1!i497

Figure 8. Ligament structure 1. In oceramus (Plalyceramus) mal1lelli de Mercey. GK.H8252 2.
In oceramus (Platyceramus) cr. rhomboides Seitz. JG.H2899 , Loc. Kt6 , Onkono-sawa (Sanada co Il. , 1980).
3. Inoceramus (Inoceramus) cuvierii Sowerby. JG .H2983, Loc. H 2065p, Nutapomanai , H obets u, a rea ,internal mould . 4. Ino ceramus (s. I.) amakusensis Nagao et Matsumoto. JG .H29 84, Loc. HI102 , Hinoshima , Amakusa , Kyu shu , interna l mould .

overlaps that of I . (P.) yubariensis in Hokkaido. In fact , the former occurs throughout
the Coniacian Stage, with some del ay eastwards, whereas the latter occurs in the Upper
Coniacian and Santonian.
To sum up, the morphol ogica l difference
between the sam ples of I . (P.) y ubariensis
from Japan and that of I. (P.) mante1!i from
Europe is so slight that they are certainly ofidentical species; the former falls in a junior
sy nonym of the latter.

Comparison
I. (P.) expansus Baily, 1855 (p. 462 , pI. 13,
fig. 5) from the probable Santonian of South

Africa , has a broad a nterior ear, but differsfrom I. (P.) mantelli in its large ratio of I j h ,Lj H and the large anterior hinge angle.
I. (P.) cye/oides ahsenensis Seitz, 1961
from the Santonian of the Rhur area , West
Germany , somewhat resembles I . (P.)
manle1!i in its tal l outline with gentle convexity and the ontogenetic change of obliquity,
but the former is discriminated from the latterin it s considerably convex anterior margin ,narrowly arc uate ventral margin , predominant and regular conce ntric ribs a nd abse nceof an terior ear.
I . (P.) co//ignoni Sornay, 1964, from theConiacian of M ad agascar is also simi la r to I .
(P .) manle1!i subrhenanus Seitz, 1962 an d I .

Masayuki Noda and Seiichi Toshimitsu

498

Table 1.
specimen

valve

h

b

HK 5960

L.

92.0

70.0

19.0

Jc. H 2793
Jc. H 2796
Je. H 2902
Jc. H 2906
Jc. H 2910
Jc. H 2912
Jc. H 2916

R.

109.3

89.0

22.1

R.

48.6

40.5

9.6

R.

60.4

50.4

R.

37.6

29.6

R.

48.0

40.6

R.

60.5

58.6

L.

56.7

JC.H 2917

R.

JG. H
JG. H
Jc. H
JG. H

2918

H

L

a

B H=60mm

l/h

95.0

72.0

107"

123"

70"

0.76

113.2

89.0

112"

113

0

75"

0.81

19.0

50.4

43.6

117"

110"

68"

0.83

12.4

22.9

68.7

58.0

100"

126"

63"

0.83

7.8

16.2

39.7

31.8

96"

Ill"

H

0.76

21.0

50.5

44.9

III"

128"

6T

0.85

13.0

26.7

62.0

54.8

109"

116

0

60"

0.97

47.4

16.5

23.0

65.8

50.3

108"

130"

60"

0.84

50.0

39.0

9.9

22.0

54.8

46.7

97"

126"

63"

0.78

R.

61.0

55.2

12.0

23.0

68.2

53.4

97"

125"

H

0.90

2921

L.

33.1

30.6

5.5

16.4

38.2

26.5

91"

127"

56"

0.92

2922

R.

42.9

123"

47"

1.01

44.8

40.0

Measurements of Inoceramus (P!alyceramus)

45.3

6.4

16.4

56.2

2923

R.

90.6

70.0

19.0

39.2

93.0

71.0

113"

7T

56"

Jc. H 2998

R.

65.1

66.3

14.0

30.2

73.7

60.2

143"

54"

50"

1.02

JG. H 3002

L.

86.6

83.0

12.3

37.0

94.0

82.7

122"

64"

57"

0.96

R.

77.6

70.0

13.4

41.7

77.6

75.2

128"

60"

53"

0.90

0.77

JG. H 3003
JG. H 3004
JG. H 3005

R.

41.5

44.7

8.5

19.8

46.9

41.6

L.

88.8

89.6

13.0

28.1

98.3

80.8

140"

57"

53"

1.01

R.

94.5

94.5

18.6

45.5

101.0

97.7

139"

63"

58"

1.00

GK. H 8250

R.

47.6

40.4

11.0

21.7

54.3

45.8

64"

0.85
0.85

GK. H 8251
GK. H

8252

GK. H 10128

R.
L.

44.3

37.7

56.7

50.0

R.

65.2

L.

26.5

GK. H 10130

L.

GK. H 10131
GK.H

57.0

50.0

L.

30.0

28.0

L.

108.6

91.8

1.08

9.3

20.3

48.5

39.0

127"

65"

9.3

27.2

64.6

53.0

III"

66"

65"

65"

62"

15.4
21.4

59"

6.5

72.3
12.3

29.6
64.0

23.1

115"

52"

43.0

135"

58"

14.0

23.0
16.0

34.0

28.0

128"

60"

20.0

57.0

112.6

96.0

120"

64"

0.88
0.81

57"

0.88
0.93

56"

0.85

reference:
BH=6omm: angle between hinge line and H at the growth stage of 60 mm in H, l/h: simple ratio of
I vs. h, l/h H=6omm: simple ratio of I vs. h at the growth stage of 60 mm in H, b/h: simple ratioof b vs. h, b/h H=6omm: simple ratio of b vs. h at the growth stage of 60 mm in H, L/H: simple ratio(P.) mantelli beyenburgi Seitz, 1965 [= I.
(P.) mantelli angustus Seitz, 1962J as Sornay(1964) already pointed out. But it differsfrom the two subspecies in its more inflatedshell, weak major concentric ornamentation,
absence of anterior ear and almost constantobliquity throughout the growth.
I. (P.) cycloides colossus Sornay, 1969 fromthe Lower Campanian of tripartite scheme ofMadagascar may be analogous to I. (P.)

mantelli in its tall outline, but the former isclearly distinct from the latter in its convex
antero-dorsal margin, regular concentric
ornament and their curvature, which is narrowly bent at the ventral extremity, and thealmost invariable obliquity throughout thegrowth.
I. (P.) paramantelli Sornay, 1969 from theUpper Santonian of tripartite scheme to theLower Campanian of Madagascar is clearly

900.
manlelli from Hokkaido.

Inoceramus (Platyceramus) manlelli499

linear dimension in mm.

Ijhfl~6omm

bjh

bjh H =6omm

LjH

LjH"=6omm

sjl

0.98

0.21

0.21

0.76

0.84

0.57

anterior wing

0.20

0.20

0.79

0.97
0.47

smaller than 60 mm in H

0.96

0.20
0.83

0.21

0.87
0.20

0.20

0.84

0.84

0.80

remarks

hinge part imperfect
0.45
0.59

smaller than 60 mm in H

0.52

somewhat crushed

0.97

0.21

0.21

0.88

0.88

0.46

anterior wing

0.85

0.29

0.29

0.76

0.77

0.49

0.89

0.20
0.90

0.20

0.86
0.20

0.56

0.78

0.80

0.42

0.17

0.69

0.53

smaller than 60 mm in H

0.14

0.76

0.36

smaller than 60 mm in H

0.82

0.21

0.20

0.76

0.78

0.56

1.09

0.22

0.21

0.82

0.83

0.46

1.02

0.14

0.17

0.88

0.90

0.45

1.02

0.17

0.18

0.97

1.00

0.60

0.20

0.89

0.44

1.03

0.15

0.15

0.82

0.81

1.01

0.20

0.22

0.97

0.80

0.88

smaller than 60 mm in H
hinge part imperfect

0.48

0.23

0.84

0.54

smaller than 60 mm in H

0.21

0.80

0.54

smaller than 60 mm in H

0.16

0.17

0.82

0.82

0.55

0.24

imperfect, anterior wing

0.25

0.78

0.25
0.96

smaller than 60 mm in H

0.18

0.26

0.57

smaller than 60 mm in H

0.67

0.46

smaller than 60 mm in H

0.82

0.57

somewhat cruthed

0.62

anterior wing

0.85

0.76

of L vs. H, LjH fI =6omm: simple ratio of L vs. H at the growti stage of 60 mm in H, sjl: simple
ratio of s vs. I, L.: left valve, R.: right valve.
F or others readers may refer to Figure I.

distinguished from /. (P.) mantelli, regardlessof the derivation of the specific name, in its
long outline, comparatively short anterodorsal margin, large ratio of sll and considerably
oblique growth axis, though the developmentof the anterior ear in the specimen no. 161 I(Sornay, 1969, pI. F, fig. 5) is similar to that of
the specimen GK.H8323 (Figure 4-c).
/. (P.) miyahisai Noda (l983a, p. 103, III,
112, pis. 2, 5) from the Middle Campanian ofwestern Shikoku also resembles I. (P.) manlelli in its tall outline with gentle convexity
but differs in its convex anterior margin,
predominant major ribs and the absence of
the anterior ear. Its stratigraphic position is
also much higher than that of I. (P.) mantelli.

Discussion of phylogeny"Inoceramus (Platyceramus) yubariensis"

Masayuki Noda and Seiichi Toshimitsu

500
Ib
90
80
70

1= 1.950ho. 768

A

HK5960I/hr = 0.9928

A

JG.H2902

I. os

JG.H2917

60
50

B

40

1= l.260ho. 896

1.00

r= 0.9978

0.95

30

JG.H1923

0.90
0.85

20
/

/

.

1()

0.80

/

/

/

10

/

20

30

/

AD

50

60

70

80

90

100

H

/

",0

9

//

8

7

/

/

/
b/h

B

0.35

A

b=0·330hr = 0.9927

0.873
0.30
0.25

B

b =0. 420ho. 640

0.20

I

B ~--

--0

.

<(..>~~?'':!,,>,~ "c~c~-"""'--<>

r=0·9988

i\ ----.... JG.H2917R
!

.

10

20

30

40

50

60

70

80

90

100

H

10

20

30

40

50

60

70

80

90

100

H

JG.H 2923R

Lr-,.....-r'--.-r'--'-,--,------,--,--T---r-r~
70910
10
30
40 5060706090
h

6

70

Figure 9. Diagram showing the individual relative growth between I vs. hand b vs. h (in mm) for
selected specimens of Inoceramus (Platyceramus)
mantelli .

65
60
55

was originally assigned to a variety of
Mytiloides incertus (Jimbo, 1894) from theUpper Turonian. The two species of I. (P.)
yubariensis [= I. (P.) mantelliJ and M. incertus are apparently similar to each other ina gently and uniformly convex shell and inconspicuous concentric ribs with distinct
minor rings. Matsumoto and Noda (I968)
tentatively assigned M. teraokai (Matsumoto
et Noda, 1968) to Platyceramus, but this has
been corrected since Matsumoto et al. (1982,p.64). M. teraokai indeed resembles Platyceramus in outline and surface ornamentation. Particularly, the existence of an anterior ear in M. teraokai and I. (P.) mantel/ai
suggests close phylogenetic relationship.
M. incertus, a senior synonym of M. fiegei
fiegei (Trager, 1967) (see Noda, 1984), is

Figure 10. Diagram showing the ontogenetic
change of selected characters. A: simple ratio I/h,
B: simple ratio b/h, C: obliquity.

common in the Upper Turonian of various
regions of the world. Its stratigraphic position is generally lower than I. (P.) mantel/i.
In our opinion, the resemblance between M.
incertus and "/. (P.) yubariensis" in Japan iswell harmonious with that between "M.
fiegei fiegei" and I. (P.) mantelli in Europe.
However, the value of Ilh in I. (P.) mantelli
becomes smaller with growth. In otherwords, the outline becomes gradually higher,
whereas the value of Ilh in M. incertus isalmost constance throughout the growth.
Moreover, the hinge structure is clearly dis-

900.
Table 2.
aInoceramus (Platyceramus) mantelli

SOlBiometric characters of Inoceramus (Plal),ceramus) manlelli from Hokkaido.
I

OH~6omm

I/hll~6omm

b/hll~6omm

L/HII~6omm

sll

N

27

24

16

14

14

14

24

m

105.2

124.1

57.2

0.951

0.205

0.843

0.511

s

9.46

9.36

3.67

0.08300.03590.07180.06570.0644
12.86

15

9.28

9.17

3.56

O.OSOO

0.0346

0.0692

v

8.99

7.54

6.42

8.73

17.51

8.52

reference:
N: sample size, 111: mean value,s: standard deviation, (j: population standard deviation,
v: Pearson's coefficient of variation.

tinct between Platyceramus and Mytiloides,that is, the ligament pits of M. labiatus are
finer and smaller than those of Platyceramlls,
as illustrated by Sornay (\966, p. 63, fig. 26),
and those of M. teraokai are also of
Mytiloides type (Matsumoto and Noda, 1968,
p. 322, text-fig. 2). The difference of the ligament structure should be regarded as a taxonomic criterion above the specific level.
From the above discussion, it is questionable
to link Platyceramus to Mytiloides.
Kauffman (1977) regarded "I. (P.) Yllbariensis" as a subspecies of I. waltersdOifensis
Andert, 1911 from the highest Turonian to
the Lower Coniacian of the Euramerican and
Caribbean regions, and pointed out" I. (P.)
yubariensis" is possibly descended from I.
waltersdolfensis. Troger (1967, p. 118, 119)clearly described subspecific distinction
between I. waltersdOifensis waltersdOifensis
Andert and I. waltersdOifensis hannorrensis
Heinz, 1932, saying that two subspecies are
hardly discriminated in the juvenile stage, butthat the shell convexity increases gradually inthe former and the concentric rings arebroadened with growth in the latter. As
shown in Figure II, the shell convexity of I.
(P.) mantelli from Hokkaido is comparablewith that of I. waltersdOifensis hannorrensis
illustrated by Troger (\967, p. 120, fig.31).
In fact, I. waltersdOifensis hannovrensis resembles roughly I. (P.) mantelli from Hokkaido in outline, shell convexity and surface
ornamentation, but more presice examinationof ligament structure, presence or absence ofanterior ear and ontogenetic change of form
ratios on a number of well preserved specimens, is necessary to make clear thephylogenetic relationship between the two
species.
Kauffman (1977) also mentioned that "I.
(P.) Yllbariensis" may be incorporated in an
early form of I. ( Cremnoceramlls) inconstans
Woods (1911, also see Andert, 1934, pI. 3, fig.
I). The specimen (A. Nr. 35) of I. (Cr.)
inconstans Woods em. Andert from theUppermost Turonian (in the Scheme of
Seibertz, 1979) resembles the "holotype of I.
(P.) yubariensis" (HK5960, this paper, Figures 2-1 a, b, c; 2-2a, b) in general outline
and surface ornamentation, but the specimen
HK5960 is characterized by the existence ofanterior ear (the section of anterior ear isvisible in Figures 2-lb, c). In our opinion, it
is still insufficient to link phylogenetically
Platyceramlls to Crel11noceramus.
To sum up, the ancestry of I. (P.) l11antelli
is as yet uncertain.
On the other hand, I. (P.) l11antelli may be
the common or ultimate ancestor of various
species of I. (Platyceramlls) from theSantonian and Campanian Stages. In connection with the restudy of the so-called I.
japonicus Nagao et Matsumoto, 1940, N oda(1983b) showed an idea of parallel development of I. (P.) ezoensis Yokoyama, 1890 and
I. (P.) mantelli [I. (P.) yubariensis at thatdate] from some common ancestor, giving

Masayuki Noda and Seiichi Toshimitsu

502-----------I------~ GK. H825 2
6-----------.
---U

.J

V

L_~_.___R~

Figure 11.

