ISSN 0031-0204

Transactions and Proceedingsof thePalaeontological Society of Japan
New SeriesNo. 115

Palaeontological Society of Japan
September 30, 1979

Co-EditOTS
Associate editoT

Itaru HAYAMI and Tsunemasa SAITO
Tomowo OZAWA

Officers for 1979-1980

Honorary President : Teiichi KOB AYASHI
President:

Tetsuro HANAI

Councillors:

Kazuo ASAMA, Kiyotaka CHINZEI, Takashi HAMADA, Tetsuro HANAI,Haru HAY AMI, Hisayoshi IGO, Kametoshi KANMERA, Tamio KOTAK A, Tatsuro MATSUMOTO, Ikuwo OBATA, Tsunemasa SAITO, Tsugio SHUTO, Yokichi
TAKAYANAGI, Toshimasa TAN AI, Ryuzo TORIYAMA
Members of Standing Committee:

Kazuo ASAMA (Finance), Kiyotaka CHINZEI(General Aff airs), T akashi HAMADA (Planning), Itaru HAY AMI (Transactions),
Hisayoshi IGO (Foreign Affairs), Ikuw o OBATA (Membership), Tsunemasa
SAITO (Transactions), Tsugio SHUTO (Special Papers), Yokichi TAKAYANAGI("F ossils")
Secretaries:

Hiromichi HIRA NO and Yasumitsu KANIE (Membership), Kunihiro ISHI-ZAKI ("Fossils"), Tomowo OZAWA (Transactions), Toshiyuki YAMAGUCHI(General Affairs), Juichi YANAGIDA and Ienori FUJIYAMA (Special Papers)
Auditor:

Sumio SAKAGAMI

The fossil on the cover is Nipponitella explicata HANZA WA, an aberrant
uncoiled fusulinacean from the Lower Permian Sakamotozawa Formation,southern Kitakami, Northeast Japan.

A ll communications relating to this Journal should be addressed to the
PALAEONTOLOGICAL SOCIETY OF JAPAN,
c/ o Business Center for Academic Societies,
Yayoi 2-4-16, Bunkyo-ku, Tokyo 113, Japan.
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University of Tokyo Press, Hon g o 7-3-1, Tokyo, Japan.

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 115, pp. 109-134, pis. 16-18', Sept. 30, 1979

705. A LOWER MIOCENE ICHNOFAUNA OF THE MIDDLE
ASHIYA GROUP, NORTH KYUSHU-ICHNOLOGICAL STUDY OF THE ASHIYA GROUP-I*TSUGIO SHUTO
Department of Geology, Kyushu University, Fukuoka 812

and
SHIGEYOSHI SHIRAISHI
Kamitsushima High School, Kamitsushima 817-17

Abstract. Trace·fossils from the lower Sakamizu Formation of the Ashiya Group(Miocene) of North Kyushu, Japan, were investigated as a part of the paleoecological study of this group. Problems concerning the taxonomy of trace-fossils are
discussed briefly. Ophiomorpha ashiyaensis ichnosp. nov. and seven other tracetaxa are classified on the morphological basis and the builder organisms are considered to some extent. Furthermore, short notes on their occurrence and faunal
association are given in regard to the sedimento-ecological environments. Finally,a successional bathymetric change recorded in the lower Sakamizu Formation isdemonstrated.

investigated area besides the body fossils.
In some cases, trace-fossils are so abundant that the original physical sedimentary
structure and texture are quite disturbed.
Furthermore, an obvious tendency wasthat that part of the sequence aboundwith dense trace-fossils does not or rarely
yield body fossils. Accordingly, analysisof trace-fossils is indispensable for understanding ecological history throughout
the entire sequence of the Ashiya Groupin the Iwaya district. Hence, an ichnological investigation was done in 1976-78
in the same area as the malaco-ecologically studied one. Additional investigation was done in other parts of the
Ashiya Group and the uppermost part of
the Meinohama Group, which is strati-

I. Introduction

A paleontological research work of the
Miocene Ashiya Group was carried out
to establish a standard procedure for acommunity-paleoecological study in asmall peninsula of Iwaya and the adjacentarea, Kitakyushu City, Southwest Japan
in 1969-70 by the present authors. On
that occasion, the research work was
focused on the analysis of assemblagesof body fossils which consist almost exclusively of molluscs (SHUTO and SHIRAISHI, 1971).

A number of trace-fossils were foundat several horizons in the strata of the* Received March 8, 1979; read Oct. 16, 1977
at Kumamoto.
109

Tsugio SHUTO and Shigeyoshi SHIRAISHI

110

b
28C
280

o

LI2J
~

L...::..J

~

II

0

o

0

0

0

o

0

I~ ~ : I ill
a

100

m

Fig. 1. Geological sketch map of the Iwaya Peninsula, North Kyushu, Japan.
I: Recent beach sand. II: Intra· Wiirm dune sand. III: Intra· Wiirm Iwaya gravel. IV:
Ashiya Group; p, q, etc. being the alphabetical symbols of the beds examined and thenumerical figures being the important molluscan localites.

Ichnofauna of the middle Ashiya Groupgraphically equivalent to the Ashiya, toobtain data for comparison. Here thedescriptions of trace-fossils in question
are given in reference to ecological situations of the trace-builders. The resultof our biostratigraphical observation of
the trace-fossils throughout the entire
Ashiya Group will be given in a separate
paper.
II. Stratigraphical setting

The well-exposed Jinnoharu Sandstone
Member, the lowest of the Sakamizu
Formation of the Ashiya Group, is distributed in the investigated area with ageneral strike of N33-36W and eastward
dip of 17-20 degrees (Fig. 1). The strata
consist almost wholly of sandstones witha minor intercalation of siltstone (a-bed)
and calcareous muddy conglomerate (abed) and attain about a thickness of 120
m. The lithology of these sandstones
ranges from fine-grained to conglomeraticcoarse one and sorted, coarser medium _.
sandstones predominate over others.
Lateral change of lithology within asingle bed is slight so far as the studied
area is concerned. Besides the bedding
planes which define the upper and lower
boundaries of a bed, minor stratification
may be observed within a bed. Somebeds have cross-laminations or parallel
ones suggesting a high energy conditio.nat the time of deposition (rr, Or, nr, lr
bed, etc.) and some others show poorly
sorted muddy sand facies indicating a
relatively low energy condition (vr andurbed). The sorted medium sandstone
without lamination must have been deposited under a medium high energy
condition, which was rough enough tosort detrital grains but quiet enough topreserve organic sedimentary structures.
The definition of 32 beds, which weredistinguished from each other in our111

previous work according to their stratigraphic position and lithology along four
sections, is somewhat amended (Figs. 1
and 2). Sections 1, 2, 3 and 4 in Fig. 2
are located in the area ®'_~_@, @, @<D and ® in Fig. 1, respectively.
After NAGAO (1928) assigned the Ashiya
Group to the Middle Oligocene, several
conflicting views have been proposed
hitherto as to the age of this group(HATAI, 1938; HIRAYAMA, 1956; MIZUNO,1960 and KAMADA, 1967 and 1969). Adopting thestandard biostratigraphicalscheme of MIZUNO (1960), SHUTO (1978)
recently discussed the Neogene/Paleogene
boundary in North Kyushu. According
to his correlation, the Ashiya Group isincluded in the Miocene and the boundaryof the Lower/Middle Miocene lies in theupper part of the Sakamizu Formation.
III.
A.

Descriptions of trace-fossils

Taxonomy of trace-fossils

At the beginning of the present study,
the writers optimistically expected toclassify trace-fossils in relation to theirbuilder organisms under the scheme of
the International Code of Zoological
Nomenclature (STOLL et a!., 1964). However, it became evident in the course of
the study that the Code can not be
generally applied to the trace classification.
Observations of recent traces suggest,on one hand, that a single species may
produce a few different trace-structures
corresponding to the variability in its
behavioral and physiological activities
and that, on the other hand, organismsof unrelated taxa may make analogous
or identical structures. That is to say,anyone type of trace does not necessarily correspond to a single organism.
The case must be true with the ancient

TS'L~gio SHUTO an d Shi geyo shi SHIRAISHI

112

I
1-------:VI
UI-~;:.:.:.:-. &®@ @ =~ ~,,-=~@!

51

--l

....

. '

II

. .- J,.@@" .......

;."• .. :::;;;..... -

10 r;:;I
~

2EJ

11

3 r-::l12 W

L-J~~~c~ J;,,@

rl

ql

D

1=--==I®® I

18 1~ I26@]

1++ \ 27~
28 I @) I
20 0

194[] 13 m 21 10 I 291 <9 I
22 ~ 30G
5 ~ 14 0
OJ 23 0 31 [1]ITJ 24 1=\ 32 ~7 ~8D 17 ~ 25 \= I 33 CD

@C)=

J\.
A
AD

6_

. .Jk. 0@J (?) ~••••. A
'

15

16

98

ill

20m

i3

A

h3

A
1I

_

'-

~

=- -=

e3

A
A

o

IT

d3

d4

~

Jl,

0 =

@<@~

A
0(4
C4

0(3

b4

C3
'9",',<:;:::;>.

e1>?: -: .

b3

a3
A3

.

..-

B3

.:... . ~C3Jl, ~~-;,-t

a4

..L

0<9

A4

J1.

~

!

O ~==.@:>
Jl~ o@)@

..L-

O~ ~

..L-

A ~®

..L

A~~e

A=@O~
cz,
@)

A
J\,o
J\,c:::>oIchnofauna of the middle Ashiya Group113

Table 1. Occurrence of the crustacean body fossil in a burrowof Ophiomorpha or Thalassinoides(1941)(1944)
FIEGE (1944)
GLAESSNER (1946)
WAAGE (1968)
SHIN (1968)
SELLWOOD (1971)
MERTINEHRENBERG

Protocallianassa in Thalassinoides
Callianassa in Thalassinoides
Glypheoid in Thalassinoides
Callianassa major in Thalassinoides
Callianassa in Ophiomorphaa shrimp in Thalassinoides
Glyphea udressieri in Thalassinoides

trace-fossils as has been demonstrated
by the correspondence of the trilobite to
Rusophycus (resting trace), Cruziana(grazing trace) and Diplichnites (walking
trace) and by the occurrence of a bodyfossil of Protocallianassa, Callianassa or
Glyphea in a trace-fossil of Thalassinoides (Table 1). A great difficulty inthe biological classification of trace-fossils
lies upon this fact. Several authors have
tried to overcome this difficulty and to
manage the taxonomy of trace-fossils.
OSGOOD (1970) pointed out a lack ofclean guide line in the International Codeof Zoological Nomenclature (Op. Cit.) forthe classification of trace-fossils andmaintained that body fossils and tracefossils should have respective genericand specific names. HANTZSCHEL and
KRAUS (1972) discussed the nomenclatureof ichnofossils in line with OSGOOD and

Up. Cret., Germany
Mio., Austria
Mid. Trias., Germany
Eo., Australia
Up. Cret., N. America
Cret., N. America
Mid. Jura., Englandproposed further that the names ofichnotaxa be printed in different way
from those of body fossils. SARJEANT
and KENNEDY (1973) gave a comprehensive discussion on the taxonomical problem of trace-fossils and proposed a "Codefor the Nomenclature of Trace-fossils".
The present authors have the same
opinions in many respects as SARJEANT
and KENNEDY. Firstly they share theopinion that trace-fossils would inevitably
be recognized as form taxa under thepresent, poor state of knowledge on bothfossil and recent traces, because the strict
adherence to the biological taxonomy inclassifying trace-fossils would certainly
provoke a confusion. This does not meanthat the classification of trace-fossils
should remain a pure form-taxonomy. A
passage way is always kept to link eachform-taxon of the trace to builder or-

Fig. 2. Columnar sections of the middle Ashiya Group in the Iwaya Peninsula.
The columns I, II, III and IV are respectively observed in the areas @-@-@', ®, ®-<Dand ® in Fig. 1. Beds in the columns I, II, III and IV are made distinctive in the text byuse of suffix 1, 2, 3 or 4 (ex. a2, aa and a4)'
1: conglomerate, 2: lens of granule, 3: patches of coarse sand, 4: medium sandstone,
5: muddy sandstone, 6: siltstone, 7: cross and parallel laminations, 8: calcareous nodules,
9: Glycymeris bed, 10: pellet mound (circular) and washed pellet-sheet (elliptical), 11:
onion structure, 12: Ophiomorpha ashiyaensis, 13: Thalassinoides iwayaensis, 14: T.
giganteus, 15: Cylindrichnus japonicus, concentric form, 16: C. japonicus, eccentric form,
17: Tosalorbis ? ichnosp., 18: Nankaites kochiensis, 19: Unarites ? ichnosp., 20: Acila
ashiyaensis, 21: Glycymeris cisshuensis, 22: Venericardia subnipponica, 23: Lucinoma
nagaoi, 24: Cultellus izumoensis, 25: Solen connectens, 26: Angulus maximus, 27: Dosinia
chikuzenensis, 28: Pitar ashiyaensis, 29: P. matsumotoi, 30: Diloma (Oxystele) sp., 31:
Turritella (Hataiella) spp., 32: Euspira ashiyaensis, 33: other gastropods.
As to the molluscan faunae, only dominant species are illustrated in this figure.

114

Tsugio SHUTO and Shigeyoshi SHIRAISHI

ganism. Correspondence of trace-fossils
and builder organisms may be made clear
in future at the generic level in manycases, but it is expected possible at
species level in only a few exceptional
cases. And even a trace-taxon may correspond with two or more genera oforganisms. In consequence, the tracetaxonomy can not be quite dissolved in
the animal taxonomy and it must necessarily have an independent system. The
form-taxonomy may be a system to meet
the above requirement. It is really independent from the biological taxonomy,
but its methodological procedures mustnot be quite different from the ICZN
except for the inevitably emended parts.
When pure form-taxa are adopted in
the trace-taxonomy, a perplexed tendency
may be inevitable to split taxa and to
give independently different names torespective parts of a single structure.
Therefore, the following principle is necessary to avoid confusion that an
ichnotaxon should be established bymorphological data not on any part of asingle trace system or structure, but on
a whole system. Under this principle,
priority in nomenclature may be called
in question, when there are an older andan younger names respectively based ona part and on the whole structure.
Priority, of course, should be greatly
respected in the nomenclature in general.
However, a rule should be claimed thata name based on a whole system or, atleast, on an ubiquitous feature has
priority as against a name based on arare feature or a part of the same system(efr. Ophiomorpha LUNDGREN, 1891 andGyrolithes De SAPORTA, 1884; see p. 116).
Form-taxonomy may not necessarily be
the best method, but is, at least, themost practical solution to deal withtrace-fossils. Yet, one should keep thebasic fact in his mind that a trace wasmade by a certain behavioral or physiological activity of an organism. Thus,
certain ichnotaxa which were establishedon the morphological basis must be integrated with one another to cover amore general feature of a trace structureby having another-looks from this standpoint. Through this procedure, the morphological feature of a trace system becomes clearer and, in consequence, theethological consideration of the trace
becomes easier. For example, Ophimorphachiefly consists of shafts and tunnels,
but is associated in some occasions witha spiral shaft (Gyrolithes), pellet-mounds
and/or faecal pellets, etc. They may benaturally named separately in the earlystage of research, but should be unified
under a single name, Ophiomorpha, after
enough data are accumulated. This rule
is concordant with the above noted ourbasic view about the taxonomy of tracefossils.
Recognition of the holotype of a tracetaxon is the second difficult problem
under the above principle. Whole partsof a single trace system, particularly
large and branching one in a consolidated
rock, can not always be excavated andeven observed because of its three dimensional nature. Accordingly, a taxon can
not always be established on the basisof a good specimen which is suitable fora "holotype", but is described synthetically by numberless observations of partsof individual structures. How can one
designate the holotype in this case? Free
specimens in hand, in this case, represent
more or less partial structures. Accordingly, any of them can not be selected
as the holotype without objection. Hence,
it may be a solution of the problem todesignate the holotype on the basis of aphotograph of unexcavated specimen as
AGER (in SARJEANT and KENNEDY, 1973)
advocated, when any of the specimens

Ichnofauna of the middle Ashiya Group
exposes nearly whole structure or anubiquitous feature of the structure. However, a completely exposed specimen ishardly expected in case of a large andcomplicated trace-structure such as Ophiomorpha and Thalassinoides in consolidated rocks. Holotype designation on
the basis of the photograph is therefore
discarded. Then, from a practical pointof view, it is advisable to accept a specimen representing more important or
ubiquitous structure as a holotype and aset of specimens, which respectively represent another part of one structure, as
paratypes. The last mentioned procedure
is adopted in this paper, although thepara type is not formally adopted in theInternational Code of Zoological Nomenclature. The traces selected as types
were photographed before excavation.
In printing names of ichnotaxa, thepresent authors prefer to adopt romanletters to distinguish them from the taxa
named in accordance with ICZN.
A synthesis of a general picture of a
trace system from numberless observations of various parts of three dimensionally stretching structures tends to be
influenced by a subjective judgement.
To minimize subjective judgement, thequadrat-observation-method was employed in this study. A quadrat, 1 m xl m,
was set on cliff-walls, eroded out stratification planes or bench-cut planes.
Relative position of any quadrat in the
bed was checked at first and then tracefossils in the quadrat were measured andsketched in detail. A care was particularly given to measure vertical andoblique shafts and horizontal tunnels ofsuch burrow systems as Ophiomorpha andThalassinoides to calculate a shaft/tunnel
ratio, which serves for the recognitionof an average configuration of a standard
burrow system (Fig. 4 and Table 2).
All the observed trace-fossils are com-115

plete structures in the sense of SCHAFER,(1962).
Whether or not grouping of ichnotaxa
into any category above the generic levelis useful is a matter of dispute. While
several kinds of grouping and orderingof ichnotaxonomic categories have been
proposed hitherto, SARJEANT and KENNEDY (1973) regarded the grouping meaningless. From a practical point of view,
the present authors consider that an appropriately selected grouping is a great
aid for an easy identification of any
newly obtained material of trace-fossils.
One may be able to search more easily
for a taxon identical to or comparablewith a newly obtained material when ahigher category comprising many similar
forms is available, rather than going
through an unordered pile of numberlessgenera and species. Here, the present
authors adopted VIALOV'S classification(1972), although it is not necessarily
satisfactory. Particularly, a weakness
lies in an indefinite relation between
Cryptoreptida of Fossiglyphia and Apodichnaea of Bioexoglyphia. Furthermore,
the latter seems to cover too many
divergent forms. However, his classification may possibly be improved with minor
emendation.
Following is the systematic list of
the trace-fossils from the Middle Ashiya
Group.
Vivichnia
Invertebratichnia
Bioendoglyphia
Fossiglyphia
Endotubida
Crustolithidalarge and complicately branching.
(i) wall with granular ornamentation .................. type A,
Ophiomorpha ashiyaensis
ichnosp. nov.
(ii) wall without ornament

116

Tsugio SHUTO and Shigeyoshi SHIRAISHI(0:) moderately large .. type B,

Thalassinoides
iwayaensis ichnosp. nov.
((3) very large with polygonaltunnel ............ type C,
Thalassinoides giganteus
ichnosp. nov.
Rectotubae( i) vertically stretching: wall
thick, mucus-coated and multilayered; surface smooth.
(0:) short (less than 10 cm),
opening concentric to theouter wall ........ type D,
Cylindrichnus japonicus
ichnosp. nov. concentric
form((3) long (longer than 10 cm),
opening eccentric to theouter wall ........ type E,
Cylindrichnus japonicus
ichnosp. nov. eccentric
form(ii) horizontally and obliquely
stretching; wall with septal
structure .............. type F,
Tosalorbis? ichnosp.
Cryptoreptida(i) string-like, very small, nearlystraight or curved, rarely ramified; surface smooth .. type G,
Nankaites
kochiensis
KATTO(ii) moderately
small,
nearlystraight or curved, rarely withthorn-like ramification; surface
uneven ................ type H,
Unarites? ichnosp.
B.