JG .H2922

Profiles of five selected specimens in two directions.

rise to I. (P.) japonicus and I. (P.) higoensis
Noda, 1983 respectively in later stages of
evolution. Besides a clearer redescription of
I. (P.) ezoensis is necessary, as Matsumoto etal. (1982) pointed out. Recently Matsumotopresented a question in our free discussion
what species was rised from I. (P.) mantelliin Europe, if the species I. (P.) higoensis wasderived from that species in Japan.

I. (P.) higoensis was originally included in
the scope of I. japonicus Nagao et Matsumoto, 1940 as forma a, for its characteristic
ornamentation with divergent ribs superposedon the concentric sculpture, but it is discriminated from the typical form (y) andanother one (/3) in its tall outline, short hingeline and the ontogenetic change of obliquity
as shown in N oda (1983, p. 213, text-fig. II).

900.
Table 3.

A

Inoceramus (Platyceral11us) mantelli

503

F-test and Student's I-test of the selected characters of Inoceramus (Plalyceramus)
manlelli [=1. (P.) yubariensis] and Myliloides incerlus (limbo)
l/hH~6omm

L/HH~6omm

a

r

N

27

24

14

14

24

m
s

105.2

124.1

0.951

0.843

0.511

9.46

9.36

0.08300.07180.0657sll

F value

2.11164.1403

1.46611.2652

1.0369significance

•

•

0

0

0

I value

2.806

4.678

2.473

0.361

0.672

significance

•

•

•

0

0

N

30

17

15

30

23

m
s

113.3

147.0

1.036

0.860

0.498

6.51

4.60

0.10050.08080.0669B

reference:
A: Inoceramus (Plalyceramus) manlelli [=Inoceramus (P.) yubariensis], B: Myliloides

incerlUs,• : significant, 0 : not signficant.
For others readers may refer to Tables 1 and 2.

Table 4.
specimens

Measurements of Inoceramus (Platyceramus) manlelli from West Germany. linear dimension in mm.

valve

h

I

s

H

L

a

r

OJl=60mm

I/h

Ijh H=6omm

L/H

L/H H =6ornm

5/1

70

52

liT

143

45

42'

1.23

1.26

0.74

0.71

0.53
0.58

"

lectotype

R.

52

64

34

paratype

L.

81

96

56

110

79

Ill'

131

56

50'

1.19

1.43

0.72

0.75

B667

R.

134

128

76

140

137

140'

112'

76'

62'

0.96

1.22

0.98

1.00

0.59

B668

R.

317

249

152

368

235

90'

132'

57

40'

0.79

0.84

0.64

0.72

0.61

B6106

R.

97

80

31

97

78

liD'

120'

71

64'

O.S2

0.79

0.80

0.72

0.39

Ko473

L.

84

78

50

101

78

102'

liS'

58

48'

0.93

1.17

0.77

0.90

0.64
0.64

Ko478

L.

136

106

68

144

114

110'

114'

70'

50'

0.78

0.82

0.79

0.92

S291WB

L.

141

112

51

144

108

110'

III

74

58'

0.79

1.10

0.75

0.90

0.46

S294WB

R.

80

70

40

90

72

100'

113'

60'

56'

0.88

0.85

0.80

0.75

0.57

S296WB

L.

67

57

37

77

63

120'

136'

70'

6Y

0.85

0.78

0.82

0.77

0.65

S297WB

R.

82

79

46

94

77

100'

130'

60'

53'

0.96

1.00

0.82

0.76

0.58

S337WB

L.

212

192

100

244

196

123'

128'

65

54'

0.91

1.00

0.80

0.84

0.52

In that paper, Noda referred briefly to thestock of I. (P.) undulatoplicatus Roemer
connecting with I. (P.) rhomboides Seitz,
1961 and I. (P.) cycloides Wegner, 1905.
Sei tz (1961) descri bed three su bspecies in I.
(P.) llndulatoplicatus [I. (Cladoceral11us)
undulatoplicatus in Seitz's sense] e.g., I. (P.)
undlilatoplicatlis undulatoplicatlls, I. (P.)
llndlilatoplicatus michaeli Heinz, 1928 and I.
(P.) llndlilatoplicatus subsp. indet., of which
the specimens of subspecies indet., i.e., Ko.

135, S335WB and Hg, 49, are indeed similar
to I. (P.) mantelli in their concave anterior
margin, large anterior hinge angle (a), shorthinge line and the ontogenetic change ofobliquity except for development of divergent
plicae, and the stratigraphic position of thesubspecies is somewhat higher than that of I.
(P.) l11antelli.
Furthermore, the specimen no. 685 of I.
(P.) aff. llndulatoplicatlls michaeli Heinz(Sornay, 1964, p. 175, fig. 7) from the Middle

Masayuki Noda and Seiichi Toshimitsll

504

Table 5.

Biometric characters of Inoceramus (Platyceramus) manlelli from West
Germany.

ayall~60mml/hll~6omm

N

12

12

12

12

12

m
s

111.6

123.8

53.5

1.022

0.812

0.563

13.15

10.87

8.04

0.2147

0.09670.0777

(J

12.59

10.41

7.70

0.2056

0.09250.0744

v

11.78

8.78

15.03

21.01

11.91

13.80

Table 6.

L/HII~6omm

sll
12

F-test and Student's I-test of the selected characters of Inoceramus (P.) manlelli from
Hokkaido and West Germany.
L/HH~6omm

all~60mm

I/hH~6omm

24

16

14

14

24

124.1

57.2

0.915

0.843

0.511

9.36

3.67

0.08300.07180.06571.9323

1.34874.79946.69131.81381.3987significance

0

0

•

•

0

0

( val ue

1.725

0.086

1.483

1.077

0.937

2.107

significance

0

0

0

0

0

•

N

12

12

12

12

12

m
s

111.6

123.8

53.5

1.022

0.812

0.563

13.15

10.87

8.04

0.2147

0.09670.0777

A

B

a

y

27
105.2
9.46

F value

N
m
s

sll

12

reference:
A: sample from Hokkaido, B: sample from West Germany, • : significant, 0 : not significant.
For others readers may refer to Tables 1 and 2.

Santonian of the Ampamba-Antsirasiraregion of Madagascar also resembles I. (P.)
mantelli in the characters mentioned above.
These facts may suggest some phylogenetic
relationship between the two species.

Conclusion
1. From the results of biometric examination, Inoceramus (Platyceramus) mantelli deMercey, 1877 from Japan, including theholotype and topotype of I. (P.) yubariensis
Nagao et Matsumoto, 1940, shows a small
extent of variation in the examined characters,
i. e., a, y, 0, Ilh and L/H.
2. The individual relative growth of shelllength vs. shell height and that of shell
breadth vs. shell height show negative allometry. The simple ratio of llh and shell
obliquity decrease gradually with growth,
while simple ratio blh is relatively constantthroughout the growth or slightly decreases.
3. The morphological differences between
the form of I. (P.) mantelli from Japan andthat of I. (P.) mantelli from Europe andeastern contiguous regions is so slight thatthey can be regarded as specifically identical.
Stratigraphically the former ranges from theUpper Coniacian upwards to the Santonian
and the latter throughout the Coniacian.
Although there is some delay in the occurrence of the Japanese form, I. (P.) yubariensis

900.

Inoceramus (Platyceramus) mantelli

Nagao et Matsumoto, 1940 is evidently ajunior synonym of I. (P.) mantelli de Mercey,
1877.
4. The ancestry of I. (P.) mantelli is
uncertain. Mytiloides incertus (limbo) fromthe Upper Turonian of Japan, Europe andelsewhere looks somewhat similar to I. (P.)
mantelli, but the true phylogenetic relationship between Inoceramus (Platyceramus) andMytiloides or Cremnoceramus has yet to beworked out by examining the fundamental
characters, e.g., hinge and shell structures.
5. I. (P.) mantelli may be a common or
ultimate ancestor of various species of Inoceramus (Platyceramus) from the Santonian
and Campanian.

505

APPENDIX: Locality guide
Arranged in the order from A to D in the index
map of Figure 12.
Loc. H3019. The type locality of Inoceramus(Platyceramus) yubariensis Nagao et Matsumoto,

Acknowledgements
We express our sincere thanks to Emeritus
Professor Tatsuro Matsumoto of Kyushu
University for his help in the field and laboratory works, instructive suggestion and criticalreading of the typescript. We wish to thankDr. Jacques Sornay of France for his courtesy
to give us valuable comments on I. (P.)
mantelli de Mercey through a letter (1986) toMatsumoto. We are also indebted to Professor Makoto Kato and Ex-professor Toshimasa Tanai of Hokkaido University for theirkindness to let us study freely certain typespecimens of Nagao and Matsumoto (1940)
and allow us to refer to the locality map in
unpublished manuscript of a thesis by
Otatume (1933). We are grateful to Mr.
Yasuo Ohtsuka for reading the typescript.
We wish to thank the late Mr. Tatsuo Muramoto and Messrs. Yoshitaro Kawashita,
Takemi Takahashi and Jinkichi Mitsunushi
of Mikasa, Mrs. Kikue Kato, Mr. Shigehiro
Uchida of Iwamizawa and Mr. Hitoshi Kikuchi of Otaru for their help in the field workand supply of some useful specimens. A partof the financial expenditure was defrayedfrom the Ministry of Education, Science andCulture to Noda (1984, No. 59916035) and to
S. Toshimitsu (1988, No. 63790265).

MAP

lookm

HOBETS AREA

Kamihobets

o

lOOOm

t=;;;;===~J

Figure 12. Above: Index map of Hokkaido,
showing the studied areas, A: Hobetsu area, B:
Ikushumbets area, C: Kotanbetsu area, D: Haboro
area. Below: Locality map of Kamihobetsu.

Masayuki Noda and Seiichi Toshimitsu

506

1940. Topographic map of the Osawa Quad. (I:25000), Long. 142°12'30"E, Lat. 42°55'44"N. A cliff
on the left bank of the main course of the R. Hobetsu,
Kamihobetsu (Osawa), Hobetsu area, southern central
Hokkaido (Figures 12, 13). Zone of Inoceramus(s.l.) amakusensis, upper part of the Upper Yezo
Group, Santonian.
Loc. H2027c. Topographic map ditto, Long. 142°12'12"E, Lat. 42°55'20"N. A cliff on the right bank of
the main course of R. Hobetsu, about 750 m downstream from loc. H3019, probably same horizon as theloc. H3019 (Figure 12).
Locs. Ik1506r, 1533a and 1535. Topographic mapof the Katsurazawa-ko Quad. (I : 2S000), Long. 142°
3"04"E-142°03'07"E, Lat. 43° 13' 10"N _43° 13'06"N.
The road cutting along the R. Ikushumbets, Ikushumbets area, central Hokkaido. Lower part of theMember lIId, Zone of I. (s.l.) amakusensis,
Santonian (Figure 14).
Loc. Ik1537. Topographic map ditto, Long. 142°3'
32"E, Lat. 43°12'42"N. A cliff on the left bank of theR.Ikushumbets, about 500 m downstream from theconfluence of the Hidarimata-zawa. Upper part of
the Member IIIc, Zone of I. (Cremnoceramus) millOensis. Upper Coniacian.
Locs. Ik5561p and 5617p. Topographic map ditto,
Long. 142°04'02"E-142°04'06"E, Lat. 43° 12'2S"N-43°
12'31"N. Pebbles in the Hidarimata-zawa, a tributary of the R. Ikushumbets, in the sequence of theZone of I. (Cr.) mihoensis and Zone of I. (s.l.)amakusensis, stratigraphic position precisely unknown (Figure 14).
Loc. Ik8304p. Topographic map ditto, Long. 142°
06' 36"E, Lat. 43° II '28"N. A pebble on the forestry
roadside along the Okuhidarimata-zawa, a tributaryof the R. Ikushumbets, probably originated from theMember IIIc. Upper part of the Middle Coniacian- - - - - - - H3020(Figure 14).
Locs. Ik8387p and 8390r. Topographic map ditto,
Long. 142'OS'S7"E, Lat. 43° 10' 16"N-43° 10' 14"N.
Pebbles in the upper reaches near the terminal of theforestry road along the Yubarigoe-zawa, a tributary of
the Okuhidarimata-zawa. Stratigraphic position
exactly unknown (Figure 14).
Locs. Ik8053p and 806Op. Topographic map ditto,
Long. 142°00'S6"E-142°01'I2"E, Lat. 43°11'24"N43° 11'30"N. Pebbles in the Hiromine-zawa, a tributary of the Kikumezawa, Ikushumbets area, probably
in the sequence of the Member HIc of the Upper Yezo
Group (Figure 14).
Loc. Ik8064. Topographic map ditto, Long. 142°00'
47"E, Lat. 43°11'24"N. A stream floor of the
Hiromine-zawa, about ISO m upstream from theconfluence with a little branch. Stratigraphic position: IIIc or IIId, exactly unknown (Figure 14).
Loc. Ik1117b. Topographic map of the Mikasa
Quad. (I: 2S000), Long. 141°S9'S2"E, Lat. 43°13'06"
N. A cliff on the right slope of the Banno-sawa, atributary of the R. Ikushumbets, above the key bed oftuffaceous sandstone, basal part of the Zone of I. (s.l.)amakusensis (see Matsumoto, 1965, fig. 2. for thelocation; now under the water of the artificial lake of
Katsura-zawa dam) (Figure 14).
Locs. Ik2707 and 2708. Topographic map of Ikushumbets Quad. (I : 2S000), Long. 141°59'22"E, Lat.
43°17'S2"N. A cliff on the left bank of the upper
reaches of the Pombetsgono-sawa (= Takino-sawa or
Takiyoshi-zawa), a tributary of the R. Pombets, Ikushumbets area, upper part of the'Member HIe of theUpper Yezo Group. The stratigraphic position of
Loc. Ik2707 is about 3 m above of Ik2708. Upper
Coniacian. For details readers may refer to Matsumoto and Noda (l98S, p.265, text-fig. I). For the
stratigraphic succession in the Ikushumbets area

- - - - - - - + 0 - - - - - - - - - H3019 - - - - - - - - - -Figure 13. Sketch of the outcrop H3019 (in July 1988) (type locality of I. yubariensis). A: Inoceramus (s.l.) amakusensis, m. Inoceramus (Platyceramus) mantelli, n: Sphenoceramus naumanni, .: insitu, + : fallen, a: 0.7m, b: 2.0m c: 2.7m

IKUSHUMBETS AREA

43°13'

~

o

?
g
;:s
~

:::!

:::

to,

i¥

a-.l'!a~o·'<>.'~*-o-'~-

~

~

;:s
:::!

-:::!t:;
I:)
~

ii;

-.

43°11':::::

Ik8387p,
I k8390p:',.
.... ~,.

o!

142°2'

2000m,
142°4'

142°6'
V>

Figure 14.

Locality map of the Ikushumbets area.

o-.IMasayuki Noda and Seiichi Toshimitsu

508

o
,
14200

59'

KOTANBETS AREA

IA2119 .~
~

Cl)

o

. ~ IA2133

~
~'

1000m

1;;;;;;;;0====""

E
....~

«~

Figure 15.

Locality map of the Kotanbetsu

area,
readers refer to Matsumoto et at, (1978),Loc. IA2119, Topographic map of the Kiritachitoge Quad, (1 : 25000), Long, 142"00'50"E, Lac 44'11'
50"N, A cliff on the roadside of the National Highway, Route 239, about 2000 m northwards from
Yukimi Bridge, Kotanbets area (Tomamae-machi,
Tomamae-gun), northern Hokkaido (Figure 15),
Upper part of the Member Uy3 (Geological map of
the Soeushinai Quad" I : 50000, 1965 (= Member F of
Inoma, 1969) of the Upper Yezo Group, Upper
Coniacian or Lower Santonian,Loc. IA2133. Topographic map ditto, Long, 142'
00'52"E, Lac 44'11'25"N. A left bank of the
Futamata-zawa about 1000 m upstream from theconfluence with the R, Kotanbetsu, Lower part of
the Member Uy4 (Hashimoto el al., 1965) of theUpper Yezo Group, Lower Santonian (Figure 15),
The following localities with RH number, are all in
the Haboro area, For the locations in detail andstratigraphy of this area, readers may refer to Toshimitsu (1985, 1988) and also Okada and Matsumoto(1969),
Loc. RH1287p, Topographic map of the Haborodake Quad, (I : 25000), Long. 142'OO'09"E, LaL 44"
17'09"N. Upper reaches of the R, Sakasa-gawa, atributary of the R, Haboro, about 150 m upstream
from the confluence with the Yutakazawa, (Haboromachi, Tomamae-gun), in the sequence of the Lower
Haborogawa Formation (Toshimitsu, 1985), but thestratigraphic position exactly unknown, presumably
Upper Coniacian (Figure 16),
Loc. RH1271a, Topographic map of the Horobetsu-yama Quad, (I: 25000), Long, 14I'59'57"E, Lac
44'16'44"N, A cliff on the right bank of the upper
reaches of the R, Sakasagawa, about 800 m downstream from the confluence with the Yutaka-zawa,
Sandy siltstone bed below the sandstone member ofMHs3 of the Middle Haborogawa Formation of theUpper Yezo Group, Lower part of the Santonian(Figure 16),
Loc. RH 1275 (= R371 of Okada and Matsumoto,1969), Topographic map of the Haborodake Quad,(1 : 25000), Long, 142'OO'09"E, Lac 44'16'42"N, A
cliff on the left bank about 300 m upper reaches fromloc. RHI271. Sandy siltstone bed above the sandstone of MHs2 of the Middle Haborogawa Formation, Lower part of the Santonian (Figure 16),
Loc. RH1429a, Topographic map ditto, Long, 142"
00'39"E, Lac 44'17'l0"N, A cliff on the right bankof the upper reaches of the Yutaka-zawa, about 1000m upstream from the confluence with the R, Sakasagawa, Upper part of the Lower Haborogawa Formation of the Upper Yezo Group, Upper Coniacian(Figure 16),
Locs. RH2506 and 2148a2, Topographic map of the
Horobetsuyama Quad, (I : 25000), allocated along the
R, Nakanofutamata-gawa, a tributary of the R,
Haboro. Loc, RH2506: Long, 14I'58'50"E, LaC 44'
17'55"N, About 600 m downstream from theconfluence with the Machiyoi-zawa. Sandy siltstoneof the Middle Haborogawa Formation of the Upper
Yezo Group, immediately below the sandstone bed ofMHs3 at the top of the same member, Lower part of
the Santonian,Loc. 2148a2: Long, 14I'59'40"E, Lac 44'17'47"N,
About 1000 m upstream from the confluence with the
Machiyoi-zawa, Sandstone bed of MHsl of the
Middle Haborogawa Formation, Upper most of theUpper Coniacian or basal part of the Lower
Santonian (Figure 16),
Loc. RH2411d. Topographic map ditto, Long, 141'
59' 19"E, Lac 44' 18'05"N, A stream floor of theMachiyoi-zawa, about 700 m upstream from theconfluence with the R, Nakanofutamata-gawa, Mudstone bed immediately below the sandstone bed MHs2of the lower part of the Middle Haborogawa Formation, Middle part of the Santonian (Figure 16),
Loc. RH7106a. Topographic map ditto, Long, 141'

900.
141°56'Inoceramus (Platyceramus) mantelli

509

59'

57'

142°00'

RH7242b
RH7241aa-,jlla

~a'~
r:,'b

.jt'V

.§

HABORO AREA I
0.

~44°19'

1000m.
141°59 '141°58'

HABORO AREA II
44 ° 15 ,RH404Ebo

1000m=-=-........;;;j'

16'

1;;;'

Figure 16.

Locality map of the Haboro area.

58'00"E, Lat. 44'19'55"N. A left bank of the upper
reaches of the Detofutamata-gawa, a tributary of the
R. Haboro, about 1050m upstream from the confluence with the Pisshiri-zawa. Siltstone bed of thehighest part of the MHs5 member at the top of the
Middle Haborogawa Formation. Middle part of theSantonian (Figure 16).
Loc. RH7241a. Topographic map ditto, Long.

l4I'58'51"E, Lat. 44'19'49"N. A cliff on the leftbank of the Pisshirizawa, about 2500 m upstream
from the confluence with the Detofutamata-gawa.
Sandstone bed of the lower part of the Upper Haborogawa Formation. Upper part of the Santonian (Figure 16).
Loc. RH2441. Topographic map of the Haborodake
Quad. (1 : 25000), Long. 142'00' 19"E, Lat. 44'18'25"

510

Masayuki Noda and Seiichi Toshimitsu

N. A cliff on the right bank of the Machiyoi-zawa,
about 2500 m upstream from the loc. RH2411.
Mudstone bed immediately below the sandstone
member of the MHsl of the Middle Haborogawa
Formation. Upper part of the Middle Coniacian(Figure 16).
Loc. RH2480. Topographic map ditto, Long. 142°
00'09"E, Lat. 44°\8'18"N. A cliff on the forestry
roadside along the Machiyoi-zawa, about 600 m
southwestwards from the loco RH2441. Mudstone
bed immediately below the sandstone member ofMHs2 of the Middle Haborogawa Formation.
Lower part of the Santonian (Figure 16).
Loc. RH4046p. Topographic map of the Hakutozan
Quad. (Kiritachi Quad.) (1: 25000), Long. 14n'9'
39"E, Lat. 44°14'47"N. Pebble in the upper reachesof about 30 m upwards from the terminal of theforestry road along the Otodozawa, a tributary of the
R. Haboro. In the sequence of siltstone bed of the
middle part of the Upper Haborogawa Formation.
Stratigraphic position exactly unknown.
Loc. RH5047c. Topographic map ditto, Long. 141°
59'34"E, Lat. 44°13'26"N. A river floor of the
Chimei-zawa, a tributary of the R. Haboro, about 150
m upstream from the confluence with the Hakutozawa. Sandy siltstone bed immediately below thesandstone member UHsl of the lower part of theUpper Haborogawa Formation. Upper part of theSantonian.

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Masayuki Noda and Seiichi Toshimitsu

512

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Staatl. Mus. Min.-Geol., vol. 12, p. 13-207, pis.
1-14.
Vokes, H.E., 1967: Genera of the Bivalvia: A systematic and bibliographic catalogue. Bull.
Amer. Paleont., vol. 51, no. 232, p. 105-394.
- - , 1980: Genera of the Bivalvia: A systematicand bibliographic catalogue (Revised and updated). 307p. Paleontological Research Institution,
Ithaca, New York. U.S.A.
VOllte, c., 1954: Les Inocerames de L'Algerie.

Nouvelles observations au sujei de Inoceramus
algeriensis Heinz emend. VOllte et de quelques
autrs especes - - C .R. Congr. geol. in tern at.
Alger. 1952, Sect. XIII, 3 part, p. 149-155.
Woods, H., 1911, 1912: A monograph of theCretaceous Lamellibranchia of England: InoceralIlUS. Palaeol1lgr. Soc. Mon., London, vol. 2,part 7, p. 250-284, pis. 45-50 (1911); part 8, p.
285-340, pIs. 51-54 (1912).

Amakusa '}(11f., Asahikawa mUll, Banno-sawa ~ / iR, Chimei-zawa 9;-[]iPiR,Detofutamata-gawa T' r =~JII, Futamata-zawa =ll9:iR. Haboro
Haborogawa +I$J/;JII.
Haborodake +lm-ffi. Hakutozan aMID. Hakuto-zawa aMiR. Hidarimata-zawa tr.
~iR. Hinoshima tili / !th. Hiromine-zawa J.tWifiR. Hobetsu %tt5JIJ. Horobetsuyama
5JIJLlJ. Ikushumbets ~1f;5JIJ. Iwamizawa :E Ji!.iR. Kamihobetsu J:%tt.5JIJ, Katsurazawa tt
iR. Katsurazawako ttiRliVl. Kiritachi ~:tz:. Kiritachi-toge ~:tz:iI!t. Kotanbetsu tift
5J1j. Machiyoi-zawa f~'j!jiR. Matsuyama f£-LlJ. Mikasa :==::i't.. Monobe !l&.Jlm. Nakanofutamata-gawa r:p / =~JII. Nutapomanai ;;<!J;f- -< T -1. Okuhidarimata-zawa ~tr.1l9:
iR. Omagari-zawa :*: ElEiR. Ominegadai :*:~ 'T t!i.
Onkono-sawa ;t :/ ::I / iR. Osawa:&fIJ. Otaru 'HlJ. Otodo-zawa :*::tfttiR. Pisshiri-zawa 1::' -:J : / ~ iR. Pombets ~ 5J1J.
Pombets-gono-sawa ~5JIJ:n./ iR. Sakasa-gawa JiEJII. Soeushinai ~tti1'J. Takino-sawa~ / iR. Takiyoshi-zawa ~EiR. Tomamae-gun -.5Mtl1I. Tomamae-machi -.5MIHJ. Yezo
~ '/ (~~) • Yubarigoe-zawa ~iJ&~iR. Yukimi-bashi ~Ji!.1ilii. Yutaka-zawa 1!!I:iR

+1m.

m

B:$:i£a.9E*c Inoceramus (Plalyceramus) mantelli de Mercey i:::'/)\"-C: :$:~IfH"'efi~tliiJ.
:1![~J1!!.ii'I?i£1.....t.: I. (P.) mantelli de Mercey, 1877 O)~< O)~:$:i:::'/)\"-CO)Wl.~H:::.JJQ*--C
1=.!l&.JiRIjIE~!¥J Ji!.J1!!.ii, I?.;c O)!fif~~,*gg 1.. . -C ~ t.:o .;c O)HH~Hj,: 0) J: ? tt.;:' t ii~li1H2, ~:Ie t.:o {ft~ tLt.:fiO)!fif~~:::.~n *- -C \"/)ii,0);JfJ111):::' /)\" -C ~~O)~lilii~~ I? ii'l:::' tt. -') t.:o B:$:
ii'I?i£1.....t.::$:fiO)~:$:fi;:':le1-c·I. (P.) yubariensis Nagao et Matsumoto, 1940 C 1.....-Ct&:btL -C ~ t.: ii'. 3 - P -:J /~ 0) b 0) C t ,*IE~ t, J%'IJD-C tF*SH:::..ltti: 1.. . tda* • .;c 0);JfJ1l]J:0)Jtj);\" fifi 0) l/"" /v-c'alR5J1J 1.....it!h';:' C ii'~ I? ii'i:::' tt. -') t.:o {ft -') -C. I. (P.) yubariensis O)fiof,a I. (P.) mantelli O)tT~:/ / =- J,. c \"? ;:. C ~:::.tt.oo ~Jf~!¥Ji:::.a:$:fili 3 - P -:J /~ tt.1?
lfi:::'.;c O)!jlt}JJ1!!.~-C'li ::I =- 7 :/ 7 :/~j§-O)~~*ii' I?i£ 1.. .
0 ii~. B :$:-c'fi:;5=t to tL

*xmt

<

-c \"

< -c

=- :/ 7:/ J:lmii' I? -IT:/ r =- 7 :/ I:::'ii,ft-C ilIH:I:l-t 0 :$:fiO))ttllmH:::. /)\, '-C fi4-O) PHIi1H;2,~ tL -C \" tt. \" ii'. :$:fi fi -IT:/ r =- 7 :/ ~ tJ :/ /~ =- 7 :/ ~j§-O) ~ <0) Inoceramus (Platycer::I0amus) O)fii:::.xt1.....-C~jjfjO). t5o\"fi9'j;jiO))ttlli:::.t5t.:o c~*-I?:leoo!I!-.r!fl~1t;~.• flj:J't~-oTrans. Proc. Palaeont. Soc. Japan, N.S., No. 158, pp. 513-534, 16 Figs., June 30, 1990

901.

PARAMETERS FOR DESCRIPTION OF THE SHELL FORM
OF THE GENUS ANADARA (MOLLUSCA; BIVALVIA)*OSAMU SASAKI
Institute of Geology and Paleontology, Tohoku University,
Sendai, 980.

Abstract. Ontogenetic change in morphological features of Anadara shells is analyzed
on the relationship between 4 proportions of portions of shell and shell size. These
relational changes are interpreted in the framework of the shell coiling model; ontogenetic
change in the shape of cardinal area and teeth arrangement represents a change in revol ution
around the coiling axis, whereas ontogenetic change in the proportion of the anterior andposterior toothed hinge lengths represents a change in the shape of the commissure.
The taxonomic criteria of the genus Anadara are proposed based on similarities of the
ontogenetic change in shell shape. The extremely variable population of Anadara ninohensis in the Kubota Formation (Middle Miocene, Fukushima Prefecture) has previously beenclassified into three species. Analysis of the ontogenetic variation shows that all Kubota
specimens fall into the single variable species Anadara (Anadara) hataii Noda, and theother population from the Kadonosawa Formation (lower Middle Miocene, Iwate Prefecture) is placed in the subgenus Scapharca.
Key words.