Descriptions of species

Ichnogenus Ophiomorpha LUNDGREN, 1891
type-species: O. nodosa LUNDGREN(Mono type)
HANTZSCHEL (1952 and 1975) listed thesynonyms of Ophiomorpha as follow;
Astrophora DEECKE, 1895; Sabellastartites
DUDICH, 1962; Cylindrites GOPPERT, 1842
(partim, C. spongioides) nom. nud; Halymenites STERNBERG, 1821 (partim, H.
major and ?H. ftexuosus); Spongites
GEINITZ, 1842 (partim, S. saxonicus).
While KENNEDY (1967) regarded Gyrolithes DE SAPORT A, 1884, Thalassinoides
EHRENDERG, 1844 and Ophiomorpha LUNDGREN, 1891 as synonyms, BROMLEY andFREY (1974) claimed to treat those burrows and Spongeliomorpha DE SAPORTA(1887) as separate taxa. A vertical spiraltunnel, Gyrolithes DE SAPORTA, 1884, wasreported as a part of Ophiomorpha borneensis KEIJ from the Upper Miocene Belait
Formation of Southwest Saba (KEIJ, 1965)
and a similar association of Ophiomorphanodosa L. and Xenohelix dr. X. marylandica MANSFIELD (=Gyrolithes) was
described by KILPPER (1962) from the
Miocene of Germany. These facts strongly suggest a synonymous relation of
Ophiomorpha with Gyrolithes. If this is
the case, Gyrolithes should be rejected
because it is neither founded on a generalburrow system nor an ubiquitous featureof the· burrow system, although Gyrolithes
is a senior synonym to Ophiomorpha.
KENNEDY (1967) described four ichnospecies under the ichnogenus Thalassinoides from the Lower Chalk of southern England. The four species show
a granular, reticulate, scratch-marked
and smooth texture of the wall-surface,respectively. That is to say, he did notrecognize any distinction between Ophiomorpha and Thalassinoides. The joint
occurrence of body fossil of Callianassa
and ichnogenus Ophiomorpha or Thalassinoides (EHRENBERG, 1938; WAAGE, 1968;
and GLAESSNER, 1946) seems to support
KENNEDY'S view. However, the joint occurrence of Ophiomorpha or Thalassinoides with crustacean genera otherIchnofauna of the middle Ashiya Group
than Callianassa (Table 1) makes the problem complicated. Later, KENNEDY and
MACDoUGALL (1969) concerned to use
Ophiomorpha and described three typesof O. nodosa from the Lower Cretaceous
Weald Clay of southeastern England.
One is provided with the typical knobby
ornament, the second with a scratchmark and the third with a meniscus
a-bed

F.'l

A~

B~

cklJ

DU

0--20 emFig. 3. Bioturbation by Ophiomorphaashiyaensis ichnosp. nov. in the n·bed.
A: granule, B: obviously tainted por·tion with organic secretion, C: obscurely
affected portion by organic material,
D: original laminae in the sediment.

+ :~:::.~.'.'.'.'.'."'.'."'.':'."
ABC

0

DD~1ilI

Fig. 4. Two burrows of Ophiomorphaashiyaensis ichnosp. nov. in the f·bed on a
vertical cliff.
A: granule, B: obscurely affected por·tion by organic material, C: obviously
tainted portion by organic secretion, D:
granular wall of burrows.

117

structure. The present authors prefer toadopt Ophiomorpha and Thalassinoides
as valid names applicable respectively
for a large and branched burrow systemwith knobby ornament on the wall andfor those others with a smooth wall.
Ophiomorpha ashiyaensis ichnosp. nov.
(Crustolithida, type A)
PI. 16, Figs. 3 and 4, PI. 17, Figs. 1, 2
and 8, PI. 18, Figs. 1 and 2,
Text-figs. 3, 4 and 5B and C.

Holotype: GK-L 8725a and Paratypes
GK-L 8725 band c from the o,-bed.
Diagnosis: Large and complicately
branched burrow system attaining morethan 100 cm deep and consisting mainlyof shafts, tunnels and turn-around globes
and normally associated with pelletsmound. Wall of shaft and tunnel being
provided with granular ornamentation.
Morphology: Burrows of the type A
extend downward from pleural openings
on an omission plane to a depth of 70170 cm and its lateral extension attains
a maximum length of 117 cm. It has
distinct mounds consisting of ovoidalpellets. Pellets are usually as large as arice grain, but are seldom 7-8 mm indiameter. In some cases mounds aredenuded and pellets are scattered in thinfilm over two meters from the original
mounds. It has not been made clear how
many pleural openings a single burrow system have, but some of the observed burrow systems are apparently
provided with two or three openings.
Shafts, extending from pleural openings,
converge one after another at some depth.
Once converged, the shaft mayor may
not branch off along the downward
course. Horizontal tunnels radiate fromthe vertical shaft and branch out in acomplicated zigzag, dendroid or Y -shaped

118

Tsugio SHU TO and Shigeyoshi SHIRAISHI

fashion. Shaft is round in transverse
section with a diameter of 2.0-2.5 cm andrarely of about 1.0 cm. There may be or
may not be a globe at the point of branching. A shaft between the neighbouring

ramifications is generally straight, but
may be curved in some instances. Branching angle may be acute or obtuse. Shafts
and tunnels have walls of 2-3 mm thick,which are lined with mud and probably

Table 2. Frequency of shafts and tunnels of Ophiomorpha ashiyaensis ichnosp. nov. and Thalassinoids iwayaensis ichnosp. nov. on a
stratification plane (S in orientation), steeply inclined cliff (V) or
wave·cut horizontal bench (B).
Frequency is represented by observed counts in a quadrat, 1m x 1m.
Sum of the measured length of the exposed tunnels is also indicated.
To indicate the relative position of a quadrat in a bed, a square (steeply
inclined cliff), oblique bar (bench) and horizontal bar (stratification
plane) are employed.
Ophiomorpha ashiyaensis
locality
f 1-l
quadratnumber (Q)10orientation
V
shaft
vert.
67
obI.
27
tunnel25hor.
length (em)position inU
the bedlocalityPl-lquadratnumber (Q)1orientation
B
shaft
vert.
80
obI.
17
tunnelhor.
62
length (em) 585
position in
the bed-f l -2f l -3

k1-l

kl -2

n1-l

nl -2

0 1-1

4

2

3
B

S

1
V

4

B

2
V

1

B

54
12

3
0

48
12

27
11

14
0

12
5

41
6

34
685

-

0

26
470

6
85

20

100
2580

13

-

-

- --

0

Pl- 2

r 1-l

r l -2r l -3

1
S

2

1

1

1

1

V

S

S

S

S

31
0

15
4

18
7

112
4

19
3

33
3

0

7

6
125

3
70

15
285

6
85

-

-

0

sl-l

sl- 2

U

--

u1-l

v1-1

vl -2

vl -3

vl -4

2

2
V

2

2

B

4
V

2

S

B

B

63
2

42
19

26
8

139
10

191
14

29
10

2
15

89

14
210

71
710

-

Thalassinoides iwayaensis
localityt 1-1
quadratnumber2
orientation
B
shaft
vert.
159
obI.
20
tunnelhor.
19
lengtJ- (em) 165
position in
the bed

- -

-

-

6

11
49

n

0

-

vl -5

- -

B

-

Ichnofauna of the middle Ashiya Group
mucus. The texture of a wall is granularon the outer surface but is seemingly
smooth inside. Pellets of about 3 mm indiameter are coarsely packed on the wallwith a random orientation. Owing to
the wall-structure mentioned above, theshaft and tunnel are readily distinguishedfrom the surrounding sediment by a sharpboundary. It must owe to this reinforcement that both shaft and tunnel do notshow any sign of collapse by the loadof sediments except for the terminal
part of a horizon tally stretching tunnel.
Some shaft have broad cells with a diameter of 5 cm and length of 15 cm, which
are bordered by a constriction.
Comparison.' Ophiomorpha LUNDGREN,
1891, consists of shafts and tunnels andis rather large attaining the depth of 3090 cm and diameter of 0.95-2.5 cm. It isprovided with a knob-like texture on theouter surface of walls and mud lining
inside. It shows various patterns ofbranching and has often a globe at the
point of branching. The type A burrow
is asigned to Ophiomorpha on the basisof the morphology as described above
and named O. ashiyaensis. The observed
morphology of the examples from theMiddle Ashiya Group conforms well withthose described by FREY, HOWARD and
PRYOR (1978).
Ophiomorpha ashiyaensis apparently
includes two types. One is typicallyfound in clean, coarser medium sandstones and is characterized by a longer
shaft and less well-developed horizontal
tunnels. The other abundantly occurs inless sorted and less stratified sandstones
and is featured by a more complicatedtunnel system. It is not clear whether
the difference in the burrow system isrelated to an intraspecific ecologicaldivergence or to the taxonomic differenceof the builders.
Body fossil ever found in the Ophi-

119

Fig. 5. Plan of horizontal tunnels.
A: Thalassinoides giganteus ichnosp. nov.
Band C: Ophiomorpha ashiyaensis ichnosp.
nov.

omorpha burrows is Callianassa as indicated in the Table 2. Ophiomorphafrom the Middle Ashiya Group is alsosimilar to the burrow of living Callianassa
and the former is most probably attributed to an ancient Callianassa. Thalassinidae
including Callianassa, Upogebia, Alpheus
etc. is one of the most extensively investigated groups of Recent trace builders.
Ophiomorpha major (LESQUEREUX),
which has long been regarded as an algal
structure, has a geological range from
Recent back to the Cretaceous in central
and southeastern U. S. A. and its builder
was referred to Callianassa major SAY(HoYT and WEIMER, 1963). POHL (1956) and
WEIMER and HOYT (1964) mentioned of
the small upper part of the shaft of theburrow of C. major with a diameter of
5-10 mm and length of 10-20 cm. The
following parts, although their descriptions do not necessarily agree with eachother, become gradually larger downward
to a diameter of 20 mm and have several
branches. Its vertical extension is 90180 cm. O. ashiyaensis is similar in size
to the burrow of Callianassa major SAY
described by these authors, but does notreveal a gradual increase in the diameterof shaft in the second segment. Moreover, O. ashiyaensis has more finely knob-

120

Tsugio SHUTO and Shigeyoshi SHIRAISHI

by wall.
WEIMER and HOYT (1964) and FREY
et al. (1978) referred the North American Upper Cretaceous species of Ophiomorpha to O. nodosa L. However, theNorth American species are clearly distinguishable from O. nodosa in the walltexture. While O. nodosa has ovoidalpellets whose long axes are arranged
perpendicularly to the direction of shaft,the North American "0. nodosa" showsa single-pellet wall construction. The
latter actually belongs to O. major.
Ophiomorpha nodosa L. ranging fromthe Jurassic to the Miocene in Europe,
consists mainly of shafts and has few
tunnels. In this feature, the present ichnospecies from the offshore-bar facies issimilar to O. nodosa, but is readily distinguished from the latter by the walltexture as mentioned above.
Ophiomorpha borneensis KElJ from theUpper Miocene Belait Formation ofLabuan, Southwest Saba, has a similar
burrow system to the present species withmany horizontal tunnels. The former is,
however, distinguished from the latter inhaving cocoon-like pellets with double
cones.
HATAI et al. (1968 and 1970) reportedpellet mounds from the Pliocene Kogota
Formation, Miyagi Prefecture, Japan.
The pellets, in this case, are somewhat
cylindrical, gently curved, and are readily
distinguishable from the ovoidal pelletsof the present species.
Occurrence: Ophiomorpha ashiyaensis
is typically yielded in well-sorted coarser
medium sandstone with parallel lamination (n,-, lower p,-, r,- and s,-bed) which
laterally grades into a cross-laminatedsandstone. Both of these sandstones represent an offshore-bar facies. It also
commonly occurs in a well sorted massive
sandstone (A-, f,- and upper n,-bed).
Bioturbation by this ichnospecies is morevigorous in some of less sorted medium
sandstones with finer component (b-, d,-,i,-, k,-, 0,- and upper p,-bed). Finersandstones (h,- and j,-bed) sporadicallycontains traces of this ichnospecies. It
rarely exists in coarse sandstones, evenin conglomeratic sandstone (g,-bed) andsilty sandstone (top of p,-bed). Burrows
often cross the intrastratal stratification
but do not penetrate interstratal bedding
planes. Sometimes, they remarkably disturb the original sedimentary structureand show an obvious tendency to form
calcareous nodular lenses and layers.
Burrows of this type are more densely
distributed in the area @-@ than in ®.
In a single bed, shafts occur much more
densely than tunnels in the upper 50 cm
below the omission plane and a reverse
relation is observed near the lower
boundary plane. The ratio of the numberof shafts and tunnels is nearly 2: 1 onan erosion plane parallel to the bedding
at the middle part of all the examined
beds (Table 2).
Pellets associated with O. ashiyaensis
show two types of occurrence. One is apellet-mound which keeps the originalform (d,-, h,-, i,-, k,- and o,-bed) and theother is a spread sheet (e,-, m,- and n,bed). The former indicates a rather quiet
environment below the tidal zone, while
the latter reveals a weak winnowing action of water. Under a higher energetic
condition, pellet mound would be utterly
destroyed and did not leave any sign oforiginal mound nor secondary sheet.
The last case is exhibited by the association of Glycymeris cisshuensis and O.
ashiyaensis in the p,-bed, in which
Glycymeris forms a shell layer suggestiveof a rough sea condition by hydrostableorientation of its heavy valves.
Ophiomorpha ashiyaensis shows thewidest variety of species association,
which is simply defined here as the co-Ichnofauna of the middle Ashiya Groul)
occurrence of both ichno- and biospecies
at a single horizon of any locality.
Although the present ichnospecies is not
associated with any other fossil in theoffshore-bar facies, it occurs frequently
together with the type D in less sorted
and finer sandstones. This association
may be accompanied with the type F, G,
H or a molluscan assemblage of Angulus
maximus-Pitar ashiyaensis-Lucinoma nagaoi. While O. ashiyaensis occurs in acoarse sandstone together with Glycymeris
cisshuensis, Lucinoma nagaoi and Pitar
matsumotoi (PI-bed), it is associated in asilty sandstone with Phaxas izumoensis
and Angulus maximus (cr, c4 - and d.-bed).
The most diversified association consisting of Ophiomorpha ashiyaensis, the type
F, D, E and H is seen in a silty sandstone of the uppermost PI-bed.
Ophiomorpha has been regarded as agood indicator of both the shallow sublittoral and littoral facies (PATTERSON,
1942 ; HOYT and WEIMER, 1963 ; KEI], 1968 ;WAAGE, 1968; and DIKE, 1972), althoughrare examples are known from a nonmarine (Middle Eocene Helmstedt Lignite
Formation, HILLMER, 1963) and deeper
marine facies (upper part of the glauconite-forming zone, DIKE, 1972). The
present example well agrees with thetypical occurrence with rare exception.
That is to say, the builder of O.
ashiyaensis generally had its habitat in
the submerged part of offshore-mound(OB type burrows) and lower foreshore(FS type burrows). The FS type burrows
occasionally extends to a deeper zone,
i. e. sublittoral zone with substrate of
muddy sand. LUTZE (1938) mentionedthat the North Sea and Mediterranean
species of Callianassa have their habitats
in the middle to lower sublittoral zone
and uppermost sublittoral zone, respectively. This suggests a tendency of bathymetric gradation of Callianassa according121

to aquatic climate. If this tendency is a
general rule, and the builder of Ophiomorpha ashiyaensis was Callianassa
species, its habitats might have been
covered by a warm water.
Ichnogenus Thalassinoides
EHRENBERG, 1944
type-species: T. callianassae
EHRENBERG, (0. d.)Thalassinoides iwayaensis ichnosp. nov.
(Crustolithida,. type B)
PI. 16, Fig. 6 and PI. 17, Figs. 3-7 and 9.

Holotype: GK-L 8731a and para type
GK-L 8731b from the trbed.
Diagnosis: Large and com plicately
branched burrow system attaining morethan 100cm deep and consisting of shafts,
tunnels and globes. Wall of shaft andtunnel smooth.
Morphology: The burrow consists ofshafts, globes and tunnels and attains
more than 100 cm in depth. A globe issituated, when exists, at the point ofbending or turning of the shaft. The
transverse section of a shaft is usually
circular with a diameter of 2.0-2.5cm and:unusually of only 0.7 cm (Table 3). Even
one and a single shaft varies its diameterfrom part to part noticeably. A verticalshaft goes down from a globe by somedistance to the other globe. Further
downward extension of the shaft may bevertical or oblique and, finally, the lowest
part spreads horizontally by complicatedbranching. Horizontal tunnels are notalways sharp at the boundary between
sediment outside.
Globes and branching of shafts areobserved at irregular intervals. Branching of upturned Y -shape is common.
Boundary between mucus-coated wall ofburrows and the surrounding sediment is122Tsugio SHUTO and Shigeyoshi SHIRAISHI

Table 3. Size-frequency of shafts of Thalassinoides iwayaensis ichnosp. nov. in the v-bed.
Diameter of shaft

5-10

10-15

15-20

20-25

25-30

30-35

frequency

28

27

35

20

4

1

readily recognized on globes and connecting shafts, but is very obscure on the
branching part of shafts without globe.
Horizontally spread tunnels, which may
be feeding traces, are often deformed byload of sediments to show irregularly
oval shape in transverse section. In more
deformed cases, they do not reveal tubularfeature at all. Ornament is not observedon the wall-surface of any part of burrow.
Comparison: The type B consists of aburrow system of vertical shafts, horizontal tunnels and globes on its downward extension and is provided with asmooth walL Accordingly it is referredto Thalassinoides Ehrenberg, 1944 and isnamed T. iwayaensis.
The frequency of shafts and tunnels ofThalassinoides iwayaensis in an observed
quadrat shows a tendency similar to thatof Ophiomorpha ashiyaensis, but the tendency is much more exaggerated in T.
iwayaensis than in O. ashiyaensis. That
is to say, shafts are much denser thantunnels in the upper part of each bed andare scarcer in the lower part (shaft/tunnel
ratio in a vertical quadrat being 12: 1
and 2: 3 respectively in the upper andlower part) (Table 2).
The present ichnospecies is similar toThalassinoides callianassae EHRENBERG,
the type-species of the ichnogenus Thalassinoides, from the Burdigalian bank sandstone of Burgschleinitz, Austria, but theformer is distinguished from the latterin having much denser and more complicated network of tunnels.
GLAESSNER (1964) described a burrow
system of Callianassa major SAY from the

35-40

Eocene Pebble Point Beds, Victoria. On
that occasion he emphasized its characteristic features as follow; (1) generally
straight shaft with more or less angularchange in direction, (2) bifurcating but
not arborescent branching, (3) limited
size range, (4) smooth surface of wallwithout agglutination of pellets or sands,
and (5) occurrence of blind ends. Thisburrow system is evidently different from
Ophiomorpha major, which includes theburrow of living Callianassa major, inbeing devoid of pellet-coated wall of the
shaft and must be referred to Thalassinoides. T. iwayaensis is somewhat
similar to GLAESSNER'S specimen, but theformer is separated from the latter inbeing provided with complicated networkof tunnels.
Thalassinoides paradoxica (W OODW ARD)
from the Lower Chalk of southern England (KENNEDY, 1968) is similar to thepresent species in a general pattern ofthe burrow system, particularly in its
horizontal and branching network, but
the former penetrates to a shallower
depth and has larger shafts and tunnels
than the latter.
Thalassinoides iwayaensis shows someresemblance to T. ichnosp. [=Spongites
ichnosp.] from the Miocene Upper Marine
Molasse of Swiss (SEILACHER, 1955), but
the latter is much more regular in alternately branching system than the former.
OHSHIMA and NEMOTO (1968) reported
a feeding structure of Callianassa japonica
ORTMANN from the Eocene Wakkanabe
Formation, Hokkaido, Japan, which showsa circular transverse section with a diameter of 1.0-1.5 cm and has globes at theIchnofauna of the middle Ashiya Gro'ttp
points of bending and bifurcation. T.
iwayaensis is distinguished from the burrows described by OHSHIMA and NEMOTO
in much larger diameter and closer to
GLAESSNER'S specimen.
IMAIZUMI (1959) recorded "sand pipes"
associated with CaLLianassa bona IMAIZUMIin the Middle Miocene Hatatate Formation of the Natori Group, Miyagi Prefecture, Japan. Although he did not giveany descriptive feature of these sandpipes, his mention of the similarity of
his sandpipes to GLAESSNER'S CaLLianassa
burrow (GLAESSNER, 1964) suggests a
presumable similarity between T. iwayaensis and the Hatatate specimens.
ARAKI (1959) described the elbow-shaped
sandpipes from a siltstone of the Miocene
Kaisekizan Formation, Mie Prefecture,
Japan. He reported them in association
with the detached palms of CaLLianassa
dr. C. yagii IMAIZUMI, Panope, Dosinia,
CulteLLus, Chione and Glycymeris in one
and the same bed and he referred to theidentity of those trace structures to
CaLLianassa yagii. His specimens are
somewhat similar to T. iwayaensis in
shape and size, but sufficient comparison
can not be done because his specimen
represents only a small portion of a burrow system. NOMURA and HATAI (1936
and 1937) reported parts of large burrows
from the basal member of the Miocene
Suenomatsuyama Formation, Ninohe district, Aomori Prefecture and the Miocene
Yanagawa Formation, Fukushima Prefecture, North Japan, but a detailed comparison of those fossils with C. iwayaensis
is impossible by the same reason as forthe preceding example.
Thalassinoides iwayaensis resembles aburrow of Recent CaLLianassa japonica
ORTMAN, which, according to OHSHIMA(1967a and b), is characterized by a Yshaped pattern of the upper shaft above
the turnaround, a very narrow entrance123with a knobby wall, a pellet moundaround the opening and the irregularly
branching lower part. Any perfect burrow system of T. iwayaensis was notobserved. However, its average feature
is different from the burrow of Callianassa
japonica in lacking the extremely narrow
uppermost shaft with knobby wall andin having more complex tunnels.
Occurrence: Thalassinoides iwayaensis
occurs densely in muddy fine sandstonesof the tn U r and vrbeds. The t,-bed islithologically differentiated into a few
parts and T. iwayaensis extends downward beyond the lithological boundary,although the boundary is rather gradational. Namely, burrows penetrate throughthe upper Glycymeris layer into the underlying muddy sandstone. The densityof shafts is highest (2.3/100 cm 2, averaged
from the counts made in one quadrat) inthe upper part and decreases toward thelower part, which is featured by onion
structure. Sediment, filled in burrows, islaminated and coarser than the surrounding sediment. In the u,-bed, burrows are
distributed uniformly and extend downward from the upper boundary of thebed. Obvious globes are preserved. In
the v,-bed, burrows are distributed densely below the middle of the bed and associated with a Dosinia-Solen assemblage,
while their numbers gradually decrease
toward the fine sandstone in the upper
part, which contains a Venericardia-Acila
assemblage (Ioc. 1-14).
Thalassinoides iwayaensis is yielded in
the upper trbed together with apparently
autochthonous individuals of Solen connectens, which were found conjoined· andin life-position holding their long axes
vertically. T. iwayaensis rarely coexists
with Acila ashiyaenssis and Venericardia
subnipponica (Ioc. 1-14) and with Pitarashiyaensis and Euspira ashiyaensis (loc.
1-24). That is to say, the present ichno-

124

Tsugio SHUTO and Shigeyoshi SHIRAISHI

species is most typical of the lower tidal
and upper subtidal zones affected by thecoastal water, but shows a wide rangeof association with such molluscan species
indicative of environments ranging froma protected embayment to an offshore
environment.
Thalassinoides giganteus ichnosp. nov.
(Crustolithida, type C)
PI. 16, Figs. 1, 2, 5,7 and 8 and Text·fig. 5A

Holotype: GK-L 8735a and paratype
GK-L 8735b from the a 2 -bed.
Diagnosis: Large and com plicately
branched burrow system attaining about
100 cm deep and 300 cm wide and consisting of shafts, tunnels and globes. Tunnels forming polygonal network. Wallof shaft and tunnel smooth.
Morphology: The burrow system of
the type C consists of shafts with smooth wall and network of horizontal tunnels and is referred to Thalassinoides.
It is very large penetrating downward
to a depth of 100 cm and spreading horizontally in two to three meters. Shafts
and tunnels have a diameter of 4-5 cm.
A single burrow system has two or more
openings, immediately below which someshafts are remarkably narrowed to form
Shafts often converge,
nozzle-shape.
curve and ramify in their downward
course irregularly. Horizontal tunnels
form complicated, often polygonal, network and tend to be deformed by loadof sediment exhibiting a flattened profile.
They have usually blind ends. Globes
exist often at the points of branching
and chamber-like spaces are rarely seen
on some shafts. A mucus-coated wall isdiscernible on vertical shafts but is notobserved on horizontal tunnels. The wallis 3 mm thick and smooth both insideand outside. In-fillings of the burrow

are mixture of coarse sand and mud.
Comparison: Thalassinoides giganteus
is featured by its very large size, nozzlelike opening, smooth wall and polygonal
network of horizontal tunnels. It issimilar to T. saxonicus (GEINITZ), particularly those from the Lower Chalk ofsouthern England (KENNEDY, 1967), but
the former is distinguished from the latter in the surface texture of the shaft
and tunnel. While T. saxonicus has mammilated wall of shafts with elongatemamillae arranged their long axes parallelto the direction of the shaft, T. giganteus
has smooth wall of shafts.
Thalassinoides giganteus somewhat resembles the burrow of living Laomedia
astacina DE HAAN. According to OHSHIMA(1967a), L. astacina, a detritus feeding
sandy mud dweller, builds a moundaround the opening of the burrow. Itsburrow system consists of three parts;
the first cylindrical small shaft immediately below the pleural opening, succeeding looping second part and remarkably
larger and longer third part. T. giganteus
is obviously devoid of the looped part.
UTASHIRO et al. (1968) described the burrows of L. astacina in detail. On that occasion they referred to the complicately
branched lower part and very large pellets (20 mm X 16 mm X 16 mm) of rhomboid
or ellipsoid shape. The above featuresof L. astacina are clearly different fromT. giganteus.
Occurrence: Thalassinoides giganteus
occurs in poorly sorted sandy mudstones
with coarse sand patches in the top partof the a 2 -, aa- and a.-beds and blacksiltstones with wood-fragments in thebasal part of the same beds. These beds
probably represent a lagoonal facies. T.
giganteus in the upper sandy mudstone
never extends upward to the sorted
medium sandstone of the b-bed with
Ophiomorpha ashiyaensis and downward

Ichnofauna of the middle Ashiya Group125

mdy ssThalassinoides
iwayaensis

kochiensis

Fig. 6. Faunal and lithological association of the ichnospecies in the Jinnoharu Sand·stone Member of the middle Ashiya Group.
Areas encircled by solid lines respectively represent one lithological type. Ichnospecies
occurring together are connected by arrows.

to the calcareous muddy conglomerate
beyond the lithological boundary. In thebasal a-bed, they never cross the lower
lithological boundary too and are often
truncated at the upper portion (truncatedpre-erosion burrow).
In general, T.
giganteus does not associate with anyother ichno- and biospecies.
Ichnogenus Cylindrichnus HOWARD, 1966
type-species: Cylindrichnus concentricus
HOWARD, monotype
Cylindrichnus japonicus ichnosp. nov.
(Rectotubae, type D)
This ichnospecies includes distinct two
forms, concentric and eccentric forms.

Holotype: GK-L 8737 from the Prbed
representing the concentric form. Paratype: GK-L 8739 from the same bed representing the eccentric form.

C. japonicus, concentric form
PI. 18, Figs. 3, 5 and 6

Diagnosis: Concentrically multilayered,cylindrical, vertical and straight. Sizemoderate, 10-25 mm in diameter and 10
cm or less in depth.
Morphology: The burrow is a cylindrical tube consisting of many concentric
layers. It is circular in transverse section with an outer diameter of 10-25 mm(max. 30 mm), straight and vertical orslightly bent without ramification to at-

126

Tsugio SHUTO and Skigeyoski SHIRAISHI

tain about 10 cm long or less. It has
generally a small opening of about 5 mm
in diameter on an omission plane. The
opening is situated at the center of aburrow and almost constant in diameter
irrespective of the outer diameter of theburrow. That is to say, a larger burrow
has a thicker wall, which is whitish,
somewhat calcareous, thick and concentrically multilayered.
Comparison: Multilayered cylindricalburrows of the type D are referred to
Cylindrichnus HOWARD, 1966. Comparing
with slightly conical C. concentricus
How ARD, the type-species of the ichnogenus, the present ichnospecies is much
more cylindrical.
The burrow of this type reminds the
epi-siphonal mucus-coated structure ofdeeply burrowing bivalves (Exogenbedingte Mehrwandigkeit, REINECK, 1968).
According to his explanation of the origin, mucus-coated concentric layers become multiplied when the burrower
dwells for relatively long duration at one
and the same burrow under very slow or
non-depositional condition. It is not clear
whether or not the trace producer of theconcentric form of C. japonicus is bivalve,because no body fossil was found in theburrow in a life position. However, it
is very suggestive that the present form
is frequently associated with deep burrowing bivalves, Lucinoma nagaoi OYAMA
and MIZUNO or Angulus maxim us (NAGAO).
Burrows of Scopimera globosa DE HAAN
and Ilyoplax pusillus (de HAAN) describedby UTASHIRO and HORII (1965) havesomewhat similar configuration to thepresent ichnospecies, but the former two
are distinguished from the latter in being
devoid of multi-layered structure and indifference in size.
Occurrence: The concentric form of
C. japonicus occurs in muddy sandstoneof the uppermost part of the PI-bed inassociation with trace-fossils of Ophiomorpha ashiyaensis, eccentric form of
Cylindrichnus japonicus, Tosalorbis?
ichnosp. and Unarites ? ichnosp. and bodyfossils of Lucinoma nagaoi and Angulus
maximus. No other bivalve species isknown in association with the present
ichnospecies.
C. japonicus, eccentric form
(Rectotubae, type E)
PI. 18, Fig. 3

Diagnosis: Eccentrically multilayered,cylindrical and straight burrow. Sometimes curved in the lower part. Sizemoderate attaining about 10 mm in diameter and 15 cm in depth.
Morphology: Burrows of the type E
are multilayered, regularly cylindricaland vertical with length of about 15 cm.
Majority of them are straight, but someare slightly curved at the lower part
forming J-shape or hook-shape. Transverse section of the burrow is circularwith an outer diameter of about 10 mm.
Burrows open their entrance on an omission plane and stretch downward without
ramification. A small opening, about 5
mm in diameter, is not situated at thecenter of a burrow but is eccentricallylocated. An opening is rarely coveredby a white lid-like object. Burrows do
not show any sign of collapse by load.
The wall is whitish, 1-2 mm thick andconcentrically multilayered.
Comparison: The eccentric form of C.
japonicus closely resembles the above
described concentric one, but the typicaleccentric form is smaller in diameter andlonger in extension than the latter andits opening is not situated at the centerof a tube. Frequency-distribution ofmorphological characters of the two formssuggests that they are not necessarily

Ichnofauna of the middle Ashiya Group
continuous morphologically to each otherand that the two might have been madeby different organisms. However, thedata, particularly those of the concentric
form, are not satisfactorily plenty andsome specimens show intermediate features between the two. Hereby the twoforms are described as different forms
within a single ichnospecies.
Deeply burrowing bivalves which occur
together with this mucus-coated multilayered burrow are Angulus maximus andLucinoma nagaoi. However, the contributor of the eccentric form is not confirmed, because the association of theburrows and Angulus and Lucinoma is
exemplified only by a single case (loc. 128b, lower part of the b2-bed). And evenin this case, the body fossils do not lie
at the base of the ichnofossils, but are
separated from the latter at some shortdistance.
Occurrence: The eccentric form occurs
at several horizons and their density isvery high attaining 5 per 100cm2(averageof the counts in a quadrat of 40 cmx50
cm at the uppermost part of the b2-bed).
It coexists with Ophiomorpha ashiyaensis
without any exception, but does not occur
or occurs very rarely where O. ashiyaensis is extremely dense. This form isalso associated with O. ashiyaensis in the
muddy sandstone of the uppermost partof the A2-bed together with traces of thetype G. In the latter case, clusters of
the eccentric form and the type G areseparated from each other. This factmust suggest microhabitat-seggregationof the builders of two ichnospecies.
Ophiomorpha ashiyaensis, associatedwith the eccentric form of C. japonicus,
is devoid of a pellet mound in the A 2-,lower b2- and upper qrbeds and provided
with a mound in the An middle b2-,
upper b3 - and drbeds. This fact suggeststhat the above tracefossils were formed

127

in the tidal zone and in a quiet subtidal
zone.
Ichnogenus Tosalorbis KATTO, 1960
type-species: Tosalorbis hanzawai
KATTO,o.d.
Tosalorbis ? ichnosp.
(Rectotubae, type F)
PI. 18, Fig. 7