Anadara, ontogenetic change, shell coiling, shell form.

taxa (Thompson, 1942; Owen, 1953;
Rudwick, 1959; Stasek, 1963; Raup andMichelson, 1965; Raup, 1966). In suchstudies, some equations are written that
describe ontogenetic change in an idealized
form. The advantage of these mathematical
approach is that the factors of ontogenetic
change in form can be appreciated throughthe equations within the framework of thecoiling models.
Several sets of parameters have been suggested to describe differences and similarities
between coiled forms. However, there havebeen few if any successful applications of thisknowledge to the problems facing the description and classification of coiled forms. One
reason is that the shell form has been represented by a logarithmic spiral in themodels. However, many shells change in themode of its spiral throughout ontogeny, sothat they grow exactly in a non-logarithmic

Introduction

The molluscan shell is a product of secretory activities operating throughout growth.
The secreted shell is retained from stage tostage and the form becomes integrated atevery stage. It must be emphasized thatbivalve shells retain the same shape throughout growth is only an approximation to thetruth. Many studies of the shell growth lines
indicated a slight progressive change in shapeas the valves grow. Molluscan forms, therefore, should be described "dynamically" insuch a way that the description emphasizes
the sequence of ontogenetic changes, and thedescription and classification of shells should
be based on the constraints of growth.
Mathematical methods have been used inmorphological studies of molluscs and other• Received October 24,
accepted May 10, 1990

1989; revised manuscript513

Osamu Sasaki

514

mode. This logarithmic growth assumptionof the models, then, makes them difficult touse for the analysis of molluscan shells In
nature.
The purpose of the present paper is to
propose some taxonomic criteria of the genus
Anadara based upon similarities in the
ontogenetic sequence. The primary objective of this study is to publish the parameters
for the description of ontogenetic change inthe morphology of Anadara species. Similarities and differences in ontogenetic change
will be examined in the taxonomic categories
proposed in Anadara by Noda (1966).
Finally, an attempt will be made to discriminate two species by using the similarities anddifferences of their ontogeny.

b,beak position

Definitions
The shape of the shell, and the shape andorientation of the taxodont teeth are usefulmorphological features for taxonomic discrimination in Arcidae (Reinhart, 1943).
The shape of the shell is described by the
degree of inflation of the shell, the position of
the beak, and degree of the curvature of theanterior, posterior and ventral margins. Theintervals of various parts of the shell measured in this study are defined here in order todescribe the features of the shell.
Figure la shows the shape of the shell of
the genus Anadara in interior view. TL is
the length of the toothed portion of the hingeline. AM and PM are the heights of theanterior and posterior margins. The absoIute size of the specimen is represented by thelength of the toothed portion of the hinge line
(TL). Figure I b shows the shape of the cardinal area. CH is the height of the cardinalarea.
The inflation of the Anadara shell is represented by the ratio between the height(CH) and length (TL) of the cardinal area.
The degree of curvature of the anterior andposterior margins is represented by theirheights (AM and PM).

Figure 1. Linear dimensions measured for the
analysis of ontogenetic change in shell form. la,
TL: length of the toothed portion of the hinge line.
AM, PM: heights of the anterior and posterior
margins of the commissure. lb, CH: height of the
cardinal area. Ie, EV: length of the divergenttoothed portion of the posterior teeth segment. ld,
PT, CT, AT: lengths of the posterior, central andanterior segmental teeth series.

The hinge plate of Anadara species isstraight or moderately arched and is locatedjust below the cardinal area. The numerous
taxodont teeth lie transverse to the hinge
margin. Two major features of the hinge
teeth are considered; I) the mode of arrangement, and 2) the ratio between the lengths ofthe parts of the toothed hinge anterior andposterior to the beak.
Figure Ic shows the arrangement of the901.

Parameters for description of genus Anadara

hi nge teeth. The taxodont teeth of the gen us
A nadara were classified into three types byReinhart (1943) based on their shape andtheir inclination to the hinge line: convergent teeth, divergent teeth, and v-shaped teeth.
As shown in Figure Ic, the divergent teeth areat the center of hinge line, the convergent
teeth at both extremities, and the v-shaped
teeth between the other two types. EV is thelength of the divergent-toothed portion of theposterior hinge line.
Noda (1966) classified the arrangement of
taxodont teeth of the genus Anadara into
three categories based on the combination of
the tooth types of Reinhart (1943); he recognized the ventrally convergent type, the divergent type, and the divergent type with vshaped teeth. These types of tooth arrangement are represented by using the ratio of thelength of the divergent toothed portion to thelength of the posterior segment of the hingeline (EV jPT).
Figure ld shows the change in tooth size
along the hinge line. The toothed portion of
the hinge line can be divided into three segments by two points where the size of theTable 1.

teeth changes discontinuously. PT is thelength of the posterior segment of the toothed
portion of the hinge line, CT is the length ofthe central portion, and AT is the length of
the anterior one.
The position of the beak is traditionally
represented by the proportion between thelengths of the anterior and posterior parts ofhinge line. The point that divides the central teeth segment from the anterior segment
corresponds well to the position of the beakon the hinge line, especially in young shells(ex. specimen I in Figure 2). Therefore, thebeak position is represented by using the
proportion of the length of the anterior
toothed segment to the length of the toothed
portion of the hinge line (AT jTL) in thispaper.

Material
The basic data used in this study comprisebiometry of 3 subgenera and 15 species (Table
I). Populations of these species wereselected for measurement by the following
restrictions. Firstly, many specimens of one

Stratigraphic distributions of the Anadara species studied here.

specific nameAnadara(Anadara)

A.
A.

(A.)
(A.)

A.

( Hataiarca)
(H.)

A.

515

formations

age

amiclila elongala Noda
halaii Noda

Sasaoka, Omma

Pliocene, Pleistocene

KubotaMiocenehokkaidoensis Noda

Chokubetsu, Okkoppezawa

Miocenekakehataensis Hatai and Nisiyama

Kurosedani, Sunakozaka

Miocenekogachiensis Noda

Haneji

Pleistocene

A.

(H.)

sllbcrenata (Lischke)

Recent, Narita

Recent, Pleistocene

A.

(H.)

pselldosllbcrenala Ogasawara

Omma

Pleistocene

A.

(Scapharca)

cf. satowi (Dunker)

Omma

Pleistocene

A.
A.
A.

(S.)

Omma

Pleistocene

(S.)

A.

(S.)

ommaensis Otukan. sp.
brollghlonii (Schrenck)
taiwanica Noda

A.

(S.)

A.
A.

(S.)

Koyu

Pliocene

Recent, Narita

Recent, Pleistocene

TokazanPliocene

Heiroku, Kurosedani

Miocene(S.)

makiyamai Hatai and Nisiyama
ninohensis (Otuka)

Kadonosawa

Miocene(S.)

Iricenicosla (Nyst)

Recent, Tokazan

Recent, PlioceneOsamu Sasaki

516

o

_0

-

-

Figure 2. Ontoge netic variation of Anadara (Hawiarca) kakehataensis Hatai and Nisiyama from theSunakozaka Formation in Toyama Prefecture. Sca le bar = 5 mm . Symbols indi cate the dimen sions
mea sured in the hinge teeth, as shown in Figure I.

species must be available from one locality;
the effects of geographical and evolutionalvariations were thereby minimi zed. Secondly, the number of specimens must be large
enough to be treated statistically. F in ally,
the specimens must demon strate considerable
ontogenetic variation with shell size; therange of ontogenetic variation was maximized.

Ontogenetic change in the shape of shell(a) Shape of the cardinal area
Figure 2 shows the shapes of the cardinal
area of Anadara (Hataiarca) kakehataensis
Hatai and Ni siyama at different growthstages. In juvenile shells, the cardinal area isa lo w triangul a r shape, but it becomes pro gressively taller as the shell grows. Such achange can be represented by the change inthe ratio between the height (CH) and length(TL) of the cardinal area. This relation ship

901.

o

Paramelers for descriplion of genus Anadara

-

o

-

517

-

Figure 3. Ontogenetic vari inion of Anadara (Anadara) amicula elongalG Noda from the Om rna
Formation in Ishikawa Prefecture. Symbol s as in Figure I.

is plotted in Figure 4a. The plotting of TL
against the log of CH produced a linear arrayof points at TL < 23 mm , and a curved array
at TL < 23 mm; the linear array of points
suggests that the cardinal area grows in alogarithmic mode at TL > 23 mm. The modeof growth in the cardinal area is not constantthroughout ontogeny , and for this species, itchanges at a TL value of 23 mm.
Figure 3 shows the shapes of the cardinal
area of Anadara (Anadara) amicula elongala Noda. The relationship between TL
and log CH of this species is plotted in Figure
4b. The logarithmic growth of the cardinal

area can be observed at TL values greaterthan 12 mm. For A. (A.) amicula elongala,the growth mode changes at a TL value of 12mm.
These examples indicate that the cardinal
area changes in its growth mode throughontogeny ; that is , the cardinal area grows in
non-logarithmic mode during the juvenilestage, and in logarithmic mode during thepost-juvenile stage. Such change in growthmode is observed in other A nadara species(Table 2). Therefore, the value of TL atwhich the growth mode changes is a usefulparameter for the description of ontogeny ofOsamu Sasaki

518

b

a
4

E

3

0

-

2

E

-1

-

:I:

-2

-

-3

I-

-1

-4

I-

-2

-5

I-

!.

!.

:I:
0

0

DI

DI

0

!!.

!!.

-3

"
N

40

a

DI

1o

.-

~.gJS)-oo-~'o' a
a

_-

_o-

.t
:;
.
N

·iii

:f~~~

"tI

ClID 00<llJll

I

I

-6

20

0

P.O-

·iii

20

0

T L (Riml

40

TL{mm)

d

C

0.8

-

a
6 a
a 000

oClo°

-co- _;!; 0.7" oCCo 8_1l'I _a.~- _0- f)-O(j a

;!;

, 0.6

<0.:,"0- "()-.o;.

Q.

;!;

a

<C

-;:; ~"'O

ScPo

.'0

a '<YO ~

~

-

....

a a a c9a a c!P;!;<C

a ~ ~o_ _0_<e5'- 9.o~-g- _.g- -- -09
a00---0-0-

<D

00

Q.

0.4

,.. a

00

a

a

oc:fO

a

0.4

I

0.2
0

20

I

I

0.1
40

TUmml

o

40

20

TL (mml

Figure 4. a, b: Distribution of ontogenetic variation with respect to the relationship between theheight (CH) and length (TL) of the cardinal area. Logarithmic growth of the cardinal area, represented bybroken line, occurs at greater than log sizes (when EV IPT =0). c, d: Ontogenetic change in the ratio
between the heights of the anterior (AM) and posterior (PM) margins of the commissure. Broken lines
represent linear change in mean value of the ratio in adult shells. a, c; Anadara (Hataiarca) kakehataensis Hatai and Nisiyama. b, d; Anadara (Anadara) amicula elongata Noda.

the cardinal area of Anadara, and the TL
value at which the growth mode changes isnamed a log size.
(b) Shape of the commissure
Specific cases of variation in the shape ofthe commissure fall practically into two categories: either variation in the ratio between
the height and length of the commissure, orvariation in the ratio between the heights ofthe posterior and anterior parts of thecommissure. The majority of ontogenetic
changes in the shape of the commissure observed on Anadara species occur in the ratio
between the heights of the posterior andanterior parts of the commissure (AM/PM).
Variation in the shape of the commissure

for Anadara (Hataiarca) kakehataensis is
illustrated in Figure 2. In the juvenile stage,
the posterior margin is higher than the anterior margin; the commissure has a distinctly
inequilateral form. The commissure becomes progressively more equilateral as theshell grows. Such ontogenetic change can be
represented by the change in the ratio
between the heights of the anterior and posterior margins (AM/PM). The AM/PM and
TL data were plotted as a scatter diagram inorder to examine whether there is a correlation between them. Figure 4c shows thescatter diagram for A. (H.) kakehataensis.
The correlation between AM/PM and TL is
positive for this species; that is, TL increases

901.

Parameters for description of genus Anadaraas AM/PM increases.

519(a) Arrangement of the hinge teeth
Arkell (1930) reported that the arrangement of the hinge teeth of the Glycymerididae
and Cucullaeidae was the divergent type withv-shaped teeth in adult shells, which changed
progressively from the convergent type injuvenile shells as the shell grew. Such achange in the teeth arrangement can be observed also in the ontogey of Anadara
species.
Figure 2 shows the arrangements of hinge
teeth at a variety of growth stages inA nadara(Hataiarca) kakehalaensis. In the juvenilestage, the arrangement is of the convergent

type. The shape of the teeth is transformed
into v-shaped teeth, and into divergent teeth
along the central part of the hinge line, progressively further outward as the shell grows,
so that by the adult stage, the arrangement of
the teeth becomes the divergent type withv-shaped teeth. Change in the arrangementof teeth will be represented here by change inthe ratio of the length of the divergent
toothed portion to the length of the posterior
toothed portion of the hinge line (EV /PT).
If a shell has the convergent type of teeth
arrangement, the value of EV /PT will be O.
As the arrangement changes from the convergent type to the divergent type with v-shaped
teeth, the value of EV /PT increases progressively, and finally approaches the maximum
value (EV/PT=I). The shell size at whichab

Ontogenetic change in hinge teeth

I-

I-

a.

a.
>

:> 0.5

"

w

0.5

w

0

0
0

20

40

0

40

20
T L (mmJ

TL(mml

C

d
0.6

0.5

0.4

0.5

...J

I-

...J

I-

"«

0.3

I-

0.2

I-

I-

0.2

I

0.1
0

0.4

"
« 0.3

I-

I
20

0.1
40

o

I

(

20

40

T L rmmJ
TL (mml

Figure 5. a, b; Distribution of ontogenetic variation in teeth arrangement represented by change in thevalue of EV /PT. When EV /PT=O, a shell has the convergent type teeth arrangement, and when EV /PT>
0, the divergent type with v-shaped teeth arrangement. c, d; Growth change in the ratio of the length of theanterior teeth segment to the length of the toothed portion of the hinge line, which represents the migrationof the beak position. a, c; Anadara (Hataiarca) kakehataensis Hatai and Nisiyama. b, d; Anadara(Anadara) amicula elongata Noda.

Osamu Sasaki

520

Table 2.