Representative specimen: GK-L 8740
from the Pl-bed.
Morphology: A horizontally or slightly
obliquely lying holostructure. About 1cm
wide and 10-20 cm long. The structure
shows various shapes ranging from simple
arc to sigmoid or V-shape and is circularin transverse section. One extremity ofa trace is round and somewhat larger
than the tapering opposite extremity.
The most conspicuous feature of thistrace fossil is a close-set septa-like structure which is obliquely orientated to thelongitudinal axis. The septa-like partseems materially similar to the mucuscemented outer wall and may represent
a spreite structure.
Comparison: The present trace-fossil
reminds the moving trace of heart urchin,but the mucus cemented structure of theformer is much smaller and more regularin shape than the latter.
It is also similar to Scalarituba WELLER,
1899, but is easily distinguished from thelatter by its three to four times larger
size and less conical septa-like structure.
KATTO (1960) described Tosalorbis hanzawai and T. peculiaris on the basis of
the material from the Paleogene of Shikoku, Japan. According to the original
author, Tosalorbis is a complete structure
characterized by its "serpentine-like feature" with "parallel rings". Therefore
the present trace-fossil from the Ashiya

128

Tsugio SHU TO and Shigeyoshi SHIRAISHIGroup basically resembles Tosalorbis. T.
hanzawai is represented by a fragmentof 55 mm long and has 18 septa per 10mm, while T. peculiaris is more than
20 cm long and has 10 septa per 10 cm.
The present ichnospecies is apparently
closer to T. peculiaris than to T. hanzawai in regard to the septal structure.
However, definite identification is suspended here because of insufficient material.
Occurrence: Tosalorbis ichnosp. occurs
in the uppermost part of the PI-bed
together with Ophiomorpha ashiyaensis,
Cylindrichnus japonicus, C. eccentricus
and the type H. T. ichnosp. forms clusters
in the middle part of the dl-bed. Although their position in the sediment isimmediately below a stratification plane,
they are not strictly horizontal, but may
be obliquely curved inward in some cases.
Ichnogenus Nankaites KATTO, 1964
type-species: Nankaites kochiensis
KATTO, o. d.
Nankaites kochiensis KATTO(Cryptoreptida, type G)

is quite identical to Nankaites kochiensis
KATTO from the Eocene Shimizu Formation of Tosashimizu. Shikoku, except fora slight difference that the former isless flat than the latter. The last mentioned feature, however, is not a diagnostic to the ichnospecies. but may be a
result of a influence of the post-depositional condition.
It is also similar to Torrowangea
WEBBY, 1970, but the former lacks thetransverse annulation. Nankaites koch iensis is similar to the trace made bysome Polychaeta, for example, the traceof Streblospio benedicti WEBSTER illustrated by FREY (1968). The latter is 2030 mm long, almost horizontally lying,nearly straight, weakly sigmoidal orslightly curved. Surface is simple andsmooth. However, concrete reference tothe identity of the builder can not begiven here, because the structure is too
simple and many organisms are expected
to build similar structure.
Occurrence: Nankaites kochiensis occurs in cluster near the upper boundaryof the muddy sandstone of the uppermost
part of the A 2 - and the As-bed in association with Ophiomorpha ashiyaensis andCy lindrichnus eccen tricus.

PI. 18, Fig. 4
1964, Nankaites kochiensis KATTO. Res. Rep.
Kochi Univ .• Vol. 13. Nat. Sci. J, No.
6. p. 55 (11), pI. 6, fs. 3 and 4.

Representative specimen: GK-L 8741
from the A3-bed.
Morphology: A small full structurewith width of 2 mm and length of about
30 mm. The shape of a cross-section isoval and wider than thick. Traces may
be straight, sinuous or irregularly curved
and very rarely ramified. The surface
of a trace is not very smooth and devoidof any ornament.
Comparison: The present ichnospecies

Ichnogenus Unarites MACSOTAY, 1967
type-species: Unarites sulekilVIAcsOT AY, monotype
Unarites ? ichnosp.
(Cryptoreptida. type H)
PI. 18, Figs. 8 and 9

Representative specimen: GK-L 8743
from the cz-bed.
Morphology: Horizontally orientatedsmall epirelief with length of about 10cm.
Diameter is variable even in a single
trace ranging from 2.5 to 5.0 mm (rarely

129

Ichnofauna of the middle Ashiya Group
10 mm). Majority of traces are straightened, slightly sinuous and not ramified,
but some have short thorn-like ramifications. Traces often cross over others
and have superficially an appearance oframification of T-shape, Y-shape or crossshape. Sometimes globe-like broad spaces
exist irregularly. The surface is somewhat uneven, but does not show any
definite or regular sculpture.
Comparison: The present ichnospecies
is similar to the preceding one, but theformer is readily distinguished from thelatter in larger and straight form withshort thorn-like ramification.
KSIAZKIEWICZ (1970) reported Unarites
submontana (AZPEITIA) as Palaeochorda
submontana from the Lower Eocene
Beloveza Beds of the Polish Carpathians.
The present ichnospecies closely resembles U. submontana in size, general shapeand particularly in ramification, but theformer is distinguished from the latterin straighter form. Concrete referenceof the present ichnospecies to Unarites
Macsotay, 1967, is suspended, because theformer is epichnial instead of hypichnial
nature of the latter.
Occurrence: The present ichnospecies
lies horizontally on the scoured plane at
the top of both the ba- and the Prbed
and on the lower omission plane within
the c2 -bed in association with Ophiomorpha ashiyaensis (b n Pr and c2 -bed),
Cylindrichnus eccentricus (do.) andTosalorbis ichnosp. (b s- and Prbed).

FS

OSS

v
U

5

r
q

0:::

P

UJ

CD

:2:
UJ

:2:
vi
vi
:::J
0:::

0

n
m
k

«

:c
0

z
z

-.

h

9
e
d

C(

c
b
a
A
B

C
0

IV. Bathymetric change throughthe middle Ashiya GroupSHUTO and SHIRAISHI (1971) discussed
on bathymetric and hydroenergetic conditions of the ecological environments
for the molluscan fossil communities of
the Iwaya district through a comparisonof the fossil and recent benthic molluscan

Fig. 7. Fractuation in the marine condition through the middle Ashiya Group.
L: lagoonal facies, FS: foreshore facies,
ass: offshore-bar facies, aSSL: offshore sublittoral, sl: sea-level at highand low tide. Lithology dr. Fig. 2.

130

Tsugio SHU TO and Shigeyoshi SHIRAISHI

communities and sedimentary indices of
their environmental factors. However,many of the strata remained unexplained,
because molluscan faunules are yieldedin the limited horizons. This time, environmental consideration is supplemented by the knowledge on the trace-fossils.
A shallowing sedimentary environmentis clearly indicated by a gradual changeof lithology from finely stratified mudstone with Palaeotaxodonta assemblagesof the main part of the Norimatsu member to medium sandstone with Ophiomorpha of the top of the member (Abed) through muddy sandstone and finesandstone. Bathymetric change from thelower sublittoral to the foreshore zone
may be presumable. The overlying muddy calcareous conglomerate accompanying carbonaceous siltstone layers both inits upper and lower parts (a-bed, basal
Jinnoharu Member) may represent a lagoonal facies. Then, the foreshore facies
was maintained until the deposition of
the e-bed with an ephemeral interuption
by sublittoral silty facies (a-bed). Afterthe deposition of the e-bed, offshore-bar
facies prevailed in the area (f- top-bed).
During the deposition of the q- to v-bed,
a quiet foreshore facies protected byoffshore bars prevailed with intercalationof offshore mound facies (r- and s-bed).
Thereafter the sedimentary environment

again became gradually deeper (Fig. 7)

Works Cited
ARAKI, Y. (1959): Sand· pipes from the Kai·
sekizan formation (Miocene) in the Northof Tsu City, Mie Prefecture, Japan. Bull.
Lib. Arts Dep., Mie Univ., no. 21, p. 93101 incl. 2 pis.
BROMLEY, R. G. and FREY, R. W. (1974): Re·
description of the trace fossil Cyrolithes
and taxonomic evaluation of Thalassinoides, Ophiomorpha and Spongeliomorpha.
Bull. Ceol. Soc. Denmark, vol. 23, p. 311335.
DEECKE, W. (1895): Eocane Kieselschwamme
als Diluvialgeschiebe in Vorpommern und
Naturwiss. Ver. Neu.
Mecklenburg.
Vorpommern u. RUgen, Mittil. Bd. 26(1894), S. 166-170, Taf. 1. (non vidi, in
HANTZSCHEL, 1975).
DIKE, E. F. (1972): Ophiomorpha nodosa
LUNDGREN: Environmental implicationsin the Lower Greensand of the Isle ofWight. Proc. Ceol. Assoc., vol. 83, p.
165-177, pis. 13-14.
DUDICH, E. (1962): Ein neues AnnelidenWohnrohr aus dem helvetischen Schotterkomplex in der Nahe von Bhdapest.
Foldtani Kozlony, vol. 92, p. 107-109.
EHRENBERG, K. (1938): Bauten von Decapoden(Callianassa sp.) aus dem Miozan (Burdigal) von Burgschleinitz bei Eggenburg
in Gau Nieder-Donau (Nieder Osterreich).
PalCiont. Zeitschr. Bd. 20, S. 363-384, Taf.
27-29.

Explanation of Plate 16
Figs. 1, 2, 5, 7 and 8. Thalassinoides giganteus ichnosp. nov.
1 and 2: tunnels and parts of shafts in the as-bed.
5 and 7: polygons of tunnels in the a2·bed. Holotype specimen GK-L 8735a is a part of thepolygons in Fig. 5.
8: nozzle-like uppermost part of a shaft. Paratype GK-L 8735b.
Figs. 3 and 4. Ophiomorpha ashiyaensis ichnosp. nov.
3: pellet-coated tunnel. Holotype specimen GK-L 8725a was obtained from the ngured
tunnel.
4: pellet-coated shaft. Para type specimen GK-L 8725c was obtained from the figured shaft.
Fig. 6. Distribution of shafts of Thalassinoides iwayaensis ichnosp. nov. in the v I-bed on awave-cut bench.

SHUTO and SHIRAISHI:

Ichnofauna of the rniddle Ashiya g1' OUP

Plate 16

Ichnofauna of the middle Ashiya Group
FI~EY,

R. W. (1968): The Lebensspuren ofsome common marine invertebrates near
Beaufort, North Carolina. I. Pelecypod
burrows. Jour. Paleont., vol. 42, p. 570574.
- - , HOWARD, J. D. and PRYOR, W. A. (1978) :Ophiomorpha: its morphologic, taxonomic,
and environmental significance. Palceogeogr., Pclaeoclim., Palaeoecol., vol. 23,
p. 199-229.
FURSICH, F. T. (1973): Thalassinoides andthe origin of nodular limestone in the
Corallian Beds (Upper Jurassic) of southern
England. N. Jb. Geol. Palciont., Mh.
(1973), S. 136-156.
GEI1'ITZ, H. B. (1839-1842) : Charakteristik der
Schichten und Petrefacten des siichsischbohmischen Kreidegebirges. S. 1-116, Tat.
1-24. Arnold, Dresden & Leiptig. (nonvidi, in HXNTZSCHEL, 1975).
GLAESSNER, M. F. (1946): Decapod crustacea(Callianassidae) from the Eocene ofVictoria. Pr"c. Roy. Soc. Victoria, vol.
59, p. 1-7, pIs. 1-2.
GOPPERT, H. R. (1842): Ueber die fossile
Flora der Quadersandstein-formation in
Schlesien, als erster Beitrag zur Flora der
Tertia.rgebilde. Nove. Acta Cees. Leop.Carol. German. Nc.tur. Curios Bd. 19,
Lief. 2, S. 97-134, Taf. 46-53. (non vidi.
in HXNTZSCHEL, 1975).
HANTZSCHEL, W. (1952):
Die Lebensspur
Ophiomorpha LUNDGREN in Miozan bei
Hamburg, ihre weltweite Verbreitung und
Synonymie.
Mitteil. Geol. Staatsinst.
Hamburg, Heft. 21, S. 142-153, 2 Taf.
- - (1975): Trace fossils and problematica(2nd ed.) in R. C. MOORE (ed.) Treatiseon Invertebrate Paleontology, pt. W,
Miscellanea, Supplement 1, p. 1-269.
- - and KRAUS, O. (1972): Names based on
trace fossils (ichnotaxa): request for a
recommendation. Z. N. (S.) 1973. Bull.
Zool. Nomenclature, vol. 29, p. 137-141.
HATAI, K. (1938): On some species of fossil
Dosinia from Japan. Japan. Jour. Geol.
Geogr., vol. 15, nos. 1-2, p. 47-66.
- - and KOTAKA, T. (1968): Faecal pellets
from the Kogota formation (Early Miyagian) of Kogota-machi, Miyagi Prefecture.

131

Saito Ho-on Kai Mus. Res. Bull., no. 37,
p. 43-47.
- - , - - and NODA,H. (1970): Supplementary
note on the faecal pellets from the early
Miyagian Kogota formation, Kogota-machi, Miyagi Prefecture, Northeast Honshu,
Japan. ibid. no. 39, p. 7-11.
HILLMER, G. (1963): Zur Okologie von Ophiomorpha LUNDGREN. N. Jb. Geol. Paliiont.
Mh. (1963), S. 137-141.
HIRA YAMA, K. (1956):
Tertiary Mollusca
from Hikoshima, Yamaguchi Prefecture,
Japan, with remarks on the geological ageof the "Ashiya fauna". Sci. Rep. Tokyo
Kyoiku Daigaku, Sec. C, no. 45, p. 81-127,
pis. 6-8.
HOWARD, J. D. (1966): Characteristic trace
fossils in Upper Cretaceous sandstones of
the Book Cliffs and Wasatch Plateau.

Utah Geol. Mineral. Survey, Centml Utah,
Coal Bull., vol. 80, p. 35-53.
HOYT, J. H. and WEIMER, R. J. (1963): Comparison of modern and ancient beaches,
central Georgia coast. Bull. Amer. Assoc.
Petrol. Geologists, vol. 47, p. 529-531.
IMAIZUMI, R. (1959): Callia.nassa bona n. sp.
from near Sendai, Miyagi Prefecture.
Japa.n. Jour. Geol. Geogr., vol. 30, p. 3137, pI. 4.
KAMADA, Y. (1967): Vicarya from the Ashiya
group in Shimonoseki, Southwest Japan.

Commemorate Volume Prof. Hcyasaka's
77th Birthday, p. 175-179, 1 pI.
- - (1969): Existence of the Oligocene molluscan fauna in Japan. Fossil, no. 18, p.
41-47. (in Japanese).
KATTO, J. (1960): Some problematica fromthe so-called unknown Mesozoic strata ofsouthern part of Shikoku, Japan. Sci.
Rep. Tohoku Univ. 2nd Ser. (Geol.), Spec.
Vol., no. 4, p. 323-334, pIs. 34-35.
- - (1964): Some sedimentary structures
and Problematica from the Shimanto terrain of Kochi Prefecture, Japan. Res.
Rep. Kochi Univ., vol. 13, Nat. Sci. I, no.
6, p. 1-14, pis. 1-7.
KEIJ, A. J. (1965): Miocene trace-fossils from
Borneo. Paliiont. Zeitschr., Bd. 39, S. 220228, Tat. 28-29.
KENNEDY, W. J. (1967): Burrows and surface

132

Tsugio SHUTO and Shigeyoshi SHIRAISHI

traces from the Lower Chalk of southern
England. Brit. Mus. Nat. Hist. (Geol.)
Bull., vol. 15, p. 125-167.
- - and MACDoUGALL, J. D. S. (1969): Crustacean burrow in the Weald Clay (Lower
Cretaceous) of south-eastern England andtheir environmental significance. Palaeontology, vol. 12, p. 459-472.
KILPPER, K. (1962): Xenohelix MANSFIELD
1927 aus der Miozanen niederrheinischen
Braunkohlenformation. Paliiont. Zeitschr.
Bd. 36, S. 55-58, Taf. 7.
KSIAZKIEWICZ, M. (1970): Observations on
the ichnofauna of the Polish Carpathians.
in CRIMES, T. P. and HARPER, J. C. (eds.)
Trace Fossils. Geol. Jour. SPec. Issue, no.
3, p. 283-322. Seel House Press, Liverpool.
LESQUEREUX, L. (1873): Lignitic formationand fossil flora. U. S. Geol. Surv. Territories, Ann. Rep., vol. 6, p; 317-427.
LUNDGREN, S. A; B. (1891): Studier ofver
fossilforande losa block. Geol. Foren.
Stockholm, Forhandl., vol. 13, p. 111-121.
LUTZE, j. (1938): Ueber Systematik, Entwicklung und Oekologie von Callianassa.
Heligoland Wissensch. Meeresuntersuch.,
Bd. 1, S. 161-199.
MAXSOTAY, O. (1967): Huellas problematicas
y su valor paleoecologico en Venezuela.
Universidad Central de Venezuela, cuelade Geologia, Minas y Metalurgia (Venezuela),vol. 16, p. 7-79, pis. 1-18, 1 map.
MERTI:--:, H. (1941): Decapode Krebse aus
dem Subhercynen und Braunschweiger
Emscher und Untersenon sowie Bemerkungen tiber einige verwandte Formen in
der Oberkreide.· Nova Acta Leop.-Carol.
Haile, Bd. 10, Lief. 68, S. 149-262, Taf.

1-8.
MIZUNO, A. (1962-1963) : Paleogene and Lower
Neogene biochronology of West japan, 1III. Jour. Geol. Soc. Japan, vol. 68, no.
806, p. 640-648; no. 807, p. 687-693 and vol.
69, no. 808, p. 38-50 (in japanese).
NAGAO, T. (1928): Stratigraphy of the
Paleogene formations in Kyushu. XXI and
XXII. Jour. Geogr. vol. 40, no. 470, p. 193215 and no. 471, p. 278-288 (in japanese).
NOMURA, S. and HATAI, K. (1936): On theoccurrence of peculiar shaped concretions
probably due to certain decapod crustaceans. Japan. Jour. Geol. Geogr., vol. 13,
nos. 1-2, p. 57-61, pI. 11.
- - and - - (1937): Preliminary notes onsome sand pipes. Saito Ho-on Kai Mus.
Res. Bull.,no. 13, p. 147-153.
OSGOOD, R. G. (1970): Trace fossils of theCincinati Arc. Palaeontogr. Americana,vol. 6, no. 41, p. 281-409, pis. 57-83.
OSHIMA, K. (1967a): Burrows of japaneseThalassinidae. Earth Sci., vol. 21, no. 1,
p. 11-18. (in japanese).
- - (1967b): Some burrowing crustaceans
and shape of their burrows from the Usu
Bay, Hokkaido. Jubilee Pub I. Commen.
Prof. SA SA 60th Birthday, p. 241-257.
- - and NEMOTO, T. (1968): Some burrows
from Wakkanabe Formation. Geol. Surv.
Japan Abstr. Lecture, no. 19, p. 1-6. (injapanese) .
PATTERSON, j. M. (1942): Hal),menites, amarine sandstone indicator. Jour. Paleont.,
vol. 42, p. 271-273.
PmIL, M. E. (1946): Ecological observation
on Cailianassa major SAY at Beaufort,
North Carolina. Ecol., vol. 27, p. 71-80.

Explanation of Plate 17
Figs. 1, 2 and 8. Ophiomorpha ashiyaensis ichnosp. nov.
1: infillings of a branched tunnel in the eI-bed.
2: ditto, in the oI-bed.
8: shafts and tunnels in the oI-bed on a wave-cut bench.
Figs. 3-7 and 9. Thalassinoides iwayaensis ichnosp. nov.
3, 5, 7 and 9: shafts and tu'nnels in the VI-bed on a steep cliff.
4: branching part of a tunnel (Holotype GK-L 8731a) obtained from the tI-bed.
9: oblique shafts in the PI-bed with association of Solen connectens NAGAO. PaJ atype CK-L
8731b being the lirger shaft.

SHUTO and S HIRAISHI :Ichnofa~ma of the middle Ashiya group

Plate 17

Ichnofauna of the middle Ashiya Group
REINECK, H. E. (1968): Lebensspuren vonHerzigeln. Senckenbergiana Lethaea, Bd.
49, S. 311-319, 3 Taf.
SAPORTA, G. de (1887): Nouveaux documents
relatifs aux organismes problematiquesdes anciennes mers. Bull. Soc. Ceol.
France, Ser. 3, tom. 15, p. 286-302, pis.
3-7.
SARJEANT, W. A. S. and KENNEDY, W. J.
(1973): Proposal of a code for the nomenclature of trace-fossils. Can ad. Jour.
Earth. Sci., vol. 10, p. 460-475.
SAY, T. (1918): An account of the Crustaceaof the United States. Jour. Acad. Nat.
Sci. Phi/ad., vol. 1, p. 235-253.
SCHXFER, W. (1962): Actuo-Paliiontologie
nach Studien an der Nordsee. 666 pp., 36
pis. Waldemar Kramer (Frankfurt).
SEILACHER, A. (1955) : Die geologische Bedeutung fossiler Lebensspuren. Zeitschr.
Deutsch. Ceol. Cesel. Bd. 105 (Jahrg. 1953),
S. 214-227, Taf. 7-8.
SELLWOOD, B. W. (1971): A Thalassinoides
burrow containing the crustacean Clyphaea
udressieri (MEYER) from the Bathonianof Oxfordshire. Palaeontology, vol. 14, no.
4, p. 589-591, pI. 108.
SHIN, E. A. (1968): Burrowing in recent lime
sediments of Florida and the Bahamas.
Jour. Paleont., vol. 42, no. 4, p. 879-894.
SHUTO, T. (1978): Paleogene/Neogene boundary in Southwest Japan: A molluscan
biostratigrapher's view. Prof. N. I kebe
Memorial Volume, p. 61-72. (in Japanesewith English abstract).
- - and SHIRAISHI, S. (1971): The fossil
communities of the Ashiya group from the
Iwaya district. Sci. Rep. Kyushu Univ.,
vol. 10, no. 3, p. 253-270. (in Japanesewith English abstract).
STERNBERG, K. M. Graf von (1920-1938):
Versuch einer geognostisch-botanischen
Darstellung der Flora der Vorwelt. Bd.

1-8, S. 1-364, Taf. 1-136. F. Fleischer,
Leipzig u. Prague. (non vidi, in HXNT;7.SCHEL, 1975).
STOLL, N. P. et al. (1964): International Codeof Zoological Nomenclature, adopted by
the XV International Congress of Zoology,
London. International Trust for Zoological
Nomenclature, p. 1-176.
UTASHIRO, T. and HORII, Y. (1965): Ecology
and burrows of Scopimera globosa andIlyoplax pusillus. Res. Rep. Takada College, Fac. Educ. Niigata Univ. no. 10, p.
110-143, pis. 1-7. (in Japanese with English
abstract) .
- - et al. (1968): Ecology and burrows of
Laomedia astacina DE HAAN: Biologicalstudies in "Lebensspuren", Pt. X. Mem.
Takada Branch, Fac. Educ., Univ. Niigata,no. 13, p. 43-173 incl. 4 pis.
VIALOV, O. S. (1972): The classification of
the fossil traces of life. 24th Intern.
Ceol. Congr. Montreal, 1972, Proc. Ser.
7 (Paleont.), p. 639-644.
WAAGE, K. M. (1968): The type Fox Hills
formation, Cretaceous (Maestrichtian),South Dakota. I. The stratigraphy andpaleoenvironments. Bull. Peabody Mus.
Nat. Hist., vol. 27, p. 1-175.
WEIMER, R. T. and HOYT, J. H. (1964): Burrows of Callianassa major SAY, geologic
indicators of littoral and shallow neritic
environments. Jour. Paleont., vol. 38, no.
4, p. 761-767, pis. 123-124.
WELLER, S. (1899) : Kinderhook faunal studies.
I. The fauna of the vermicular sandstone
at Northview, Webster County, Missori.
Acad. Sci. St. Louis, Trans., vol. 9, p. 951, pis. 2-6.
WOODWARD, S. (1830): A synoptic table 0/
British organic remains. xiii+50pp., 1 pI.
London and Norwich. (non vidi, in KE:-':NEDY, 1967).

~tfLflim*~IK-!EiM:it!!lKt.::. 7Hfli" 7.:> f!iM~~!if[7J\.JIilI\ll!(7) mf. f&-!Ei$J[i (7) j::!]l;$I¥Jli1f~~ IT...,j::!]l;ft::5"(7)~~· 7NJit.::.m! 1....-C it..: ~*L.t.::1J~7'J'tJ:~,(7)-e, ':'(7)1iJf~-et*ffl 1....t.:~*t.:>(7)~:k...:1J C =.f~~ i f IJJl t.:>7'J,t.::. L.t':o lXt.::.M1mt.::. £vj~'-C i'iJ1tP-!Ei$~.i£:(7)j::!]l;ft::5"~lla~
1...., ~1mEt~tJ: ~~~ Uu:k... t.:o :/!l!:f~t'::'i'iJli'Y:E$~:llUJ!~(7) 7J\.1* • :it!!M~t'::'7'J'7'J'b7.:>~!ft~iY£t.:ot.::.~"& L.t':o

.

133

.

§~lX!!13 • B:Pfflt~

134

Tsugio SHUTO and Shigeyoshi SHIRAISHI

Explanation of Plate 18
Fig. 1. Pellet·mound of Ophiomorpha ashiyaensis ichnosp. nov. in the kl"bed.
Fig. 2. Bioturbation by Ophiomorpha in the ol·bed.
Fig. 3. Cylindrichnus japonicus ichnosp. nov., concentric form and eccentric form (with arrowmark) in the PI·bed.
Fig. 4. Nankaites kochiensis KATTO in the A2·bed. GK·L 8741.
Fig. 5 and 6. Cylindrichnus japonicus ichnosp. nov., concentric form on a vertical fracture wall.
Fig. 7. Tosalorbis? ichnosp. from the PI·bed. GK·L 8740.
Fig. 8 and 9. Unarites? ichnosp. from the c2·bed. GK·L 8743 being obtained from the cluster
in Fig. 8.

SHU TOand SHIRAISHI.'

Ichnofauna of the middle Ashiya g1"OU]J

Plate 18

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 115, pp. 135-142, pIs. 19, 20, Sept. 30, 1979

706. SOME INTERESTING FOSSILS FROM THE UPPER PALEOZOICIN CHAP ARRA AREA, SOUTHWEST PER U*NOBUO YAMAGIW A
Department of Earth Science, Osaka Kyoiku University, Osaka 543

and
CESAR RANGEL Z.
Instituto de Geologia y Mineria, Jesus Maria, Lima, Peru

Abstract. Four fusulinid species and one new coral species described in thisarticle were found from the Upper Paleozoic at the south of Pampa Lobos, Chaparraarea, Southwest Peru. Judging from the paleontological data, the present fossil
assemblage indicates an early Wolfcampian age.

SON, 1954) ; it is associated with Schubertella kingi, Pseudofusulinella utahensis,
Dunbarinella hughsensis and Schwagerina? sp. Some specimens referred to it witha query were found in the Lower Wolfcampian Bursum Formation of Hueco
mountains, Texas (THOMPSON and BISSELL in THOMPSON, 1954); they are associated with Schwagerina sp. Later
Triticites cellamagnus was found fromthe Lower Wolfcampian part of the
Earp Formation in Southeast Arizona(SABINS and Ross, 1963) together with T.
meeki and Schwagerina compacta. THOMPSON, DODGE and YOUNGQUIST (1958) and
SLADE (1961) also reported it from theLower Wolfcampian of Idaho and Nevada.
According to THOMPSON (1954) and
SLADE (1961), Triticites meeki occurs in
the Lower Wolfcampian of Kansas, Nebraska, Oklahoma, Texas, Arizona,Nevada
and Wyoming. It was also found fromthe Lower Wolfcampian part of the Earp
Formation, Southeast Arizona (SABINSIntroduction
Some fusulinid and coral specimens
were found in a rock fragment collectedby Eng. ORCHAUSKI from the Upper Paleozoic limestone exposed at the south ofPampa Lobos, Chaparra area, Southwest
Peru (15°58' S. Lat., 73°50' W. Long.).
In this article, the following four fusulinids and one new coral are described,
and their age is discussed.
Fusulinids: Triticites cellamagnus THOMPSON& BISSELL

Coral:

T. meeki (MOLLER)
T. sp. A
T. sp. B
Durhamina? andensis n. sp.

Triticites cellamagnus was originallydescribed from the Lower Wolfcampian
part of the Oquirrh Formation, Central
Utah (THOMPSON and BISSELL in THOMP-* Received Dec. 12, 1978; read June 3, 1978
at Tsukuba University.

135

136

Nobuo YAM AGIW A and Cesar RANGEL Z.

and Ross, 1963) together with Schubert ellakingi, Triticites creekensis, T. cellamagnus
and Schwagerina grandensis. It closely
resembles Triticites pajerensis and T. cf.
victoriensis described by ROBERTS in
NEWELL, CHRONIC and ROBERTS (1953)
from the Silvaseptopora zone of the Lower
Wolfcampian part of the CopacabanaGroup in Peru.
Triticites sp. A resembles T. cali/omicus
and T. pinguis. Triticites cali/ornicus has
been found from the Wolfcampian partof the Bird Spring Formation, California(THOMPSON and HAZZARD in THOMPSON,WHEELER and HAZZARD, 1946), where it
occurs in association with Schwagerina
proutdens, Dunbarinella concisa, Pseudoschwagerina voeseleri, Schubertella kingiand S. masoni. It also occurs in theLower Wolfcampian of the Great Basinregion, North America, according to BRILL(1963). Triticites pinguis was originallydescribed from the Lower Wolfcampian
in Texas (DUNBAR and SKINNER, 1937).
Later it was discovered from the Lower
Wolfcampian Neal Ranch Formation,
Texas (Ross, 1963) and from the Lower
Wolfcampian part of the Earp Formation,
Southeast Arizona (SABINS and Ross,
1963).
Triticites sp. B somewhat resembles
such specimens as T. titicacaensis and T.
aff. titicacaensis described from the Wolfcampian part of the Copacabana Groupin Peru (ROBERTS in NEWELL, CHRONIC
and ROBERTS, 1953; MAEDA, YAMAGIWA,
BELLIDO and RANGEL, 1974). However,the former is distinct from the latter
two in some important characters (seedescription).
On the other hand, one new coral
species, Durhamina? andensis n. sp. resembles D. ? uddeni (Ross and Ross, 1963 ;MINATO and KATO, 1965) from the Virgilian Gaptunk Formation of Texas andD. hessensis (Ross and Ross, 1962; MINATO

and KATO, 1965) from the Upper Wolfcampian Lenox Hills Formation, Texas.
Judging from these fossils the present
assemblage shows an affinity with thosefrom the Lower Wolfcampian in North
America and Peru. The writers consider
that the present fossils also indicate an
early Wolfcampian age.
Triticites sp. A, T. sp. Band T. sp. C
were formerly discovered and illustratedby BELLIDO and NARVAEZ (1960) fromthe Upper Paleozoic in Atico area, Southwest Peru. According to them, thefusulinids indicate a Pennsylvanian age.
However, the writers consider that thefusulinids may be related to the present
fauna in specific assemblage and may
indicate an early Wolfcampian age.
Acknowledgements
The wri ters wish to express theirhearty thanks to Eng. E. ORCHAUSI (Instituto de Geologia y Mineria, Lima) who
perimitted them to study the present interesting materials, to Prof. Emeritus H.
FUJIMOTO (Tokyo University of Education), Prof. S. MAEDA (Chiba University)and ex-director E. BELLIDO (Instituto deGeologia y Mineria, Lima) for their kindsuggestions and to Dr. Y. T AKEI (Geological Survey of Japan) for his assistancein consulting many needful references.
Photographic work was done by Mr. K.
NARUHASHI (Osaka Kyoiku University) towhom the writers extend their thanks.
Description of Species
Superfamily Fusulinacea
von MOLLER, 1878
Family Fusulinidae von MOLLER, 1878
Subfamily Schwagerininae DUNBAR
and HEN BEST, 1930
Genus Triticites GIRTY, 1904

706. Late Paleozoic fossils in Peru
Triticites cellamagnus THOMPSON
and BISSELL
Plate 19, fig. 1

1954. Triticites cellamagnus THOMPSON and
BISSELL in THOMPSON, p. 43, pI. 11,
figs. 1-12.
1954. Triticites cellamagnus (?), THOMPSON
and BISSELL in THOMPSON, p. 43, pI. 10,
figs. 14-17.
1958. Triticites cellamagnus:
THOMPSON,DODGE and YOUNGQUIST, p. 121, pI. 19,
figs. 13-15.
1961. Triticites cellamagnus: SLADE, p. 72,
pI. 10, fig. 2.
1963. Triticites cellamagnus: SABINS and
Ross, p. 345, pI. 36, figs. 13-15.

Shell is medium in size, fusiform, withstraight axis of coiling and bluntly
pointed poles. Lateral slopes of matureshell are slightly convex and nearlystraight. The first volution is subsphericalin shape; beyond the first volution, theshapes gradually become elongate. A
specimen having five volutions (pI. 19,
fig. 1) is 6.0 mm in length and 2.8 mm inwidth, giving a form ratio of about 2.l.
Proloculus is large in size, spherical inshape. Its outside diameter is 0.42 mm.
Height of chambers in the first to thefifth volution of the above mentioned
specimen is 0.09, 0.14, 0.16, 0.22 and 0.25mm, respectively. Spirotheca is thick,composed of a tectum and coarse alveolar
keriotheca. Its thickness in the first to
the fifth volution of the above mentioned
one is 0.04, 0.06, 0.Q7, 0.10 and 0.11 mm,
respectively. Septa are strongly fluted
in extreme polar regions, but gradually
decreasing in fluting towards the centerof shell, and almost unfluted above tunnel.
Chomata are distinct and massive throughout the shell except the last volution.
Tunnel angles in the first to the fourth
volution of the above mentioned one are25, 28, 30 and 35 degrees, respectively.

137

Remarks: The distinct characters of
the present form are its large proloculus,
fusiform shell of medium size, thickspirotheca and loosely coiled shell. The
features mentioned above practicallyagree with those of the original specimens of Triticites cellamagnus and T.
cellamagnus (?) described by THOMPSON
and BISSELL in THOMPSON (1954). The
present form resembles Triticites sp. A
in this article in many respects, but theformer differs from the latter in having
larger pro loculus. It is also similar to
Triticites meeki (MOLLER). However, theformer has larger proloculus and shorter
shell. It is distinguishable from Triticites
creekensis THOMPSON (1954, p. 42, pI. 9,
figs. 21-26, pI. 10, figs. 1-13; SLADE,
1961, p. 73, pI. 10, fig. 4; CASSITY and
LANGENHEIM, 1966, p. 951, pI. 113, figs.
19-22; STEINER and WILLIAMS, 1968, p.
56, pI. 11, figs. 1-5) in having larger
proloculus and convex or straight lateralslopes.
Occurrence: Limestone at the south ofPampa Lobos, Chaparra area, Southwest
Peru. The present form is associatedwith Triticites meeki, T. sp. A, T. sp. B
and Durhamina? andensis n. sp.
Repository: Reg. no. NSM-MPC 1844
(National Science Museum).
Triticites meeki (MOLLER)
Plate 19, figs. 5-7

1858. Fusulina cylindrica var. ventricosa:
MEEK and HAYDEN (part), p. 261.
1865. Fusulina cylindrica: MEEK and HAYDEN(part), p. 14, pI. 1, fig. 6a.
1879. Fusulina ventricosa var. meeki: MOLLER(part), p. 4.
1928. Triticites ventricosus: DUNBAR and
CONDRA (part), p. 84, pI. 1, fig. 2, pI. 3,
fig. 1, pI. 4, fig. 4.
1954. Triticites meeki: THOMPSON (part), p.
39, pI. 12, figs. 1-11, pI. 13, figs. 1-12.