Biometorical data for Anadara species studied here.

specific namesize

TL (0)TL (0.75)%

Adult size
(TL (0.75))
EV /PT=0.75

Log size(TL (0))EV /PT=O

relative

TL
(mm)

AT/TL

CH/TL

TL
(mm)

AT/TL

CH/TL

Anadara (Anadara) amicliia elongata Noda

27

12

.075

.36

45

.222

.42

A. (A.) hataii Noda

30

15

.066

.4

50

.22

.39-.43

A. (A.) hokkaidoensis Noda

31

14

.1

.4

45

.266

.45

A. (Hataiarca) kakehataensis Hatai
and Nisiyama

63

23

.145

.31

35

.242

.35

A. (H.) kogachiensis Noda

71

32

.141

.38

45

.222

.4

A. (H.) sllbcrenata (Lischke)

51

23

.87

.31-.445.188.38-.42

A. (H.) pselldosllbcrenata Ogasawara

51

18

.111

.29

35

.188

.38

A. (Scapharca) cf. satowi (Dunker)

60

30

.77

.33

50

.15

.4

A. (5.) ommaensis Otuka

50

22

.136

.28

44

.148

.37

A. (5.) n. sp.

48

16

.057

.27

33

.121

.28

A. (5.) brollghtonii (Schrenck)

46

30

.05

.34

65

.154

.38

A. (5.) taiwanica Noda

56

25

.075

.32

45

.12

.35

A. (5.) makiyamai Hatai and Nisiyama

51

18

.14

.3

35

.186

.34

A. (5.) ninohensis (Otuka)

61

20

.1

.32

33

.152

.38

A. (5.) tricenicosta (Nyst)

52

30

.1

.31

58

.152

.36

TL (O)/TL (0.75): relative size, which is the ratio between the lengths of the tothed portion of the hinge line at
EV /PT=O and at EV /PT=0.75. TL: length of toothed portion of hinge line. AT /TL: ratio of the length of
the anterior teeth segment to the length of the toothed portion of the hinge line. CH/TL: proportion of theheight (CH) to the length (TL) of the cardinal area. EV /PT: ratio of the length of divergent-toothed portion of
the posterior teeth segment to the length of the posterior teeth segment.

the arrangement changes to the divergent typewith v-shaped teeth is named a critical size.
The relationship between EV jPT and TL
in A. (H.) kakehataensis is plotted in Figure
5a. The value of EV jPT is constantly 0 at
TL < 23 mm. As TL becomes greater than 23mm, the value of EV jPT progressively increases and approaches the maximum value(EV jPT= I). For this species, the criticalsize of EV jPT is TL=23 mm.
Figure 3 shows tooth arrangements of A.
(A.) amicula elongata. The relationshipbetween EV jPT and TL is illustrated in
Figure 5b. For this species, the critical sizefor the change in EV jTL is TL = 12 mm.
Ontogenetic change in the tooth arrangement can be observed in other Anadara
species, and measured values of the criticalsize of the species are shown in Table 2.
(b) The ratio between the lengths of thehinge anterior and posterior to the beakFigure 2 shows the ontogenetic variation in
hinge teeth for A. (H.) kakehataensis. In
the juvenile stage, the beak is located at theanterior fourth to third of the hinge length,
but it shifts progressively during ontogeny sothat by the adult stage, the beak is locatednear the center of the hinge line.
Figure 5c is a scatter diagram on which the
AT jTL and TL data for all the specimens ofA. (H.) kakehataensis are plotted. The relationship between AT jTL and TL is positive;that is, as TL increases, AT jTL increases.
This ontogenetic change in the proportion of
the lengths of the anterior and posterior
portions of the hinge (i.e., backward migra-

901.

Parameters for description of genus Anadara

521

tion of the beak) occurs also in all otherA nadara species.
f-Relationship between the ontogenetic
changes in the shape of shell and in
the features of hinge teeth

~ 0.5
>
w

Ontogenetic changes in the shape of theshell and in the features of the hinge teeth areobserved in Anadara species. The relationship between these two types of ontogenetic
change is examined as follows.
(a) The relationship between the changes
in cardinal area and in tooth arrangement
Figure 6 shows the relationship between
EV /PT and CH/TL for Anadara (Hataiarca) kakehataensis. The plotting of EV /PT against the log of CH/TL produces alinear array of points at EV /PT>O. This
linear relationship suggests that the value of
EV /TL depends on the value of CH/TL at
EV /PT > 0; that is, the ontogenetic change
in the shape of the cardinal area has the effectof transforming the arrangement of the hinge
teeth. This dependency between these characters is shown also by comparing the valuesof the critical size of the arrangement of thehinge teeth with the log size of the shape ofthe cardinal area; for example, in A. (H.)
kakehataensis, the critical size measured in
ontogenetic change in EV /PT is 23 mm,
a

o
-3.2

-2.4

-2

log

-1.6

-1.2

CH/Tl

Figure 6. Relational change between the teeth
arrangement (EV /PT) and the shape of the cardinal
area (CH/TL) for Anadara (Hataiarca) kakehataensis Hatai and Nisiyama.

which is equal to the log size of change in
CH/TL. The critical and log sizes, which
are defined on different ontogenetic features,are nearly equal in other Anadara species aswell (Table 2).
(b) The relationships between ontogenetic changes in the proportion of the commissural margins and the hinge line
A positive correlation exists between AM/
PM and TL distribution (Figures 4c, d).
This correlation thus produces a positive
correlation between AM/PM and AT jTL.
Figure 7a shows the correlation between themfor A. (H.) kakehataensis, plotted as a scatter
diagram. The positive correlation between
AM/PM and AT /TL suggests that the
ontogenetic change in the shape of the
b

O.B
0.7
I- 0.6
11.

:: 0.5u;::: 0.4
-0:

0.3

rrr-

o ~~s:o_ .0-0- if-o 0 o~~tpc@'o 8

6 @08
8 0
0

__ - 0 - __ 0000

Q

0.2

I

0.1
0.3

0.5

I
0.7

0.9

-

5 mm

-

1 0 mmFigure 7. a; Linear relationship between ontogenetic changes in the ratio of the two ratios relating
shapes of posterior and anterior parts of the shell (anterior to posterior hinge length, AT /CT + PT; heights
of anterior and posterior commissural margins, AM/PM) for Anadara (Halaiarca) kakehalaensis Hatai andNisiyama. b; Model of ontogenetic change in the shape of the commissure.

Osamu Sasaki

522

commissure is shown by a change in the ratio
between the squares of the anterior and posterior parts of the commissure (Figure 7b).
Therefore, the ontogenetic change in the
shape of the commissure can be represented
by change in the ratio of the lengths of the
portions of the hinge anterior and posterior
to the beak (AT /TL).
Parameters for the descriptionof Anadara shell morphology
In the light of the coiling shell model, thegeometry of a shell can be described by the
relationships between several parameters.
Owen (1953) resolved the growth direction at
any point on the shell margin into threecomponents: 1) a radial component radiatesfrom the umbo in the plane of the generating
curve, 2) a transverse component expresses thetransverse effect of the revol ution of the planeof the generating curve, and 3) a tangential
component of growth in the plane of thegenerating curve may be expressed by a"apivoting" of the generating curve within its
plane. His model is useful to analyze theshell deformation that occurs during ontogeny. Raup and Michelson (1965) proposeda simple model for the description of a coiled
shell by using four basic parameters. They
are: 1) the shape of the generating curve (S),2) the whorl expansion rate (W), 3) the position of the generating curve in relation to thecoiling axis (D), and 4) the rate of whorltranslation (T). The four parameters areclassified into two categories; parameters forthe description of shell coiling (0, Wand T),
and parameters for the description of the
shape of the commissure (S). The simplicityof this model makes it easy to visualize shellforms through computer simulations.
Computer-drawn pictures serve as a framework through which different forms may becompared.
Figures la, b show the intervals of Anadara shells measured here. These intervals arecompared with the parameters of the twomodels, and the coiling shell model is used asa framework through which the ontogenetic
changes in the shape of Anadara species may
be appreciated. As noted above, the cardinal area and the commissure change in shapeduring ontogeny in A nadara species.
In a transverse section of an A nadara shellthrough the beak and the center of the ventral
margin, the surface of the shell and the cardinal area are described by two spiral curves.
One of them, the spiral curve of the cardinal
area is considered here; the height of the
cardinal area (CH) corresponds to the distance from the coiling axis to the generating
curve (D) of Raup and Michelson's model,
and to the integrated transverse componentsof Owen's model of the spiral curve of the
cardinal area. The length of the toothed
portion of the hinge line (TL) corresponds to
the radius of the generating curve of Raupand Michelson's model. Therefore, the differentiated TL is the whorl expansion rate(W) of Raup and Michelson's model, and thedifferentiated TL is also equal to the radial
component of Owen's model.
The CH-TL relationship, which represents
the change in the shape of the cardinal area,
can be compared with the O-W relationshipof Raup and Michelson's model. A change
in position on the 0- W plane of Raup's(1966) morphological space expresses achange in the degree to which the shell
becomes evolute. Similarly, for the Anadara shell, an increase in the value ofCH/TL
expresses an increase in the degree of shellinflation.
If the increasing rate of CH/TL increases
constantly during ontogeny, the end of the
cardinal area traces a logarithmic spiralcurve, so that the shape of the spiral can be
expressed simply by the increasing rate of alogarithmic spiral [CH=exp. (a*TL): a=canst. J. However, the rate of the increase of
CH/TL is not constant for Anadara species;
ontogenetic change of the cardinal area showsthat non-logarithmic growth occurs in thejuvenile stage and logarithmic growth occurs

901.

Parameters for description of genus Anadara

In the post-juvenile stage. The shell shapeproduced by non-logarithmic growth can bechanged by changing the ratio between thelengths of the juvenile and adult stages,
without changing the shell inflation; theproportion of the length of the juvenile stage
to the length of the completed adult shell
involves basic information on the shape of
non-logarithmic growth. [t is required in
non-logarithmic growth that the scale ofgrowth is defined in order to calculate theproportion of the lengths of growth stages.
The value of EV /PT is a useful marker ofshell growth, because EV /PT value increases
depend on CH/TL value during logarithmic
growth but not on absolute shell size. Therefore, the nature of shell coiling of Anadara
species can be described by using sets of CHI
TL and EV /PT values.
The shape of the commissure of Anadara
species is described by using two ratios;
AM/PM, the ratio of the heights of the anterior and posterior margins, and AT /TL, theratio of the lengths of the anterior and thewhole toothed portions of the hinge margin.
Therefore, these two ratios correspond to thedescriptive parameter for the shape of thegenerating curve (S) of Raup and Michelson'smodel.
The primary factor in deformation of the
shape of the commissure is asymmetricalsecretion about the antero-posterior axis of
the margins. [n Raup and Michelson'smodel, ontogenetic change in the shape of thecommissure (S) would be represented byasymmetry of the magnitude of the expansion
rate of the commissure (W) about the anteroposterior axis. In Owen's model, the gradient of the tangential component along theaxis generated the ontogenetic change. Thechanges in AM/PM and AT /TL express thechange in ratio of the squares of the anterior
and posterior parts of the commissure plane.
Therefore, the differentiated AM/PM andAT /TL over growth time corresponds to theratio of W val ues at the anterior and posterior
parts of the commissure, and to the gradient523

of the tangential component along the anteroposterior axis. Thus, ontogenetic change inthe shape of the commissure of the Anadarashell can be represented by using AT /TL
values.
Using these parameters, I took as an example a comparison between the shell shapes of
Anadara (Hataiarca) kakehataensis andAnadara (Anadara) amicula elongata at thelog size (EV /PT =0) and the adult size (EV /PT=0.75). At the log size (EV /PT=O); A.
(H.) kakehataensis has TL=23mm, AT/
TL=0.145, CH/TL=0.31, and A. (A.)
amiClila elongata has TL= 12 mm, AT/TL=
0.075, CH/TL=0.36. At the adult size (EV /PT=0.75), A. (H.) kakehataensis has TL=
35 mm, AT/TL=0.242, CH/TL=0.35, andA. (A.) amicula elongata has TL=45 mm,
AT/TL=0.222, CH/TL=0.42. Comparison between sets of these val ues makes it clearthat these species differ not only in absolutesize, but also in shell geometry at the same
growth stage (Table 2). The relative size isdefined as the ratio of the TL val ue at the log
size to the TL val ue at the adult size [TL(O)/TL(0.75)]. The relative size represents
approximately the proportion of the length of
the juvenile stage to the length of the completed adult shell. The value of the relative size
for A. (H.) kakehataensis is 63%, while thevalue for A. (A.) amicula elongata is 27%;
these values suggests that the shell shape ofthese species differs in shell coiling shape.
In summary, the basic elements of the shapeof shell can be descri bed by the set of parameters; EV /PT, AT /TL, CH/TL, TL and
TL(0)/TL(0.75), where
EV /PT is the ratio of the length of thedivergent toothed portion to the length of theposterior toothed portion of the hinge line,
and represents the scale of the growth stage;
AT /TL is the ratio of the length of theanterior portion to the length of the toothed
portion of the hinge line, which is a parameter for the description of the shape of thecommissure by the ratio of the squares of theanterior and posterior parts of the commis-

524

Osamu Sasaki

sure;
CH/TL is the ratio of the height to thelength of the cardinal area, which is a parameter for the description of the shell inflation;
TL(O)/TL (0.75) is the ratio of the lengthof the juvenile stage to the length of thecompleted adult shell, which describes thenature of the ontogenetic change in shellcoiling shape;
and TL is the length of the toothed portion of
hinge line, which represents the absolute sizeof the shell.

Similarities and differences of ontogenetic change in taxonomic categories
The forgoing discussion has concentrated
on the description of shell morphology froma strictly geometric viewpoint. As well as
this, the complete morphological picture of abivalve shell would include the many featuresof surface ornamentation, growth lines, internal structure, shell thickness, and so on. If
the knowledge of ontogenetic change in shell
shape is incorporated more thoroughly into
the systematic description of Anadara
species, the identification of taxonomic categories will be facilitated. Similarities anddifferences in ontogenetic change are analyzed here in the taxonomic categories
proposed by Noda (1966).
(a) Similarities and differences In
intraspecific variation
The specimens measured in this study areplaced in the 15 species recognized by Noda
(1966). Figures 4a, 4c, 5a, and 5c show the
relationships of the parameters for A. (H.)
kakehataensis. Each circle on the diagram
represents data on one specimen. The distribution of the circles is restricted to a narrow
region along the broken line. This narrow
distribution suggests that these specimens
have ontogenetic relationships in common forgeometry, growth stage and absolute size. By
contrast, the relationships of three species areillustrated in Figure 11 b. The symbols are

distributed over a wide region. The width ofthe distribution of points in these diagrams,
therefore, is useful to examine whether the
population analyzed is placed in a single
species.
An important intraspecific variation isfound in the AT /TL-TL relationship, which
represents the ontogenetic relationshipbetween the shape of the commissure andabsolute size. Figure 8 shows variation in
the shape of the commissure, and Figure 9shows the distribution of AM/PM-TL datameasured in A. (H.) subcrenata (Lischke).
The circles are restricted to a narrow region
along the line, so that the popUlation isplaced in a single species. Specimens 2 and 3
in Figure 8 are examples of intraspecific variations with respect to the AM/PM- TL relationship. Although these specimens possess
almost the same size, specimen 2 is characterized by a smaller value of the ratio AM/PM
than that of specimen 3 shown in Figure 9 ;specimen 2 has a more inequilateral commissure shape than that of specimen 3. Such an
inequilateral shape also characterizes specimen I, which is a younger than specimens 2
and 3 (Figures 8, 9). Therefore, wide
intraspecific variation is recognized in therelationship between the commissure shapeand absolute size in this species.
(b) Similarities and differences between
allied species
Some workers have proposed that JapaneseAnadara species could be divided into somegroups of closely allied species. For example, Iwasaki (1964) recognized 9 groups:
Anadara daitokudoensis group, Anadaraninohensis group, Anadara amicula group,
Anadara moriyensis group, Anadara ommaensis group, Anadara castellata group,
Anadara valentula group, Anadara tricenicosta group, and Anadara granosagroup. Similarities and differences in ontogenetic change in shell form are examined
here in 5 allied groups, as follows: Anadara(Anadara) amicula elongata group, Anadara (Hataiarca) subcrenata group, A. (H.)