138

Nobuo YAM AGIW A and Cesar RANGEL Z.

1961. Triticites meeki: SLADE, p. 72, pI. 10,
fig. 3.
1963. Triticites meeki: SABINS and Ross, p.
339, pI. 36, figs. 4-5.

Shell is elongate fusiform in shape,with bluntly pointed poles. Axis of coiling is almost straight. Lateral slopes
are convex to slightly concave. A mature
specimen having seven volutions (pI. 19,
fig. 6) is 4.3 mm in half length and 1.4 mm
in half width, giving a form ratio of
about 3.1. Pro loculus is medium in size,
spherical in shape, having outside diameter of 0.22 to 0.24mm. Average heightof chambers in the third to the seventh
volution is 0.10, 0.14, 0.19, 0.24 and 0.27mm, respectively. Spirotheca is relatively
thick, composed of a tectum and coarse
alveolar keriotheca. Its average thickness
is 0.02, 0.04, 0.05, 0.06, 0.08, 0.11 and 0.09
mm in the first to the seventh volution,
respectively. Septa are strongly fluted
in polar regions and weakly fluted incentral part. Chomata are distinct andasymmetrical in shape. A verage tunnel
angles in the second to the sixth volution
are 18, 20, 29, 38 and 36 degrees, respectively. Septal counts in the second to
the sixth volution of a specimen illustrated as fig. 7 on plate 19 are 16, 18, 20,
21 and 23, respectively.
Remarks: The present specimens arecharacterized by their elongate fusiform
outline, less inflated central area, medium
size of pro loculus and mode of septal
fluting. These features practically agreewith those of Triticites nzeeki (MOLLER).
Triticites meelli is very similar to T.
pajerensis ROBERTS in NEWELL, CHRONIC
and ROBERTS (1953, p. 186, pI. 37, figs. 35) and T. d. victoriensis DUNBAR and
SKINNER by ROBERTS in NEWELL, CHRONIC
and ROBERTS (1953, p. 191, pI. 37, fig. 8).
However, it seems to have more weakly
fluted septa than the two species. They
may belong to Triticites meeki.

Occurrence: Limestone at the south ofPampa Lobos, Chaparra area, Southwest
Peru. The associated fossils are Triticites
cellamagnus, T. sp. A, T. sp. Band
Durhamina? andensis n. sp.
Repository: Reg. nos. NSM-MPC 18481850 (National Science Museum).
Triticites sp. A
Plate 19, figs. 2-4

Shell is medium in size, inflated fusiform
in shape, with bluntly pointed poles,
straight axis of coiling and convex lateralslopes. A specimen illustrated as fig. 2
on plate 19 having five and a half volutions is 5.7 mm in length and 3.3 mm inwidth, with a form ratio of about 1.7.
Proloculus is medium in size, subsphericalin shape, with outside diameter of 0.24
to 0.26 mm. Average height of chambersin the first to the seventh volution is0.07, 0.09, 0.13, 0.18, 0.26, 0.28 and 0.29 mm.
respectively. Spirotheca consists of atectum and keriotheca with coarse alveoli.
Average thickness of the spirotheca in
the first to the sixth volution is 0.03, 0.05,
0.08, 0.09, 0.10 and 0.11 mm, respectively.
Septa are strongly fluted in polar regions,but weakly fluted in central portion.
Septal counts in the second to the sixth
volution for one specimen (pI. 19, fig. 4)
are 20, 21, 22, 21 and 23, respectively.
Average tunnel angles in the second to
the fifth volution are 23, 22, 27 and 30
degrees, respectively. Chomata are generally asymmetrical in shape, but indistinct in outer volutions.
Remarks: The present species resembles Triticites cali/ornicus THOMPON and
HAZZARD in THOMPSON, WHEELER and
HAZZARD (1946, p. 42, pI. 10, figs. 10-14)
in inflated fusiform shape, medium sizeof proloculus, mode of septal fluting,narrow tunnel angles and asymmetricalchomata. However, the former differs

706. Late Paleozoic fossils in Peru
from the latter as follows. (1) The
septal counts of the former are lessnumerous than the latter. (2) The former
shows smaller form ratio than the latter.
(3) The chomata of the former in outer
volutions are indistinct. The present
specimens are also similar to the original
specimens of Triticites pinguis DUNBAR
and CONDRA (1937, p. 620, pi. 47, figs. 1219), but differs from them in having lessnumerous septal counts, indistinct chomata in outer volutions, larger form ratio
and smaller pro loculus. They are somewhat related to Triticites pinguis by
SABINS and Ross (1963, p. 343, pI. 36,
figs. 6-12) and Ross (1963, p. 109, pI. 6,
figs. 1, 3-4). However, they have moreloosely coiled shell and indistinct chomata
in outer volutions. They are distinguished from Triticites d. plummeri DUNBAR
and CONDRA (SABINS and Ross, 1963, p.
347, pI. 36, fig. 7) in having more loosely
coiled shell and broader tunnel angles.
Occurrence: Limestone at the south ofPampa Lobos, Chaparra area, Southwest
Peru. The present specimens are associated with Triticites cellamagnus, T.
meeki, T. sp. Band Durhamina? andensis
n. sp.
Repository: Reg. nos. NSM-MPC 1845,
1846, 1847 (National Science Museum).

Triticites sp. B
Plate 19, fig. 8

Shell is small in size, inflated fusiform
in shape, with straight axis of coilingand bluntly pointed poles. Lateral slopesof mature shell slightly convex. A
specimen (pI. 19, fig. 8) of five and a half
volutions is 2.9 mm in length and 1.7 mm
in width, giving a form ratio of about
1.7. Proloculus is spherical in shape, withoutside diameter of 0.18 mm. Height ofchambers in the second to fifth volution

139

is 0.Q7, 0.08, 0.12 and 0.12mm, respectively.
Spirotheca consists of a tectum andkeriotheca. Its thickness in the third to
fifth volution is 0.03, 0.04 and 0.06 mm,
respectively. Septa are highly fluted inpolar regions, but they become weakly
fluted towards the middle portion. Chomata asymmetrical in shape, but indistinct in outer volutions. Tunnel angles
in the second to the fourth volution are
12, 20 and 23 degrees, respectively.
Remarks; This form is represented
only by one axial section. It somewhat
resembles the specimens described as
Triticites titicacaensis by ROBERTS in
NEWELL, CHRONIC and ROBERTS (1953, p.
182, pI. 36, figs. 19-20) and as T. aff.
titicacaensis by MAEDA, Y AMAGIW A, BEL.
LIDO and RANGEL (1974, p. 9, pI. 1, fig. 4).
However, those specimens have more distinct chomata than the present specimen.
Six original specimens of Triticites
titicacaensis described by DUNBAR and
NEWELL (1946, p. 479, pI. 11, figs. 1-6)
distinctly differs from the above mentioned specimens containing the present
one in having strongly fluted septa
throughout the shell. Therefore, the latter specimens must be excluded from
Triticites titicacaensis. The original specimens of Triticites titicacaensis were formerly transferred to the genus Schwagerinaby the strongly fluted septa (THOMPSON
and MILLER, 1949, p. 3). But the writersconsider that they may belong to thegenus Dunbarinella than the genus
Schwagerina in view of the distinct
chomata and strongly fluted septa.
Occurrence; Limestone at the south ofPampa Lobos, Chaparra area, Southwest
Peru. This form is associated with
Triticites cellamagnus, T. meeki, T. sp. A
and Durhamina? andensis n. sp.
Repository; Reg. no. NSM-MPC 1851
(National Science Museum).

Nobuo YAM AGIWA and Cesar RANGEL Z.

140

Order Rugosa MILNE-EDWARDS
and HAIME, 1850
Family Durhaminidae MINATO
and KATO, 1965
Genus Durha11lina WILSON
and LANGENHEIM, 1962

Durha11lina? andensis n. sp.
Plate 20, figs. 1-6

Corallum is compound and fasciculate.
Corallites are in contact in many points.
In transverse section, the corallites
show round to subpolygonal outlines owing to their contactness to the neighboring ones (pI. 20, figs. 4-6). Mature specimens are often more than 15.0 mm indiameter (pI. 20, fig. 1). External wall isrelatively thin. Sa pta are in two orders,major and minor, alternating, showing
more or less sinuous or nearly straight.
They show the diffuso-trabeqular or the
fibro-normal types under microscope.
Major ones are about 30 in number inmature stage (pI. 20, fig. 1), but 20 to 28
in number in early mature ones (pI. 20,
figs. 2, 4-6); they are thick in middle
part and thinner towards both ends, but
become thick at proximal end. Minor
ones are very short, sometimes lacking.

Dissepimentarium is rather narrow andgenerally arranged in pseudoherring bonedissepiments, but sometimes in concentricones and rarely in lonsdaleoid ones. It
is very narrow in early mature ones.
Inner wall is often seen around the innerpart of the dissepimentarium. In mature
stage, axial structure is cobweb structure
in shape and small in size, about 1/6 thediameter of a corallite. It is composedof a few septal lamellae, axial tabellae
and a long median plate. The septal
lamellae in contact with the major ones.
In early mature stage, the axial structure
is simple and irregular; septal lamellae
mostly unite with some major ones.
In longitudinal section, dissepimentarium is narrow and composed of globose
and elongate dissepiments with theirconvex sides inwards. Tabularium isbroad, consists of tabulae and axial structure. Tabulae are incomplete and composed mostly of long vesicles with theirconvex sides generally upwards and outwards, ascending to the axial structure.
Clinotabulae rarely present. In axial
structure, dome-like axial tabellae, edgesof septal lamellae and a median plate
are seen.
Remarks: The present form is very
similar to the species of the genus
Hel'itschioides in having tabulae composed

Explanation of Plate 19
Triticites cellamagnus THOMPSON and BISSEL
1. Axial section .................................................. x 13.0 (NSM-MPC 1844)
Figs. 2-4. Triticites sp. A
Fig. 1.

2. Axial section .................................................. x 13.0 (NSM-MPC 1845)
3. Axial section .................................................. x 13.0 (NSM-MPC 1846)
4. Sagittal section ................................................ x 13.0 (NSM-MPC 1847)
Figs. 5-7. Triticites meeki (MOLLER)
5. Axial section .................................................. x 13.0 (NSM-MPC 1848)
6. Axial section .................................................. x 13.0 (NSM-MPC 1849)
7. Sagittal section ................................................ x 13.0 (NSM-MPC 1850)
Fig. 8. Triticites sp. B
8. Axial section .................................................. x 13.0 (NSM-MPC 1851)

YAMAGIWA and RANGEL:

Late Paleozoic fossils in Peru

Plate 19

706. Late Paleozoic fossils in Peru
of vesicles with their convex sides upwards and outwards in longitudinal section. However, it may beleng to thegenus Durhamina then the genue Heritschioides in having simple axial structure
in early mature stage, narrow dissepimentarium, lonsdaleoid dissepiments andvery short minor septa. It closely resembles Durhamina? uddeni (Ross andRoss, 1963, p. 415, pI. 49, figs. 5-9; MINATO
and KATO, 1965, p. 38) in the following
characters. (1) Medium size ofcorallites.
(2) Long median plate in axial structure
in mature stage. (3) Neighboring corallites are often in contact. (4) Pseudoherring bone dissepiments present. (5) Tabulae ascending to the axial structure in
longitudinal section. However, the former
is distinguishable from the latter in having inner wall around the inner part ofthe dissepimentarium and shorter minor
septa. It is also similar to Durhamina
hessensis (Ross and Ross, 1962, p. 1175,
pI. 162, fig. 12, pI. 163, figs. 1-3, text-fig.
4L; MINATO and KATO, 1965, p. 43, pI. 1,
text-figs. 9-10) in many respects, but theformer differs from the latter in having
long median plate in axial structure andtabulae ascending to the axial structure
in longitudinal section. According to
ROWETT (1971), the species belonging to
the family Durhaminidae occurs in theLower Permian in Peru, but is not yet
described.
Occurrence: Limestone at the south ofPampa Lobos, Chaparra area, Southwest
Peru. The associated fossils are Triticites
cellamagnus, T. meeki, T. sp. A and T.
sp. B.
Repository: Reg. nos. NSM-PA 11999(holotype), 12000, 12001 (National Science
Museum).
References
BELLIDO, E. and NARVAEZ, S. (1960):

Geo-

141

logia del Cuadrangulo de Atico. Com.
Cart. Ceol Nac., vol. 1, no. 2, p. 1-59.
BRILL, K. G. (1963):
Permo-Pennsylvanianstratigraphy of western Colorado Plateau
and eastern Great Basin regions. Ceol.
Soc. America, Bull. vol. 74, p. 307-330, 1
pI., 17 figs.
CASSITY, P. E. and LANGENHEIM, R. L. (1966) :Pennsylvanian and Permian fusulinids of
the Bird Spring Group from Arrow Canyon,
Clark County, Nevada. Jour. Paleontology,
vol. 40, p. 931-968, pIs. 110-114, 6 figs.
DUNBAR, C. O. and CONDRA, G. E. (1927): The
fusulinidae of the Pennsylvanian System
in Nebraska. Nebr. Ceol. Survey, 2ndser., Bull. 2, 135 p., 15 pIs., 13 figs.
DUNBAR, C. O. and NEWELL, N. D. (1946):
Marine early Permian of the central Andesand its fusuline faunas. Amer. Jour. Sci.,
vol. 244, p. 377-402, 457-491, pIs. 1-12.
DUNBAR, C. O. and SKINNER, J. W. (1937):
Permian Fusulinidae of Texas in The
Geology of Texas. Univ. Texas, Bull.
3701, p. 517-825, pIs. 42-81, figs. 89-97.
MAEDA, S., YAMAGIWA, N., BELLIDO, E. and
RANGEL, C. (1974): Some fusulinids fromthe Copacabana Group at Ambo, Peru,
South America. Palaeontological study oj
the Andes (Ceol. Labor., Fa-c. Sci., Chiba
Univ.) ,po 1-13, pI. l.
MEEK, F. B. and HAYDEN, F. V. (1858): Remarks on the Lower Cretaceous beds ofKansas and Nebraska, together with descriptions of some new species of Carboniferous fossils from the valley of the
Kansas River. Acad. Net. Sci. Phila.,
Proc., vol. 10, p. 256-266.
MEEK, F. B. and HAYDEN, F. V. (1865): Paleontology of the Upper Missouri. Smithsonian Contr. Knowledge, vol. 14, p. 1135, pIs. 1-5.
MIl"ATO, M. and KATO, M. (1965): Durhaminidae. Jour. Fa.c. Sci., Hokkaido Univ.,
ser. 4, vol. 13, no. 1, p. 11-86, pIs. 1-5.
MOLLER, Valerian von (1879): Die Foraminiferen des russischen Kohlenkalks. Akad.
Imp. Sci. St. Petersbourg Mem., 7e ser.,vol. 27, 131 p., 7 pIs., 6 figs.
,NEWELL, N. D., CHRONIC, J. and ROBERTS,
T. G. (1953): Upper Paleozoic of Peru.

Nobuo YAMAGIWA and Cesar RANGEL Z.

142

Geol. Soc. America. Mem. 58, 276 p., 44
pis., 43 figs.
ROWETT, C. L. (1971): Paleogeography ofearly Permian Waagenophyllid and Durhaminid corals. Pacific Geology, 4, p.
31-37.
Ross, C. A. (1963): Standard Wolfcampian
Series (Permian), Glass mountains, Texas.
Geol. Soc. America, Mem. 88, 205 p., 29
pis., 11 figs.
Ross, C. A. and Ross, J. P. (1962): Pennsylvanian, Permian rugose corals, Glass
mountains, Texas. Jour. PaleontoLogy,
vol. 36, p. 1163-1188, pis. 160-163.
Ross, J. P. and Ross, C. A. (1963): Late
Paleozoic rugose corals, Glass mountains,
Texas. Jour. Paleontology, vol. 37, p.
409-420, pis. 48-50.
SABINS, F. F. and Ross, C. A. (1963): Late
Pennsylvanian-early Permian fusulinids
from southeast Arizona. Jour. Paleontology, vol. 37, p. 323-365, pis. 35-40, 4 figs.
SLADE, M. L. (1961): Pennsylvanian andPermian fusulinids of the Ferguson mountain area, Elko County, Nevada. Birgham

Young Univ. Geol. Studies, vol. 8, p. 5592, pis. 7-16, 2 figs.
STEINER, M. B. and WILLIAMS, T. E. (1968):
Fusulinidae of the Laborcita Formation(Lower Permian), Sacramento mountains,
New Mexico. Jour. Paleontology, vol. 42,
p. 51-60, pis. 11-13.
THOMPSOl':, M. L. (1954): American Wolfcampian fusulinids. Kansas Univ. Paleont.
Contr., Protozoa, art. 5, 226 p., 52 pis.,
14 figs.
THOMP';;ON, M. L., DODGE, H. W. and YOUNGQUIST, W. (1958): Fusulinids from theSublett range, Idaho. Jour. Paleontology,
vol. 32, p. 113-125, pis. 17-20, 1 fig.
THOMPSON, M. L. and MILLER, A. K. (1949):
Permian fusulinids and cephalopods fromthe vicinity of the Maracaibo basin in
northern South America. Jour. Paleontology, vol. 23, p. 1-24.
THOMPSOl\, M. L., WHEELER, H. E. and HAZZARD, J. C. (1946): Permian fusulinids ofCalifornia. Geol. Soc. America, Mem. 17,
77 p., 18 pis., 4 textfigs.