90 I.

Parameters for description of genus A nadara

525-

Figure 80 Ontogenetic and intraspec ific va ri ation in the sh ape o f the commissure of Anadara (Hataiarea) subcrenata (Lischke) from th e N a rit a Formation in Chiba Prefec ture. Symbols as in Figure I.

o7

05

I

01

o

L

I

20

I
40

I
60

T L(mmJ

Figure 90 Distribution of ontogenetic andintras pecific va riation in the relation ship betwee n
AT / TL (the ratio of the lengths of the a nterior teeth
segments to too thed portion of the hinge lin e) a nd
TL (absolute size) for Anadara (Hataiarea) subcrenata (Li schke). Numbers 1- 3 o n the diagram
corresponds to numbers of specimens in Figure 8.

kakehataensis group , Anadara (Scapharca)ommaensis group and Ao (So) ninoh ensis
group.
Figure 10 shows commissure shapes ofthree growth stages for A. (H 0) subcrenata
and its al li ed species Ao (5.) cf. salOwi (Dunker) and A. (H.) pseudosubcrenata Ogasawara. The relationships between EV / PT a nd
AT / TL for these species are illu strated in
Figure 11 b. The symbo ls are restricted to anarrow region of the diagram ; the EV / PT
and AT / TL relationships of these species are
similar. The similarity of the rel at ion ships
suggests that these species are closely similarin shell form at the same growth stage.
Figure 11 a shows the relationships between
EV / PT and the abso lute size of these species.

The distinct growth paths of these three
species make it clear that the species h ave
di stinct EV / PT - TL relationships. Therefore , these three species are simi lar in shell
shape but different in absol ute size a t thesame growth stage.
Such interspecific variation with respect tothe relationship between shell shape a nd
absolute size was also observed in othergroups of a lli ed species. It ha s long beenrecogni zed that a bsolute size may not be auseful taxonomic criterion for mollu sca
species. It is only because that the ba sis of
the spiral models, namely, that mollu sca n
she ll s retain the same shape throughout
growth , ha s been accepted. In a group ofalli ed species, however, abso lute size at thesame growth stage is a useful ch a racter for thediscrimination of the allied species.
(c) Similarities and differences between
subgenera
The basic data used here comprise observations made on 15 species placed in 3 subgenera on the basis of Noda 's (1966) systematics.
These species a re classified practica lly into
two categories with respect to the ratio of thelength of the juvenile stage to the length ofthe completed adult she ll: one category of
species is repre se nted by TL(0) / TL(0.75) va lues less th a n 3 1%, and the othe r is represented
by va lues greater than 46%. Three species
placed in the subgenus Anadara (Anadara)
are classified into the lower value category:Osamu Sasaki

526

o

-

•

-

Figure 10. Ontogenetic and interspecific var iation of the shape of the commiss ure of Anadara(Hataiarca) subcrenata (Lischke) and its allied species. Symbols as in Figure I. 1 ; A. (H.) pseudosubcrenata Ogasawara from the Omma Formation in Ishikawa Prefecture. 2 ; A. (H.) subcrenata (Lischke)from the Narit a Formation in Chiba Prefecture. 3 ; A. (S.) cf. satowi (Dunker) from the Omma Formationin Ishikawa Prefecture.

a

b
0.5

"

I0.

"

>

0.5

0.2

o

0 .2

0.4

0.6

0.8

20

40

60

T L (mmJ

E VI PT@

A nadw'a ( /I a taiw'co ) pse udos ub c l'e l1ot a O gHS'l\Vl1 l';1o A nociw 'o (l-l atoiclI'ca) s ubcl'e nuta (Li sc hk e )+ Anocial'o (Scop h al 'co) cr . soto\\'i ( Dunk er)

Figure 11. a; Comparison between the relationships of the shape of the commissure (AT / TL) andgrowth stage (Ev / PT) for Anadara (Hataiarca) subcrenata (Lischke) and its allied species. b ; Compariso n between the relationships of growth stage (vE / PT) and abso lute size (TL) for the same species.

901.

Parameters Jor description oj genus Anadara

A. (A.) amicula elongata Noda, A. (A.)
hataii Noda, and A. (A.) hokkaidoensis
Noda. Five species placed in the subgenus
Anadara (Hataiarca), and 8 species placed in
the subgenus Anadara (Scapharca) areclassified into the higher value category: A.
(H.) kakehataensis Hatai and Nisiyama, A.
(H.) kogachiensis Noda, A. (H.) subcrenata(Lischke), A. (H.) pseudosubcrena ta Ogasawara, A. (S.) cf. satowi (Dunker), A. (S.)
ommaensis Otuka, A. (S.) shizuokaensis
Noda, A. (S.) taiwanica Noda, A. (S.)
makiyamai Hatai and Nisiyama, A. (S.)
ninohensis (Otuka), and A. (S.) tricenicosta(Nyst), as shown in Table 2. Therefore, thesubgenus Anadara can be discriminated fromthe other subgenera proposed by Noda (1966)
by using the value of TL(O)/TL(O.75).
Whereas, the subgenus Hataiarca can not be
discriminated from the subgenus Scapharca
by using this value.
The parameter TL(O)/TL(O.75), which
describes the nature of ontogenetic change inshell coiling, corresponds to the relationshipbetween Wand 0 in Raup and Michelson'smodel. Considering the change in the relationship between Wand 0 during ontogeny,
which is exhibited by gastropods and ammonites, relative increase in the distance from thecoiling axis to the generating curve (D) withrespect to the whorl expansion (W) makes theshell form more evolute and more umbilicate.
If the relationship changes during ontogeny
by logarithmic growth, the shell will become
more evolute as it grows. Therefore, thedifference in relative size [TL(O)/TL(O.75)J
between subgenera of the gen us A nadara canbe compared with the difference in degree towhich the shell becomes evolute as it grows;
lower value ofTL(O)/TL(O.75) will produce amore evolute shell.
In summary, the criteria useful for thediscrimination of taxonomic categories are as
follows:(I) Intraspecific variation: in a population placed in a single species, the relationships between descriptive parameters of shell527

growth (EV /PT, AT /TL, CH/TL and TL)
are defined; particularly, the EV /PT - TL
data are distributed in a narrow area of the
diagram. Intraspecific variation is found in
the relationship between the shape of thecommissure (AT /TL) and absolute size (TL).
(2) Interspecific variation between allied
species: allied species are similar in the relationship between the shell shape (AT /TL)
and the growth stage (EV /PT), but differ inthe relationship between the growth stage(EV /PT) and the absolute size (TL).
(3) Discrimination between subgenera of
the genus Anadara: Species placed in thesame subgenus are similar in the nature ofshell coiling represented by the relative size
[TL(O)/TL(O.75)J ; the relative size of
species in the subgenus Anadara is less than
31%, while that of species in the subgenera
Hataiarca and Scapharca is greater than
46%.

Discrimination of Anadara (Anadara)hataii and Anadara (Scapharca)
ninohensis

Anadara specimens from Kadonosawa in
Iwate Prefecture and Anadara specimensfrom Kubota in Fukushima Prefecture aredescribed by using the parameters defined
above, and the proposed criteria are applied
to discriminate their taxonomic categories.
(a) Review of the systematic problem
Anadara (Scapharca) ninohensis (Otuka)
was originally described from the lower
Middle Miocene Kadonosawa Formation by
Otuka (1934). According to the originaldescription, this species resembles Anadara
abdita (Makiyama, 1926) but differs by having ungrooved radial ribs; Anadara abdita
has a shallow median groove on each radialrib. Hatai and Nisiyama (1938) described
Anadara makiyamai based upon the specimen from the Heiroku Formation in Northern Korea by Makiyama (1926) as Arca
abdita.
Nomura and Hatai (1936) described the528

Osamu Sasaki

Anadara specimens from the middle Middle
Miocene Kubota Formation as Anadaraninohensis, and they pointed out that the
Kubota specimens have a great range of variation in shell ornamentation and in shell form.
N oda ( 1966) classified the specimens from the
Kubota Formation into three species: A.
(A.) ninohensis, A. (A.) tanaguraensis Noda,
and A. (A.) hataii Noda. Iwasaki (1970)
thought that the great range of variation of
the Kubota specimens was intraspecificphenotypic variation of the single species A.
ninohensis.
Despite this controversy over the systematic
status of the Kubota specimens, Iwasaki(1964) and Noda (1966) agreed that A. ninohensis was the common ancestor from which
the major Japanese Anadara lineages radiated. Iwasaki (1963) considered that A.
amicula and its allied species, which flourished during Miocene and Pliocene time
evolved from the A. ninohensis group, andthat they were the ancestral species of theliving A. subcrenata group. Noda (1966)
thought that A. ninohensis and its allied
species were placed in the subgenus Anadara,
which may have been the ancestors of two
major groups of subgenera Anadara thatflourished during Miocene and Pliocene
time: the A. (A.) tatunokuchiensis groupevolved from A. (A.) ninohensis, and the A.
(A.) amicula group from A. (A.) makiyamai.
(b) Observation on the specimens(b )-1 A nadara (Scapharca) ninohensis(Otuka)Stratigraphic records: Specimens of
Anadara ninohensis were collected from thetype locality of the Kadonosawa Formation
at a small branch of the Shiratori River in
Iwate Prefecture (Figure 12). The Kadonosawa Formation occupies the stratigraphically
middle part of the Shiratori Group in the
Ninohe area (Figure 13). The Shiratori
Group is divided into the Yotsuyaku, Kadonosawa and Suenomatsuyama Formations inascending order (Chinzei, 1966).
This group unconformably overlies the

+
140

•

Tanagura 0

HONSHU

Mito
142

Figure 12. Index map of localities of specimens
shown in Figures 14, 15. N inohe: A nadara (Scapharca) ninohensis Otuka. Tanagura: A nadara(Anadara) halaii Noda.

Ma

Tanagura

Ninohe5

10

Kubota F.

Akasaka F.

15

20

Figure 13. Stratigraphic occurrences of the
Kubota and Ninohe specimens. Black arrows indicate shell-bearing horizons.

90 1.

Parameters for description of genus Anadara

Nisata i Andesite. The diatom assemb lage
from the Kadonosawa Formation was correlated with the A ctinocyclus ingens Zone by
Maruyama (1984).
Synopsis: Shell medi um in size, thick andinflated. Left va lve sli ght ly larger than right.
Posterior margin slightl y shorter th a n anterior margin . Umbonal area we ll developed.
Bea k prosogyrate. Shell surface sc ulptu red
with 26- 30 (commonly 27 - 29) radial rib s.
Sur face of ribs finely undul ated by intersecting commargi ra l growth lin es on the left
valve, but ra ther smooth on the right va lve.
Shell morphology: Figure 14 shows theo ntogenetic var iat ion of this species. F igure
16a shows the CH - TL relationship for
Anadara (Scapha rca) ninohensis , a nd the529

EV / PT and TL data plotted as a scatter
diagra m a re shown in Figure 16b. These
diagram s show that the va lu e of T L is 20 mm
at the log size and 33 mm at an EV / PT va lu eof 0.75. The va lue of CH / TL is 0.1 at th elog size (EV / PT = O) a nd 0.152 a t the adu lt
size (EV / PT =0.75) . F ig ure 16c shows the
ontogenet ic c hange in the ratio of the anterior
and posterior teeth. The ratio is 0.32 at t helog size a nd 0.38 at the ad ult size.
(b) - 2 Anadara (Anadara) halaii Noda
Stratigraphic reco rds: Specimen s ofAnadara (Anadara) halaii were co ll ectedfrom the Kubota Formation at Han awa inFukushima PrefeCi.ure (Figure 12).
The Kubota Formatio n occupies the upper
part of the Higashi-Tanagura Gro up in the

o

-

-

Figure 14. Ontogenetic var iation of Anadara (Scapharca) ninohensis (Otuka) co ll ected from theK ado nosawa Formatio n in (wa te Prefecture. Symbol s as in Figure I.

Osamu Sasaki

530

Tanagura area (Figure 13). The Higashitanagura Group is divided into the Akasaka
and Kubota Formations in ascending order(Otuki , 1975). The geological age of the
Kubota Formation is 8- 12.5 Ma based on
microfossil data (Otuki and Kitamura , 1986).
Synopsis: This species has a wide range ofvariation in shell form. These variations areclassified into two variant types based on the
inflation of the shell and on the rib sculpture,
as follows :Type A: Shell large, very thick , and weaRly inflated. Shell surface scu lptu red with 2632 (commonly 27-30) radial ribs. Radialribs broad , flat-topped , and not subd ivided bya groove In you nger shells, but bipartite inmany adu lt shells. Beak sli ghtly prosogyrate, situated more anteriorly than that of TypeB. Type A corresponds to the intraspecificvariants Type I , Type 2 and Type 5 of lwasaki (1970). Also , the specimens that wereidentified as A. (A .) ninohensis by Noda
(1966) are identical with Type A.
Type B: Shell large, very thick , and stro ngly inflated in adult. Radial ribs 26- 32 (commonly 27 - 30). Ribs narrow, beaded - topped ,and bipa rtite in most shells, both young andadu lt. Type B corresponds to Type 3 andType 4 of Iwasaki (1970). The type specimen of A . (A.) hataii falls into Type B.

o

-

o

-0

Figure 15. Ontogenetic and interspecific variation of Anadara (Anadara) hataii Noda from the
Kubota Formation in Fukushima Prefecture. Symbols as in Figure 1. Specimens of the Type A va ri a nt are
shown in numbers 4 and 5; a spec imen of the Type B variant is sho wn in number 6.

•

90 I.

Parameters for description of genus A nadara

531

Shell /11olphology: Figure 15 shows the
ontogenetic and intraspecific variation of A.
(A.) hataii. Figure 16a shows the CH- TL
relation for A. (A.) hataii. The log size of
this species is TL = 15 mm. The EV jPT - TL
data, plotted as a scatter diagram, are shownin Figure 16b. At the adult size, the CHjTL
ratio is 0.066, and at the log size, the CHjTL
ratio IS 0.256. Figure 16c shows the
ontogenetic change in the ratio of the lengthof the anterior toothed portion to the lengthof the toothed portion of the hinge line. The
ratio has a value of 0.35 at the log size and amean value of 0.41 at the adult size. Variation in this ratio in adult shells is characteristic of this species. The proportion measured
in the intraspecific variant Type A is dis-tributed in the region of lower values (0.39),
and that of variant Type B, by contrast, isdistributed in the region of higher values(0.43).
(c) Discrimination of taxonomic categories
The Kubota specimens have a wide rangeof sheIl form. Because of this variation,
Noda (1966) classified the Kubota specimens
into three species, and Iwasaki (1970) recognized many intraspecific variant types. In
spite of this variation, almost alI specimens
have common properties of ontogenetic
change, as ilIustrated in the Figures. The
EV jPT - TL data for this population, especialIy, are distributed in a narrow area of the
diagram (Figure 16b), so that it is apparent
that alI the Kubota specimens belong in a

a

b

...a.
;:

0.5.

r-

UJ

o
o

20

40

o

60

20
T L Immj

d

C

0.5

0.6
0.5

-- - - - - - - --~ocp S? -~o-$- o:f'#J-~4a8-f5t'-..."...
<t 0.3
...J

60

40

T L (mm)

.0."

0.2

_:T

0.4

---

...

...J

+
_? __ . ____ . ___ . __________ _~<rt++~+
rPm__...<t 0.3"-.... ....
r-

0.2

+ +
I

0.1

o

I
40

20

r" }.
1

0

Cb~o~
00
0
COo +

cg+ '6 0c€ 0 0 + 0

+ a

08

+

0

0

0

t

0.1

o

60

TL (mmj

0.2

0.4

0.6

0.8

E VI P T+

Anadw'a (Scaphw'ca) n inohensis OtukaoAnadm'a (Anadm'a) hataii Noda

Figure 16. Comparison between Kadonosawa and Kubota specimens in ontogenetic change of shellform. a: Distribution of ontogenetic variation in the log CH-TL plane. b: Ontogenetic change in thearrangement of hinge teeth. c: Ontogenetic change in the ratio between the anterior and posterior hinge
lengths. d: Ontogenetic relationship between the values of AT /TL and EV /PT.

532

Osamu Sasaki

single species. The majority of the intraspecific variation of these specimens is foundas a wide distribution of the relationshipbetween AT jTL and TL, shown in Figure
16b. A similar type of variation can befound in A. (H.) subcrenata, as mentioned
above.
The descriptive parameters measured for
the Kadonosawa specimens [A. (S.) ninohensisJ and for the Kubota specimens [A. (A.)
hataiiJ are shown in Table 2. Comparisonof the relative size of these specimens makes it
clear that these specimens belong in different
subgenera: the Kadonosawa specimens havea high value of the relative size (63%), thus
they belong in either Anadara (Scapharca)
or Anadara (Hataiarca); whereas the
Kubota specimens have a lower value (30%),
and thus belong in the subgenus Anadara.
The subgenus Hataiarca was proposed by
N oda (1966), based on the morphologicalcharacter of a remarkably depressed area on
the posterior margin. Because the Kadonosawa specimens have no depressed area, they
can be placed only in the subgenus Scaphar-ca.
Otuka (1934) and many other workers
agreed that A nadara (Scapharca) ninohensis
is allied to A. (S.) makiyamai, which was
described from the lower Middle Miocene.
A. (S.) makiyamai has a high value of thelog size, as A. (S.) ninohensis has, and it has
no depressed area. By contrast, the species
allied to the Kubota specimens are A. (A.)
ogawai, A. (A.) watanabei, and A. (A.)
amicula, which constitute the Anadara amicula group of Iwasaki (1964). The Kubota
specimens and their allied species are assignable to the subgenus Anadara, which has low
values of the relative size. In the light of the
ontogenetic change in shell shape, theKadonosawa population of A. (S.) ninohensis has a remote relationship to the Kubota
population of A. (A.) hataii as the other A.
(S.) species have to A. (A.) species. The
phyletic relationship of the Japanese Anadara species, which was proposed by Iwasaki(1964) and N oda (1966), was constructed on
the assumption that the Kubota specimens
belong to A. (S.) ninohensis. The evidence
presented here shows that the phyletic relationships of Japanese Anadara species needreconsideration.

Conclusions
I : Ontogenetic variation in teeth characters and shell morphology occur in Anadara
species. Relational changes between teeth
characters and shell geometry are recognized;
tooth arrangement change (EV jPT) is related
to a change in the shape of the cardinal area
(CHjTL), and the ratio of the anterior andposterior hinge lengths (AT jTL) is related tothe proportion of the heights between theanterior and posterior commissural margins(AMjPM).
2: The shape of the Anadara shell can be
described dynamically by using sets of 5parameters: EV jPT, AT jTL, CHjTL,
TL(0)jTL(0.75) and TL. The EV jPT value
is a measure of the growth stage. The
ontogenetic change in the AT jTL value represents a change in the shape of the commissure. The change in the CHjTL value corresponds to the O-W relationship of Raup
(1966), which represents a change in shellinflation. The relative size [TL(O)jTL(0.75)J represents the ratio between thelengths of the juvenile and adult stages. TL
represents the absolute size of shell.
3: Taxonomic criteria for the discrimination of Anadara subgenera, groups of allied
species, and species are proposed based on
similarities in the ontogenetic change in shell
shape. Intraspecific variation is found in therelational change between AT jTL and TL.
Allied species are similar in the relationshipbetween EV jPT and AT jTL, but are
different in the relationship between EV jPT
and TL. The subgenus Anadara differsfrom the subgenera Scapharca and Hataiarcain the relative size [TL(0)jTL(0.75)J, which
represents the degree to which the shell901.

Parameters for description of genus Anadara

becomes evolute.
4: Anadara specimens from the Kadonosawa and Kubota were discriminated by using
the criteria proposed above, so that the specimens form the Kadonosawa are placed in thesubgenus Scapharca, and the specimens form
the Kubota are placed in the subgenus
Anadara. Therefore, the analysis of
ontogenetic change in shell form is a useful
method for the discrimination of Anadara
taxonomic categories.
The purpose of this paper has been toisolate some of the different elements
involved in the growth of the Anadara shell.
It has been suggested at several points that theuse of such an analysis may serve to reveal
similarities and differences that would be lesseasily recognized from more conventionalmodes of description.
In order to illustrate each factor in turnwithout complications, the analysis has been
concerned chiefly with shell form. Most
actual shells are the products of extremelycomplex interactions between many or all of
the features of surface ornamentation, internal structure and so on. The interactions
between them suggest that the ontogenetic
change in form cannot be ignored in systematic description and some attempts should bemade to describe the ontogenetic changes.
Since the shell is the cumulative product ofthese varied factors, its form should be described "dynamically", in such a way that thedescription emphasizes the sequence of stages
that brought the shell to its final form; and it
should be analyzed into its formally independent elements.
In the light of logic, the nested set structurethat taxonomic categories consist of represents logical relationships between the criteria
for the discrimination of these taxonomic
categories. This is an important reason why
the taxonomic categories should be represented by using the features of ontogenetic
change; the criterion used to definesubgenera expresses a more essential featureof similarities between shell shapes than the533

criterion used to define species expresses.
Acknowledgments

The author wishes to express deep gratitude
to Prof. Tamio Kotaka of Tohokugakuin
University for his supervision during thecourse of this study. Deep appreciation isdue to Prof. Kei Mori of Institute of Geology and Paleontology, Faculty of Science,
Tohoku University for his kind suggestions
and critical reading of the manuscript.
Acknowledgments are due to Prof. Hiroshi
Noda of Institute of Geoscience, the University of Tsukuba for his critical discussion on
taxonomic problems of the genus Anadara.
The author is most grateful to Assoc. Prof.
Kenshiro Ogasawara of Institute of Geology
and Paleontology, Faculty of Science, Tohoku University for his continuous guidance
and kind encouragement during the course ofthis study. Deep appreciation is due to Dr.
Alan G. Beu of New Zealand Geological
Survey for his kind suggestion and criticalreading of the manuscript.
For photographic work deep thanks are
due to Mr. Shohei Otomo of Institute ofGeology and Paleontology, Faculty of Science, Tohoku University. Thanks are expressed to the T. Katayama Memorial Scholarship for financial support.

References cited
Arkell, W.J., 1930: The generic position and phylogeny of some Jurassic Arcidae. Geol. Mag., vol.
67, no. 793, p. 297-310, pis. 14-16.
Chinzei, K., 1966: Younger Tertiary geology of theMabechi River Valley, Northeast Honshu, Japan.
Jour. Fac. Sci .. Univ. Tokyo. Sec. //, vol. 17, p.
161-208.
Iwasaki, Y., 1964: Notes on the historical changes of
the Japanese Teriary Anadara. Venus, vol. 22,
no. 4, p. 377-389. (in Japanese).
- - , 1970: The Shiobara-type molluscan fauna-an
ecological analysis of fossil molluscs. Jour.
Fac. Sci .. Univ. Tokyo. Sec. //, vol 17, p.351444, pis. 1-7.
Maruyama, T., 1984: Miocene diatom biostratigra-

Osamu Sasaki

534

phy of onshore sequences on the Pacific side ofNortheast Japan, with reference to DSDP Hole
438A (Part 2). Sci. Rep., Tohoku Univ., 2ndSer. (Geol.), vol. 55, no. I, p. 77-140, pis. 11-15.
Noda, H., 1966: The Cenozoic Arcidae of Japan.
Ibid., vol. 38, no. I, p. 1-161, pis. 1-14.
Nomura, S. and Hatai, K., 1936: Fossils from the
Tanagura Beds in the vicinity of the town
Tanagura, Fukushima-ken, Northeast Honshu,
Japan. Res. Bull., Saito Ho-on Kai Mus., vol.
10, p. 109-155, pis. 13-17.
Otuka, Y., 1934: Tertiary structures of the northwestern end of the Kitakami Mountainland, Iwate
Prefecture, Japan. Bull. Earthq. Res. Inst.,
Tokyo Imp. Univ., vol. 12, no, 3, p. 566-633, pis.
44-51.
Otuki, K., 1975: Geology of the Tanakura Shear
Zone and adjacent area. Contr., Tohoku Univ.,
Inst. Geol. Pal., vol. 76, p. 1-71. (in Japanesewith English abstract).
- - and Kitamura, N., 1986: Island arc transact
route No. 30 (Kawaji-Shiobara, Tanagura,
Jouban)-Geologic map, cross section and

HanawaJ?ij, Kadonosawar~O)tR,

Ninoheexplanatory text-. In, Kitamura, N. ed., Cenozoic Arc Terrane of Northeast Honshu, Japan.
vol. 3, Hobundo, Japan. 15 p. (in Japanese).
Owen, G., 1953: The shell in the Lamellibranchia.
Quart. Jour. Micros. Soc., vol. 94, p. 57-70.
Raup, G.M., 1966: Geometric analysis of shell coiling; general problems. Jour. Paleont., vol. 40,
no. 5, p. 1178-1190.
- - and Michelson, A., 1965: Theoretical morphology of the coiled shell. Science, vol. 147, p.
1294-1295.
Reinhart, P.W., 1943: Mesozoic and Cenozoic Arcidae from the Pacific Slope of North America.
Geol. Soc. Amer., Spec. Papers., no. 47, p. 1-117,
pis. 1-15
Rudwick, M.J.S., 1959: The growth and form ofbrachiopod shells. Geol. Mag., vol. 96, p. 1-24.
Stasek, C.R., 1963: Geometrical form and gnomonic
growth in bivalved Mollusca. Jour. Morph.,
vol. 112, p. 213-231.
Thompson, D.A.W., 1942: On growth and form.
Camb. Univ. Press, 1116p.

=.J5, Kubota~i*EH,

Tanagura

Wllf.

Anadara ~O)lP!:M~~;iffiO)t..:IlbO)IT~: lP!:~1I{0)1llt:llt~1r.a- 4 mO)f<$:~.lt* c ID!:-iT1;(O)I*l-l*c L1:MVTLt.:o ~nGO)Illt:llt~1r.a-*-tI*l-l*f1, Raup and Michelson (1965) t...
C'O)lP!:M~.'r-'E- T IvO)M~IT~fl3~O)I*l-l*t;::.~ U'o -t ~ -e, Noda (1966) t;::. J: -:> 1:~~~ nt.:5tm~t;::. ":)\, '1:, lP!:0)1llt:llt~1r.t;::. ":)\, '1: O)~~ c ffil'f.l a-~"". fiP-lm1bLfifl3', ~ 7.>\, 'f1l11!~fl3~t;::.:t-of't 7.>MJt~O)~~O)mn:na-, .'r-'E- T /H;::.;I;-::5\, '1::f:9l:W L t.:o -to)*6*iJ'
G, ID!:0)1llt:llt~1r.t;::.;I;-::5\,'1::lIE~, mibJ,fi, fit;::.5tm-t7.>t.:/JbO)~Ij~Ij;l;*a-~~Lt.:o ~n I? O)~IJ~U;l;*t;::.;I;-::5\' '1: Anadara ninohensis c ~ n -(I, ,t.: 2 ":)O)~*~BIl, r~O)tR~*~BIl c ~i*EH~*~BIlO)Illt:llt~1r.a-~U~1j L t.: *6~ n 1?00~*~BIlf1-t n.:fn~t... 7.>:lIE~K~-t7.>fic~~l?n7.>o

*.

~~*

~

Trans. Proc. Palaeont. Soc. Japan, N.S., No. 158, pp. 535-539, I Figs., June 30, 1990

902.

A NEW GENUS OF THE MIOGYPSINID FORAMINIFERAFROM SOUTHWEST JAPAN*
KUNITERU MATSUMARU
Department of Geology, Faculty of Education, Saitama
University, Urawa 338

Abstract. A new genus of the miogypsinid foraminifera, Tania is proposed from the
Miocene Miogypsina Sandstone of the Lower Formation, Bihoku Group, Okayama Prefecture. Tania inokosiensis, n. gen. and n. sp. is selected as the type species.
Key words. Tania inokoshiensis. Miogypsina Sandstone, Bihoku Group, Miocene,
Okayama Prefecture.

psina Sandstone at Inokoshi, which shows
peculiar characteristics intermediate between
the genera Miogypsinoides Yabe and Hanzawa (1928) and Miogypsina Sacco (1893) or
Lepidosemicyclina Rutten (1911). The
author should, therefore, like to propose a
new genus name Tania for these forms, taking
Tania inokoshiensis, n. sp. as the type species.

Introduction

Scince Yabe and Mabuchi (1934) described
Miogypsina cf. kotoi Hanzawa in addition to
Operculina cf. complanata Defrance from the
Miogypsina Sandstone, of the Lower Formation, Bihoku Group exposed at Inokoshi,
Koyamaichi Village, Okayama Prefecture,
our knowledge of Miogypsina from Inokoshi
has been extended by Hanzawa (1935), Tan(l937a), Ujiie (1966) and Matsumaru (1973).
Most specimens of Miogypsina from Inokoshi
are identical in every respect with those frommany localities of Japan, and have beenclassified as Miogypsina kotoi Hanzawa.
Miogypsina kotoi containing beds in the
Kanto Region, Central Japan was referred toN 8 Zone of the planktic foraminiferal Zoneof Blow (1969) by Matsumaru (1977), Takayanagi et al. (1978), Chiji and Konda(1978), and Matsumaru and Hayashi (1980),
hence the Miogypsina Sandstone exposed at
Inokoshi may safely be assigned to N 8 Zone,
which is considered to Early Miocene of Blow
(1969).
Recently, the present author discriminateda new type of Miogypsina from the Miogy-

Family Miogypsinidae Vaughan, 1928
Genus Tania Matsumaru, n. gen.