"'Iv - fl§wfifll, 7"-"1' ~~ '7:11!!1!ilGt:.:$tmi" oJ:ffllE~!JI!..@:l:I:\Q)iBfj~;!l.:to J: L1:I\IIJl'NI1t;fiI;:"?~ ,-c :~~~ft. "'Iv - fl§mffll, 7"-"1' ~~ '7 :ll!!1!ilGQ)~~ :/ ~~ p;f. A mjJl:' 7tmi" 0 J:ffllE~W.q,Q);fi1K!ff7.l' I?, ORCHAUSKI ttllffil:' J: "J -cl*~ ~nt.::fJiHfJ.jHiftJ:iBfj~;!l.:to J: L1:I\IIJl'NIft;fi-z.1Vf~ I..t.:.o -tQ)K:5*, iBfj~;!l.ft;fi c I..- -c Triticites cellamagnus, T. meeki, T. sp. A :to J: L1 T.
sp. B, :l\llJl'NIft:fi c I..- -C Durhamina ? andensis n. sp. ~§eJi!., gclli!t:¥IH!ri" 0 c :3:1<1:',
I? Q)ft:fi~~Q)~f\:7.I~W;ItEI Wolfcampian 1ltN-z. Ubi";: c -z.filfQ;m L-t.:.o
4-@l,

-tn

IIH~U!1<: • C.

RAl\GEL

Explanation of Plate 20
Figs. 1-6. Durhamina.? andensis n. sp.
1. Transverse section .............................................. x 5.0 (NSM-P A 11999a)
2. Transverse section .............................................. x 5.0 (NSM-PA 11999b)
3. Longitudinal section ............................................ x 5.0 (NSM-P A 11999c)
4. Transverse section .............................................. x 5.0 (NSM-P A 12000a)
5. Transverse section .............................................. x 5.0 (NSM-P A 12000b)
6. Transverse section .............................................. x 5.0 (NSM-P A 12001)

YAMAGIWA and RANGEL:

Late Paleozoic fossils in Peru

Plate 20

Trans. Proc. Palaeont. Soc. japan, N. S., No. 115, pp. 143-173, pis. 21-23, Sept. 30, 1979

707. STRATIGRAPHY AND OSTRACODA FROM LATE CENOZOICSTRATA OF THE OGA PENINSULA, AKITA PREFECTURE*YUTAKA OKADA
Geological Institute, University of Tokyo

Abstract. Stratigraphy: A brief geological summary of Late Cenozoic sedi·ments of the Oga Peninsula in northeast japan is given as the basis of paleontolog·
ical study. The Anden and Katanishi Formations are redefined and the wide dis·tribution of the Anden Formation is indicated. Lithological and paleontologicalevidence indicates six cycles of sedimentation within Upper Pleistocene deposits.
Each cycle consists of four units, unit·A to unit·D. Ostracoda: Individual numbersof ostracods per unit volume of sediment vary cyclically in response to lithologicchanges. The occurrence of poorly preserved carapaces is confined to the uppermost
and lowermost horizons of unit·C sediments. It is probable that some environmental
changes might have caused decalcification of those carapaces, because EDT A treat·ment of well preserved carapaces produced the state of preservation similar to thatobserved on the poorly preserved specimens. The observed species are assumed tohave belonged to shallow marine faunae because the fossil assemblages have species
in common with Recent offshore ostracod communities occurring at depths of about
25 m and 50 m, off the Oga Peninsula. The ostracod faunae characterized by cold·
water species are replaced by those containing warm· water species responding to
the cyclic sequences of lithofacies and probable environmental changes, especiallyan increase in water temperature. The degree of mixtures of communities is dis·cussed by comparing the structure of fossil assemblages with Recent communities
and assemblages. Finally, two new species, Finmarchinella hanaii and F. nealei,
are described.

tions have been made on the Pleistocene
fauna of this area. For example, KANEHARA (1942), KOTAKA (1954), and TAKAYASU (1962) treated mollusks, ASANO(1948) and TAKAYANAGI and OBA (1966)
foraminifers, and KOIZUMI (1968) diatoms.
These works contributed much toward
improving the taxonomy, paleoecology
and biostratigraphy of the Pleistocene
fauna of this area. However, they havenot paid any attention to the cyclic
sedimentation as one of the factors which
affected the composition of the fossil
assemblages. In this paper, Upper Pleisto-

Introduction
A cyclic change of environments during the glacial age must have profoundly
affected organic communities. From
this point of view, a cyclically repeatedsedimentary sequence of the Late Pleistocene age of the Oga Peninsula offers
various interesting information on theglacial age fauna, and the repetitious
fossiliferous units provide clues useful inpaleontological research. Many contribu* Received March 28, 1979; read jan. 22,
1977 at Koganei.

143

144

Y~~ta ka O K A DA

~8jill 7

0 6
~5

§

4

~3

~2

0

1

Fi g. 1. Inde x map and geological map. 1, Funakawa Formati on . 2, Kitaura Formation.
3, Wa k imo to Formation . 4, Shibika wa Forma t ion. 5, Anden Format ion. 6, Katani s hi Formation.
7, Kamp uz an Volc an ic Det r itus. 8, Kampuzan Lava .

707.

Stratigraphy and Ostracoda of Oga

cene ostracods of the Oga Peninsula arereported for the first time and their occurrences are discussed with the framework of this cyclic sedimentation.
Before going into the discussion of
ostracod fauna, a brief summary of geology, with special emphasis on the cyclic
sedimentation, will be given. The cyclicA

145

sedimentation is interpreted in this paper
quite differently from that given by KATO
and WATANABE (1976).
Geological Setting

Late Cenozoic sediments which constitute the Funakawa Group (Late Miocene•~ . "..:~~~.;:i'::~g';'~~~~:~'::~)~:f!~':::'~I"r.:;.::::",*......~.:.:.... :'::·..:·m·;.':=-~~.·~~"f~<.

cd;:::-;:'

E23 '
~,

-.

~l

c:::J '

D

~
,~-

'''-

.

Fig. 2. Cross section. 1, Kitaura Formation. 2, Wakimoto Formation. 3, Shibikawa Formation. 4, Anden Formation. 5, Katanishi Formation. The places indicated by A, 8, C, D and
E are shown in Fig. 1.
Chitani
1925.----t--- Shibikawa

ShaleFig. 3. Comparison of the stratigraphic unit boundaries established by various workers.
(1954* indicates Huzioka et al., 1954)

146

Yutaka OKADA

to Early Pleistocene) and the Shibikawa,
Anden and Katanishi Formations (Late
Pleistocene) are well exposed in the Oga
Peninsula, northeast Japan (Fig. 1). They
have long been considered a standardof reference stratigraphic section for the
Neogene on the Japan Sea side of Japan.
The Funakawa Group is characterized byfine-grained, off-shore marine sediments,
whereas the overlying formations consist
mainly of sandy sediments. In general,ostracods are rare in the Funakawa
Group, but they are abundant in theyounger formations. Since this study isconcerned primarily with ostracods, theauthor's field survey was confined mainly
to those formations younger than the
Funakawa Group.
Funakawa Group. HUZIOKA (1948,1959,1973) presented a detailed description oflithology of this group. This group includes the Onnagawa, Funakawa, Kitaura
and Wakimoto Formations in upward
sequence.
Onnagawa and Funakawa Formations.
OHASHI named and defined both of themin TOYAMA (1925). These formations are
not exposed in the studied area, except
for a small restricted exposure near Sarukawa on the north coast, where a massive grey silt intercalated with a numberof acidic fine tuff and scoriaceous tuff
beds forms an anticlinal structure trending in a N-S direction. This unit had
been considered to be a member of the
Wakimoto or Kitaura Formation (HUZIOKA, 1959, 1973) until KITAZATO (1975)
correlated it with the uppermost part of
the Funakawa Formation. In this paper,
KITAZATO'S correlation is adopted.
Kitaura Formation. The name wasgiven by TOYAMA (1925) and its definition by HUZIOKA (1973). HUZIOKA (1959)
tried to draw the upper boundary of thisformation at the horizon of the first
appearanceof GLoborotaLia
inflatad'ORBIGNY. However, since formations
in general should be defined on the basisof their lithology, the latest definition
of HUZIOKA (1973) is adopted here.
Wakimoto Formation. The name wasgiven by TOYAMA (1925), and its definition by HUZIOKA (1973). Exposures ofthis formation along the coast near
This
study

M-2
.... "1
0==
::;~

I

n

~

n
.....
r.:

get
....
0-

.....
",

....'"....<:...."'o>:"""k22::l marine~ non·marine
Fig. 4. Cycles and stratigraphic units.
A, S, C and D indicate units in the cycles.

707. Stratigraphy and Ostracoda of Oga

147

~a

/':::-;:'\'1 bDc_fb=:;jd~e

I::::w::j 9~ ::~-..:.~.

Fig. 5. Columnar sections of the Shibikawa Formation. The cycles·l to IV can be traced
on the basis of the continuity of lignite beds, one of which is accompanied with a thickpumiceous tuff bed. In cycle·lI, units and subunits of the cycle are sometimes traceable
throughout the area, though corresponding sandy sediments are thicker and composed of coarser
grains in the south than that in the north. The outcrops are along the southwest coast ofAnden (1), at two kilometers south of Anden (2), near lwakura (3), near Tayazawa (4), at
Uchigasaki (5) and from Wakimoto to Iinomori in the east of the synclinal axis (6). a, tuff.
b, medium-grained sand. c, fine-grained sand. d, silty sand. e, clay. f, lignite. g, conglomerate.

148

Yutaka OKADA

Anden reveal two diastems in a massive
siltstone at two different horizons about
60m apart. The stratigraphic significanceof these two sedimentary breaks has yet
to be fully examined in terms of sedimentation cycles.
Younger Formations. Strata overlying
the Funakawa Group are called the"Shibikawa Sand" (OHASHI, 1918, in Toy AMA, 1925) and are characterized by acyclic repetition of shallow-marine andnon-marine sediments. They are subdivided into the Shibikawa, Anden, andKatanishi Formations in upward sequence
and are separated by unconformities(Fig. 4).
Shibikawa Formation. This formation
was named by OHASHI (in TOYAMA, 1925)
and, by definition, it corresponds to
TAKA YASU'S (1962) 'lower division' of theShibikawa Formation. The type locality
was designated by HUZIOKA (1950) at acliff along the coast to the southwest ofAnden village. The formation is also
exposed in the environs of Wakimoto.
Its thickness is about 120 m at the type
locality and increases to more than 230m
near Wakimoto (Fig. 5). The Shibikawa
Formation has been considered to lie
upon the Wakimoto Formation unconformably (HUZIOKA, 1950, 59, 73, HUZIOKA
et al., 1954). However, KITAZATO (1975)
did not observe any unconformity. I could
neither observe such a distinct lithologicchange between the two formations
which would suggest the existence of astratigraphic break.
The Shibikawa
Formation is characterized by cycles ofsedimentation that will be explained indetail in the following chapter. In brief,
the formation at the type locality isdivisible into the lower 100 m of sandy
facies and upper 20 m of clayey facies,
on the basis of dominant lithology,
namely the sandy units (units-B, C and
D of cycles-I, II and III) in the lower

facies and the clayey unit (unit-A ofcycle-IV) in the upper facies. An erosional surface forming the base of cycleIV corresponds to the boundary between
these two facies. Marine mollusks which
occur abundantly in the lower sandy
facies are dominated by such cold-water
species as Glycymeris yessoensis (SowERBY), Patinopecten yessoensis (JAY), Mercenaria stimpsoni (GOULD), Spisula sachalinensis (SCHRENCK) and Notoacmea shl'enckii (LISCHKE) according to TAKA YASU
(1962).
Anden Formation. The name was given
by KITAZATO (1975). The Anden Formation as used herein includes the lower
part of the Katanishi Formation as defined/_ _ _ _ Ikm
\
\

iJ'

CJa
1··.... ··...1 b~

Fig. 6. Distribution of the Anden
Formation (a) traced by a key tuff bed (b).
Figures beside broken lines indicate theheight of the basal plane. Figures in circles
are index for Fig. 7. The locations of 5
and 6 correspond to the two adjacent outcrops shown in Fig. 8.

707. Stratigraphy and Ostracoda of Oga
by HUZIOKA et al. (1954), in addition to
the Anden Formation of KITAZATO (1975).
Its type locality was designated by KITAZATO (1975) at a clift' along the Anden
coast.
To the west of the anticlinal axis
(Fig. 6), this formation lies nearly horizontal and its base truncates clinounconform ably the underlying folded Wakimotoand Kitaura Formations. To the east of:::.

..':i:'',.:...
: : ' ..

illlIIlllIIl
lIIJ
..
CJ

'

::'::'::

12

3t§ =d 4

-

'.

~ 5

:.-:.
;

'

:':

legend..

;!:.~.};~\

the axis, the formation dips gently towards northeast and attains a thicknessof 19 m which is about twice as thick asthat in the west (Fig. 7). This structure
is evident from the distribution of alight purple tuff bed occurring at about
3 m above the basal unconformity.
HUZIOKA et al. (1954), HUZIOKA (1959,73) and KITAZATO (1975) regarded thepebble-bearing coarse-grained sand con-

~f?J

["

149

..
..

r········j...
~ :~!.!';.

.; .

6
7

:

..: ..
''.
... .....

.....

:...... :

-

**
***

CD

*

....'".......
.~

*
CD

CD

CD

d
®

.r. .....

*
®

,

.....
7

®

Fig. 7. Columnar sections of the Anden Formation. 1, tuff. 2, medium-grained sand. 3,
fine-grained sand. 4, silty sand. 5, clay. 6, lignite. 7, conglomerate. Single star, Shibikawa
Formation. Double stars, Wakimoto Formation. Triple stars, Kitaura Formation.

Y~~taka OKADA

150

tammg abundant Cl ycymeris yessoenSLS,
Mercenaria stimjJsoni, Patinopecten yessoensis, and others as a basal conglomerateof the Katanishi Formation. However, theconformable transition from the underl yin g finer sediments (i. e. silty fine-grainedsand) to the overlyin g coarser sediments(i. e. we ll sorted medium-grained sand)ma y possibly be accompanied by very
coarse sediments (i. e. pebble-bearing
coarse -grained sand) as the resu lt of someenvironm ental chan ges. This pebblebearing coarse-grained sand is a lways
found approximate ly 5 m a bove the li ght
purple fine-grained tuff bed throughout
the area. Furthermore, the well sorted
medium -g rained sand beds above thepebble-bearing sand are not lake sedime nts as previousl y asserted but marine
sediments which are indicated by marine
fossils including Clycymeris yessoensis.
A nd this bed is un co nformab ly over lain

f. s.
__ _

vvvv

tuff _

_ __

_

__

by a plant-bearing non-marine cla y bed
in the Katanishi Formation defined herein(see later). The boundary between t he
Anden and Katanishi Formations as usedin this study occurs at approximately
8 m above the base of the pebble-bearing
coarse-grained sand and corresponds toan uncon fo rmity separating the marine
sand from the non -marine clay. The
Anden Formation thus defined is underlain by the Shibikawa Formation clinounconformabl y and is unconformabl yoverlain by the non-marine Katanishi
Formation. The A nden Formation as
defi ned on the basis of exposures along
the Anden coast consists of . a lower 10 mof silty fine-grained sand intercalatedwith a light purple fine tuff bed near its
base and of an upper 10 m of a brownish
gray, fine -to-medium-grained sand. Marine mollusks are indicative of more orless wa rm wate r and include Acila in--- - -m.s.

I

K t . h· F
_ _ _ _ __',--,a anls I : clay

Anden F.

,.~:~:.

\\',..j.-... _ .. a It.
clay &"'--··f.~: i I

1- - - -- --- -- - -- j- -- --- - - - - -- em[0Shibikawa F.
I

5

t

m.s.

Fig . 8. Two adjacent outc rops showing clear ev iden ce of the unconformity at the base of
the Kata nishi Formation, near Kotokawa about 500 m southeast of An den.

707. Stratigraphy and Ostracoda of Oga
sign is (GOULD), Pecten albicans (SCHROTER),
Macoma tokyoensis MAKIY AM A, A rca pagia
tokunagai (IKEBE) and Turritella andenensis OTUKA according to TAKA YASU
(1962).
Katanishi Formation. Named by OHASHI
in TOYAMA (1925); its definition will begiven herein. The type locality was set
by KITAZATO (1975) at Unoki, 5 km eastof Anden. The formation is widely distributed to the west of Lake Hachirogata.
It lies subhorizontally and a distinct
unconformity separates this formationfrom the subjacent Anden Formation.
This unconformity is best exposed at acliff near Kotokawa located at about
500 m southeast of Anden (Fig. 8), where
the Anden Formation is eroded so deeplythat the base of the Katanishi Formation
reaches a horizon only 2 m above thebase of the Anden Formation. Thiseroded space is filled with a basal clayof the Katanishi Formation. The formation consists of a lower, carbonaceous
clay with abundant tube-like burrows (Fig.
10, left bottom) and an upper, mediumgrained sand intercalated with lenticular
beds of conglomerate. Such plant remains as Trapa and Juglans and nonmarine mollusks including Corbicula occur
in this lower clay.