Type species: - Tania inokoshiensis Matsumaru, n. sp.
Diagnosis: - Test large, laterally flabelliform to somewhat digitate-form, longitudinally biconvex in outline, exterior surface
studded with large raised papillae directly
over periembryonic chambers and with small
ones arranged in apical portion; composedof layers of flattened lateral chambers on eachside of equatorial layer. Embryonic chambers of spherical protoconch and reniform
deuteroconch in megalospheric generation
apically placed, with no nepionic and equatorial chambers on place between protoconch
and marginal fringe of apical portion. Two
inequal sets of spiral nepionic chambers are
situated along the outer side of deuteroconch,'Received September 28, 1989; revised manuscript
accepted May 10, 1990
535

Kuniteru Matsumaru

536

which is always situated on place between
protoconch and normal equatorial chambersof frontal margin. Microspheric generation
with spire of nepionic chambers situatedapically. Adult equatorial chambers arearcuate, lozengic, hexagonal and spatulate;chambers connected by proximal and distal
foramina, and by a system of diagonal andconcentric stolons; intraseptal and spiralcanal system, and pillars present in central
portion of test.
Comparison: -This new genus resembles
Miogypsinoides in respect to the arrangementof embryonic chambers in the apical portionof test, but it can be distinguished from thelatter by having well-developed lateral chambers. Also, Tania resembles Miogypsina
without nepionic and equatorial chambers on
place between the embryonic chambers andapical fringe. However, the former is distinguished from the latter by both the arrangement of embryonic chambers in the apicalportion, and development of hexagonal tospatulate equatorial chambers. Tania resembles Lepidosemicyclina in having the hexagonal to spatulate equatorial chambers, but it isdistinguished from the latter by the arrangement of embryonic chambers. Miolepidocydina A. Silvestri (1907) and Miogypsinita
Drooger (1952) resemble Tania, but they are
distinguished from the latter by having normal nepionic and equatorial chambers on
place between the embryonic chambers andmarginal to apical fringe.
Etymology: - Tania is named in honor of
Tan Sin Hok, who introduced the nepionicacceleration theory of the miogypsinid foraminifera (Tan Sin Hok, 1936, 1937b) and isoriginated with his family name, Tan.

Tania inokoshiensis Matsumaru, n. sp.
Figures \-\-6

Type material: - Ho10type, equatorial
section, Saitama University Coil. no. 8803
(Figures 1-4,6); Paratype specimen, Saitama

University Coil. no. 8804 (Figure 1-1); Paratype, equatorial section, Saitama University
Coil. no. 8805 (Figures 1 - 2,3); Paratypes,
vertical section, Saitama University Coil. no.
8806 (Figure 1-5).
Description: -Test large in size measuring
2.3 to 2.5 mm., 2.3 to 2.8 mm. and 0.9 to 1.1
mm. in largest diameter, smallest diameterand thickness, respectively, from 12 specimens. Test usually ftabelliform (Figure 16), but sometimes with digitate-form (FigureI-I), and biconvex in vertical section (Figure1-5). Large raised papillae measuring from65 to 80 pm are distributed at thickest portion
over periembryonic chambers with respect toapical parts of test. Outer and inner diameters of protoconch being 268 to 313 pm and214 to 264 pm, respectively, from 4 specimens
in equatorial section. Outer and inner diameters of deuteroconch being 211 to 398 pm
and 170 to 313 pm, respectively, from 4 specimens. Proportion between protoconch anddeuteroconch diameters given 0.92 to 1.22 and1.10 to 1.23 in outer and inner diameters,
respectively. Angle (= y) between axis of
two embryonic chambers and apical frontal
line giving 135 to 140 degrees. Number ofprimary and secondary protoconchal nepionic chambers giving 5 to 6 and 3 to 4,
respectively, until both nepionic chambers
attaining to a stout wall on place between
protoconch and marginal fringe of apicalportion. Number of primary and secondary
deuteroconchal chambers and counting 1/2
for closing chamber are 2.5 to 3.5 and 2.5 to
4.5, respectively. Equatorial chambers inequatorial section arcuate to ogiva1, 10zengic,
and hexagonal to spatulate in shape, withdimensions of 108 X 67 pm to 135 X 102 pm,
122x135pm to 139X178pm, and 104 X 157
pm to 113 X 178 pm, respectively. Lateralchambers differentiated from equatorialchambers, arranged in 7 to 10 regular layers in
adult specimens. Lateral chambers withdimension of 82x47 pm to 129x65pm inwidth and height.
Locality: - Inokoshi, Koyamaichi Vil-

902.

New genliS of miogypsinid fo ram inifera

537

538

Kuniteru Matsumaru

lage, Kawakami-Gun, Okayama Prefecture(34°45'N. Lat., 133°24'E. Long.).
Stratigraphic horizon: - Miogypsina Sandstone, Lower Formation, Bihoku Group.
Geological age: - Early Miocene of Blow,( 1969).
Remarks: - Tania inokoshiensis, n. sp.
represents more primitive arrangement ofembryonic chambers and more advanced
hexagonal to spatulate equatorial chambers
than each one of Miogypsina kotoi Hanzawa,
respectively. The present new species H!presents the same hexagonal to spatulate equatorial chambers as Lepidosemicyclina thecidaeformis (Rutten) which has more advanced
equatorial chambers than Miogypsina kotoi.
However, this new species has more primitive
arrangement of embryonic chambers than L.
thecidaeformis. Also, Tania inokoshiensis,
n. sp. has the same arrangement of embryonicchambers as Miogypsina gunteri Cole fromthe Oligocene bed at Port St. Joe, Florida(Cole, 1938) that has its deuteroconch situated on place between the protoconch andmain equatorial chambers in frontal margin.
However, the latter is distinguished from theformer by the arrangement of nepionic chambers in a single spiral. Thus, Tania inokoshiensis, n. sp., whose arrangement of embryonic chambers is characterized in having
more than 135 degrees in y value, is considered to be more rationary close to Miogypsina
gunteri than to Lepidosemicyclina thecidaeformis.
In the Pacific Region, Miogypsina gun ted
Cole is found from the Late Oligocene to
Early Miocene Tagpochau Limestone at
Locality M 107, Saipan, Micronesia by Matsumaru (1976, pI. 4, figs. 1, 9). Also, thepresent author (in Hashimoto et al., 1977)

identified Miogypsina gunteri from the limestone of sample 11413 collected at aroundBugton Point, Mindoro, Philippines. This
limestone is known as the Early Miocene
Paclasan Limestone by Hashimoto and Matsumaru (1984, p. 158). Matsumaru (in Hashimoto et al., 1982, pI. 10, figs. 9, 10) described Miogypsina gunteri in association
with Nephrolepidina praetournoueri H.
Douville from limestone sample of the Escalante Formation at Locality 7682906, Negros, Philippines. Though Hashimoto et al.
(op. cit.) regarded this limestone sample to beprobably Early Miocene, the age of the limestone at Loc. 7682906 is thought probably tobe Late Oligocene, based on the occurrence ofNephrolepidina praetournoueri. As a resultof the present study, it is concluded that
Tania in okoshiensis , n. sp. may have a close
phylogenetic relationship to Miogypsina
gunteri, based on both the arrangement ofembryonic chambers and the relationship of
the occurrence between both species.
Acknowledgment
Appreciation is due to Professor Emeritus
Wataru Hashimoto, Tokyo University of
Education, for his kind discussion.

References cited
Blow, W.H., 1969: Late Middle Eocene to Recent
planktonic foraminiferal biostratigraphy. In,
Bronnimann, P. and Renz, H.H. eds., 1st.
Conf· on planktonic microfossils, Proc. (Geneva,1967), E.J. Brill, Leiden, p. 199-421, pis. 1-54.
Chiji, M. and Konda, I., 1978: Planktonic foraminiferal biostratigraphy of the Tomioka
Group and the Nishiyatsushiro and Shizukawa
Groups, Central Japan, with some considerations+- Figure 1. Tania inokoshiensis Matsumaru, n. gen. and n. sp. 1. Equatorial view of a paratype,
Saitama University ColI. no. 8804, X 30. 2-4,6. Equatorial sections, 2. X 37, paratype, Saitama University
ColI. no. 8805. 3, enlarged from 2, X 93, showing the arrangements of embryonic chambers, and nepionicand equatorial chambers in the apical portion. 4. Holotype, Saitama University Coil. no. 8803. enlarged
from 6, X 70, showing the arrangements of embryonic, nepionic and equatorial chambers. 6. X 23, showing
the whole test of the holotype with the hexagonal to spatulate equatorial chambers. 5. Vertical section,paratype, Saitama University ColI. no. 8806, x43.

902.

New genus of miogypsinid foraminifera

on the Kaburan Stage (Middle Miocene). Cenozoic Geology of Japan (Prof. N. Ikebe Memorial Volume), p. 73-92 (in Japanese with English
abstract).
Cole, W.S., 1938: Stratigraphy and micropaleontology of two deep wells in Florida. Florida Geol.
Survey Bull., voL 16, p. 1-73, pis. 1-12.
Drooger, C.W., 1952: Study of American Miogypsinidae. Univ. Utrecht, thethis, Zeist. Vonk. andCo., p. 1-80, pis. 1-3, 18 figs.
Hanzawa, S., 1935: Some fossil Operculina and
Miogypsina from Japan and their stratigraphicalsignificance. Sci. Rep., Tohoku Imp. Univ.,
2nd Ser. (Geol.), voL 18, no. I, p. 1-29, pis. 1-3.
Hashimoto, W. and Matsumaru, K., 1984: Mesozoic
and Cenozoic Larger Foraminifera of thePhilippines and a references to those found from
Borneo by the APRSA's palaeontological reconnaissance. Geol. Palaeont. Southeast Asia, voL
25, p. 147-166, I ta b.
- - , - - , and Alcantara, P.M., 1982: Larger Foraminifera from the Philippines. Part 8. Larger
Foraminifera from the Trankalan Limestone andthe Escalante (Toboso) Formation, west of
Lanao River Valley, northeastern Occidental
Negros. Ibid., voL 24, p. 31-38, pis. 10-11.
- - , - - , and Kurihara, K., 1977: Larger Foraminifera from the Philippines. Part 5. Larger
Foraminifera from the Cenozoic limestones in
the Mansalay vicinity, Oriental Mindoro, with anappendix" An Orbitoid-bearing limestone from
Barahid, Bongabong". Ibid., voL 18, p. 59-76,
pis. 8-9.
Matsumaru, K., 1973: Miocene larger foraminiferal
zonation in Japan. Mem. Geol. Soc. Japan, no.
8, p. 85-93, 4 figs.
- - , 1976: Larger Foraminifera from the islands ofSaipan and Guam, Micronesia. In, Takayanagi,
Y. and Saito, T eds., Progress in Micropaleontology, Micropaleontology Press Spec.
Pub., Amer. Mus. Nat. Hist., New York, p. 190213, pis. 1-6.
- - , 1977: Neogene stratigraphy of the northern tonortheastern marginal areas of the Kanto
Mountainland, Central Japan. Jour. Geol. Soc.
Japan, voL 83, no. 4, p.213-225 (in Japanesewith English abstract).

539- - , and Hayashi, A., 1980: Neogene stratigraphyof the eastern marginal areas of the Kanto
Mountains, Central Japan. Ibid., voL 86, no. 4,
p. 225-242 (in Japanese with English abstract).
Rutten, L.M.R., 1911: On Orbitoides of the Balikpapan Bay, east coast of Borneo. Proc. Konink.
Ned. Akad. Welensch., Amsterdam, p.11221131. 4 figs.
Sacco, F., 1893: Sur quelques Tinoporinae duMiocene de Turin. Bull. Soc. BeIge. Geol.
Paleont. Hydr., voL 7 (1893-1894), p. 204-207.
Silvestri, A., 1907: Probabile origine d'alcune Orbitoidine. Rivista ltaliana Paleont., voL 13, p.
79-81.
Takayanagi, Y., Sakai, T, Oda, M., Takayama, T,
Oriyama, J. and Kaneko, M., 1978: Problems
relating to the Kaburan Stage. Cenozoic Geology of Japan (Prof. N. Ikebe Memorial Volume), p. 93-111 (in Japanese with English
abstract).
Tan Sin Hok, 1936: Zur Kenntnis der Miogypsiniden. De Ing. Ned.-Indie, Mijnbouw., no.
3, p.45-61, pis. 1-2; no. 5, p. 84-98; no. 7, p.
109-123.
- - , 1937a: Note on Miogypsina kotoi Hanzawa.
Ibid., no. 2, p. 31-32, pL I.
- - , 1937b: Weitere Untersuchungen tiber die
Miogypsiniden I-II. Ibid., no. 3, p.33-45, pis.
1-3; no. 6, p. 87-111, pIs. 1-4.
Ujiie, H., 1966: "Evolutionary Line" of Miocene
Miogypsinid populations-Restudy of theJapanese Miogypsinids Part 2-. Bull. Nat.
Sci. Mus. Tokyo, voL 9, no. 3, p. 413-430, pIs. 16.

Vaughan, T.W., 1928: Subfamily Miogypsininae
Vaughan. In, Cushman, J.A. (1928): Foraminifera their classification and economic use.
Cushman Lab. Foram. Research, Spec. PubL no.
I, p. 354.
Yabe, H. and Hanzawa, S., 1928: Tertiary foraminiferous rocks of Taiwan (Formosa). Proc.
Imp. Acad. Japan, voL 4, no. 9, p. 533-536, 3
figs.
- - , and Mabuchi, S., 1934: Some observations in
Nariwa Region, Bittyu Province, Japan. Jour.
Geol. Soc. Japan, voL II, no. 487, p. 161-168 (inJapanese).

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Transactions and Proceedings of the PalaeontologicalSociety of Japan

June 30, 1990

New Series No. 158

CONTENTS
TRANSACTIONS
898. Tatsuro Matsumoto, Seiichi Toshimitsu and Yoshitaro Kawashita: On
Hauericeras de Grossouvre, 1894, a Cretaceous ammonite genus ......... .439
899. Ritsuo Nomura: Late Middle Miocene foraminifera from the Matsue Formation, Shimane Prefecture .............................................. 459
900.

Masayuki Noda and Seiichi Toshimitsu: Notes on a Cretaceous bivalve
Inocermus (Platyceramus) mantelli de Mercey from Japan ............... .485

901.

Osamu Sasaki: Parameters for description of the shell form of the genus
Anadara (Mollusca; Bivalvia) ........................................ 513
Kuniteru Matsumaru: A new genus of the miogypsinid foraminifer fromsouthwest Japan ...................................................... 535

902.