Cyclic Sedimentation

The definition of each formation givenin the preceding chapter is based on
overall lithologic characters and is taking
account of the existence of an unconformity. The repetition of marine andnon-marine sequences, however, is welldisplayed in the outcrop along the northcoast near Anden, where four formations,
the Wakimoto, Shibikawa, Anden, andKatanishi, show evidence of cyclic sedimentation. It thus offers an interesting
problem of the relationship between the151

formational boundaries and the cycles ofsedimentation.
In the sequence of cyclic sedimentation, there occurs a certain kind of erosional surfaces showing clearly a depositional break such as uneven surfaces withor without burrowing by organisms, andflat surfaces resulted from the truncationof a bed lying below before the deposition of overlying strata. It is 'noteworthy
that, in the latter case, the bed below
the flat surface forms a wedge thinningin a westerly direction. Many of these
erosional surfaces do not appear to berelated to the cyclic change of lithofacies.
In this paper, boundaries of sedimentary
cycles are set provisionally at the baseof a sequence of non-marin beds. In doing so, four cycles are recognized within
the Shibikawa Formation and one in the
Anden and Katanishi Formations, respectively. Each cycle consists of thefollowing four units in upward sequence(Fig. 9):1) Unit-A
This unit consists mainly of non-marine
clay with carbonized materials. Lignite
beds about 1 m thick are intercalated
within cycles-II and III. In cycles-IV
and VI, horizons where lignite should
occur are actually represented by carbonaceous clay and in some places by athin alternation of clay and fine-grained
sand. This unit contains such freshwater molluscan shells as Corbicula aswell as seeds of Trapa, a floating plant.
Consisting of a carbonaceous clay, thisunit is clearly distinguished from theunderlying bed of fine-grained sand ineach cycle. The planes which boundthis unit from the underlying sediments
undulate with amplitude and wave-lengthof approximately 1.5 m and 4 m in cycleIV and 0.5 m and 2 m in cycle-VI.
In one case, pipe-shaped lebensspuren
are observed in unit-A of cycle-VI, theYutaka OKADA152

CYCLES
"'.

-<l
• -<l

: -<>

, -A504
-0
~

,

:-0

r~
-A03
-A04

~~f

-A06

V
-0

-0

..S65

-0
-0

:-0
:-0

-0

,:-0
-0

!-o

N
~ well:sorted_~ trough cross-bedding~ pipe-shaped~~ (gently~burrows~ medium grained sand ~ (large scale),...." well-sorted~ planar cross-bedding

fine grained sand

77A silty sand
LLLI

~ siltm•~

inclined)VI~ lebensspuren~ herringbone... dip derreasing horizon
I122:ZZI cross-bedding~ discontinuous lamination ~ thinning-out beds

1_

clay

1.. • .....1 conglomerate

I igniter=-=:J contemporaneoust.::::::::I silt fragmentstuff

1.,11 -I plant fragments

t.. moliuslan
abundanre offossils~-soosa_mpling point(with ostrarods)-<> sam~ling point(without ostracods)

Fig. 9. Cycles. Each column shows the following from left to right: formations, units,
subunits, lithology, speciality (bedding and lebensspuren etc.), changes of dip, occurrence ofmolluscs (wide band means abundant occurrence and broken lines indicate the occurrence ofmolds), and horizons of sampling for ostracods.

707.

Stmtigraphy cmel Ost1"acoela of Oga

Fig. 10. Burrows and pipe-shaped lebensspurens ill ustrated in Fig. 9.
were tak e n at the outcrops a long the Ancien coast.

uppermost cycle which correspond to the
Katanishi Formation (Figs . 9, 10 left bottom).
2) Unit-B
This unit consists of nne- to medi uI1lgrained sand characterized by numerous
lebensspuren. The transition from unitA to unit-B is abrupt in cycles-II and IV
where numerous irregularly -s haped shallow burrows penetrate the underl yin glayers to the de pth of about 2 CI1l. In
cycle-VI , unit-B is not well represented
and indisting uis hable from unit-D because of lack of lebensspuren.
Unit -B consists of the following three153

A ll photographs

subdivisions: (a ) nne-grained massive
sand, (b) fine- to medium-g rained sandwith gently inclined, trou g h-type crossbedding in which poorly developed laminations occur, a nd (c) medium-grained
sand with steeply inclined , herringbonetype cross -bedding, in which well-definedlaminations made up of laminae of pumicegrains appea r. The sand is better sorted
higher up in the section.
In c ycle-II, all three subdivisions canbe observed. In cycle-III, subdivision (a)is concealed beneath a land slide in the
An den section , bu t its presence is ascertainable in the southern area. In cycle-

154

Yutaka OKADA

IV, unit-B is represented tly an alternating sequence of wavy discontinuous clay
beds and cross-laminated sands. Thiscross-lamination, however, is so similarin scale to that of subdivision (b) ofcycles-II and III that this alternating
sequence may be subdivision (b) of unit-B.
The angular discordance at the base ofcycle-V implies the erosion of the upper
portion of the underlying cycle-IV.
The lebensspuren observed in unit-B
can be classified into three types: twotypes of pipe-shaped lebensspuren ofdifferent size and irregularly shaped burrows (Figs. 10 right, 11 II-B-c). Marine
fossils such as Pecten are rare but do
occur near the base of unit-B in cycles-II
and IV. A brackish-water fossil, Ostreasp., was found in rudaceous mud near
the base in cycle-IV. These fossils suggest that unit-B was deposited in shallow
marine conditions. This is also confirmedby the presence of the herringbone-typecross-bedding, which is typical of thetidal environment (SHROCK, 1948).
3) Unit-C
This unit consists of ill-sorted marine
sands with abundant marine fossils. The
deposit is especially well displayed incycles-II, III and V. The boundary between unit-B and unit-C is defined clearlyby the base of a rudaceous sand, which
rests on a very well sorted mediumgrained sand of unit-B. The lower horizon of this unit yields marine fossils(Bivalvia, Gastropoda, Echinoidea, Cirripedia, Ostracoda, Foraminifera, etc.).
Upwards in the sequence, marine fossils
become relatively scarce and fragmentsof carbonized material gradually become
predominant. In general, fossils are scattered in a more or less random orientation in a poorly sorted sand. Frequent
occurrences of articulated bivalves indicate autochthonous deposition. Interbedded rudaceous sands are, however,packed with fossils which are buried ina more or less chaotic fashion with somedisarticulated larger bivalves lying convex side up. This may suggest an allochthonous origin of these fossils. A
study of these mollusks is in progress(for details see SHUTO et aI., 1976). Irregularly shaped burrows and pipe-shapedlebensspuren similar to those observedin unit-B also occur in the lower horizonof unit-C together with marine fossils(Fig. 10 left top). The uppermost cycle,
cycle-VI, lacks unit-C. In view of thesedimentary cycle, massive silt of theuppermost portion of the Wakimoto
Formation may correspond to unit-C incycle-I.
4) Unit-D
This unit consists of fine- to mediumgrained sand similar to that in unit-B.
Lebensspuren are restricted to the middle
horizon. Changes of lithology from unitC to this unit are gradual in cycles-I, II
and III and are abrupt in cycle-V.
The unit-D is further divided into thefollowing four subdivisions in upward
sequence: (a) fine-grained sand, weakly
laminated, often containing penecontemporaneous silt fragments, (b) fine- tomedium-grained sand characterized by thetrough-type cross-bedding, (c) mediumgrained sand, characterized by the herringbone-type cross-bedding, (d) wellsorted medium-grained sand, evenly laminated with individual laminae lying generally horizontal or sometimes slightly
inclined (Fig. 11, I-D-d and II-D-d). Evenly
laminated sand beds of the near-shore
environment are explained by REINECK
and SINGH (1973) as indicative of accumulation often encountered on beaches justabove the high water line. In general,sands of these subdivisions are better
sorted higher up in the sequence. The
basal part of the Shibikawa Formation
below cycle-II corresponds to unit-D in

707.

Stratigraphy and Ostracoda of Oga

155

F ig. 11. Cross-bedding illustrated in units-B and D of Cyc les-I and II in Fig. 9. The upper
two pho tog raphs (-d) sho w even laminae wit h indi v idua l la yers usu a ll y horizontal or sometimes
slight ly inclined. The t wo bottom photographs (-c) displa y herrin gbone-t ype cross-bedding.
In II-D-d , the length of the pickax hel ve is 43 cm. In I-D-d, the hammer hel ve is 28 cm. In
I-D-c, th e rod is 30 cm. In II-B-c, the sca le on the helve indi ca tes 10 cm . The photograp hs
w ere taken at the correspond ing ho r izo ns in the cyc les in the outcrops along the southwest
coast of Anden .

cycle-I.
All the subdi visions of unit-D can beobserved in cycles-! and II. The t hi cknessof subdivision (a) tends to decrease upwa rd from cycle-I to cycle-III. Subdi vision (a) is not well represented in cy cleV and subdivisions Cc) and Cd) seem tohave been eroded away in cycles-III andV.
Pipe-sha ped burrows of different sizes
are observa ble in subdi vision Cb). Poorly
preserved moulds of mollusks and echi-noids occur in cycle-V, suggestin g a low
possibilit y of preserva tion of organic
remains in these sandy units. In fact,
fossi ls are generall y very rare in theseunits. In exceptional cases in the same
hori zon, however, mollusks bearing wellpreserved color pattern are found in an
outcrop about 300 m south of Anden, andsuggest a relati vely short period of thesubjection of shells to abrasion . F urthermore, the occurrence of Sp isula sachalinensis has so far been con fin ed within

156

Yutaka OKADA

this horizon. The abpve evidence seems
to eliminate the possibility that thesefossils were derived from lower horizons.
5) Conclusion
From the foregoing description of thecyclic sedimentation, the following remarks can be made:1. Cycle-I represents only the late regressive phase of one cycle, the earlytransgre~sive phase being masked in themassive silt bed of the Wakimoto Formation, deposited exclusively in deep marine
environments. It is possible that thebase of the cycle may be represented bya diastem found in the Wakimoto Formation.
2. The marine facies, which is typically represented by unit-C and possibly
includes a major part of units-B and D,
tends to decrease in thickness in upward
sequence, while the non-marine facies represented by unit-A is thicker in cyclesIV and VI than that in cycles-II and III.
Furthermore, all the successive units
from A to D and their subdivisions arepreserved fully only in the lower cycles
and are partly missing from the upper
cycles.
3. Those units which are absent froma given cycle fall within unconformablesurfaces in the cyclic sequence. Thesesurfaces can be classified into the following two categories: (1) surfaces formedin the phase of inundation by the sea.
A stable stand of sea level for a certain
period of time may be inferred from thedevelopment of an extensive abrasion
platform. The base of unit-C in cycle-V,
which also truncates the inclined Wakimoto and Kitaura Formations, represents
this category in having an extensive
horizontal erosion surface. It is likelythat the seaward extension of this surface merges into relatively off-shore
sediments such as unit-C of cycles-II and
III. The unit-C of these lower cycles

contains many horizons presumably interrupting sedimentary continuity, namely,
the basal surfaces of coarser sediments
which are separated sharply from finer
sediments lying below, surfaces with burrows excavated by organisms, and surfaces with a combination of both features.
In other words, the landward extensionof these relatively off-shore sedimentsof unit-C might possibly be correlatedwith terrace deposits now lying higher
than the plane of the Anden Formationin the west of the anticlinal axis. (2)Surfaces formed during a regression.
The base of unit-A of cycles-IV and VI,
formed after the erosion of a considerable thickness of the underlying sediments, falls in this category.
4. The upper two incomplete cycles,
cycles-V and VI, whose upper and lower
limits are bounded by unconformities,
correspond directly to the Anden andKatanishi Formations, respectively. The
upper boundary of the Shibikawa Formation, however, is defined by an unconformity and its lower boundary by aconformable lithological transition. Thus,in general, formational boundaries which
are based primarily on differences inoverall lithology do not always correspond to boundaries between cycles.
5. There has been a controversy as towhether the transgressions and regressions inferred from the cyclic sedimentsof the Oga Peninsula were caused byeustatic sea-level changes or by local
tectonic movements. The dip of theformations decrea~es upwards from theShibikawa Formation to the Katanishi
Formation. The stepwise reduction of
dip of strata is well demonstrated along
the Anden coast. The dip suddenly
decreases, at the unconformity at thebase of the Anden Formation, at the discordant planes indicated by solid triangles
in Fig. 9, and probably in cross-laminated707. Stratigraphy and Ostracoda oj Oga
beds where the angle of dip lessens between the base and top of each bed (indicated by zigzag lines in Fig. 9). Thesehorizons occur independently of thecyclic change of lithofacies, though someof these horizons may have been misunderstood to interpret cycles and used
to correlate arbitrarily with glacial cycles
by KATO and WATANABE (1976). Furthermore, the amount of tilting is notequal in different horizons and localities,
and the direction of tilting varies fromplace to place. In conclusion, there is noobservable correlation between the cyclic
sedimentation and the stepwise reductionof dip of strata. The Shibikawa, Andenand Katanishi Formations seem to reflect
the up and down movements of sea level aswell as local tectonic movements whichwere independent from glacioeustatic
sea-level changes.

157

n-&

i7 .•
n~ i~

Iicl

Ostracod Fauna
Stratigraphic horizons from which
ostracod samples were collected are indicated in Fig. 9. The sample preparation
employed in this study is detailed by
IKEYA (1971c). For a comparative study,
Recent materials were dredged fromseveral stations off the Oga Peninsula
using an OCKELMANN type sampler, modified by HANAI in order to obtain semiquantitative samples. The sampler was
designed to dredge a veneer of sedimentsof about 1 cm in thickness just below thewater-sediment interface, and over an
area of approximately 1 m 2 (5 m X 0.2 m).
Sampling stations are shown in Fig. 12.
For the identification of ostracod taxa,
references were made to HANAI (1957a,
1957b, 1957c, 1959a, 1959b, 1970), ISHIZAKI(1966, 1968, 1971), NEALE (1974), and
NEALE and HOWE (1975).
1) Abundance of fossil ostracods
As shown in Figs. 9 and 13, ostracods.

m'2

Fig. 12. Sampling stations off Oga
Peninsula for Recent ostracods.

are nearly exclusively confined to unit-C
in the cycles of sedimentation. The
number of ostracods per one cubic centimeter of sediments varies verticallywithin each unit-C, that is, it reaches amaximum near the middle of unit-C andthen decreases upwards. In general, theYutaka OKADA

158

C I Sam.ple Sandyc e numDer ratio

~.~
V
[!]
ill

II

A 79
A03
A04
A05
A 81
A 71
A06

e

{

565
551
548
546
545
544
543
542
541
540
537
528
527
526
524
521
517
516
513
5 9
5 5
5 3
5 1

Abundance(Oensity) Preservation Numberof ostracods,Nicc stateof I
individua s

•

?

0
0
0
0
0
0

•
e

1}
o~-

g

...
c::>

0
0
0
0
0
0
0
0

e

••

0
0
0
0
0
0
0
0
0

e

0
c::>

178
170
224
238
145
802
274
243
8
160
193
135
245
329
185
274
213
502
154
175
341
271
665
551
300
350
173
187
216
265
5

wello
ill.

Fig. 13. Vertical changes of ostracod faunae (1) and sand ratio.

abundance of ostracods changes cyclicallyin accordance with lithological changes.
The ratio of sand fraction per unit
volume of sediments is shown in Fig. 13.
There is a tendency that the density of
ostracods shifts in an inverse relation to
the sand ratio throughout the sequence.
2) State of preservation
The state of preservation of fossil
ostracods is not the same in all the horizons. Under the binocular microscope,carapaces show two types of appearance:
one having a glossy surface showing
sculpture clearly and the other with amilky surface showing sculpture obscurely. Most of the specimens fromsamples S-27, 28, 65 and 79 have a milky
surface. Both types of preservation arefound in samples S-I, 37, 51 and A-504.
The remaining samples contain ostracods
with a glossy surface showing clearly
defined sculpture. In order to clarify thedifferences of preservation, Cythere lutea
with a glossy carapace from sample S-16
and that with a milky carapace fromsamples S-27 and 28 were examined bymeans of SEM (scanning electron microscope). Those carapaces with a milky
surface (sample S-28) have a more roughand granular appearance than thosewith a glossy surface (sample S-16) (Fig.
14, PI. 21, Figs. 1, 2). This observationagrees well with that made by OERTLI(1975). Fine structures such as the surface pits and sieve plates of normal pore
canals are hardly preserved in the specimens from sample S-27 and 28. Observations of fractured carapaces from sample
S-28 revealed that the thin outer layer(epicuticle) is not clear due to decomposition, and that calcite grains of the middle
layer (pro cuticle) are more sparse thanthose of glossy surface specimens (PI. 21,
Figs. 4, 7, 8).

707.

Stratigraphy and Ostracoda of Oga

F ig. 14. Di ffe rent state of preservationof ca ra pa ce surface of Cythere iutea. Co mpare the microstructures of t he surface andno rmal pore cana ls, large pores a nd small
pores . a: Re ce nt s pecim en. b: we ll pre served f ossi l. c: poorl y preserved fossi llost its si eve plate. Sca le 10,l1m.

The surface of a g lossy carapace fromsample S-16, afte r bein g decalcifi ed in asolution of neutralized 0.1 M EDTA for
45 seconds, sho wed an appearance similar
to that of the milk y carapaces from159

samples S-27 and 28 (PI. 21, Figs. 5, 6).
Decalcification of the carapaces of Ii ving
Cythere iutea by EDTA resulted in a very
different appearance (PI. 21 , Fig. 3) owing
to the presence of a stiff outer layer(epicuticle) which might have protected
the carapace from the solution of calcite.
Therefore, the poorly preserved carapaces
are inferred to have been subjected todecalcification after the outer la yer was
decomposed .
It is interesting to note that the occurrence of poorly preser ved carapaces isconfined to the uppermost and lo wermost
horizons of unit-C sediment. Some environmental change seems to have influenced the state of preservation there.
3) Relation of faunal changes to thecyclesAs shown in Table 1, ostracod faunasin these cyc les are dominated by coldwater genera, and, in generic composition, they somewhat resemble the highlatitude marine ostracod faunae of NEA LE
and HOWE (1975). F ig. 15 shows a vertical change in the frequenc y of indi viduals belonging to the genera Baf/inicy theTeand "UTocythereis" which are known tobe distributed in the A rctic Ocean andits nei ghboring areas.
The verticalchange in the total frequency of indi viduals of the cold-water genera including
Bafjinicy there, "UTocythereis" F inmarchinella, Hemicy there, Howeina, Mun seyella,
Schizocythere and Semicytherura, which
are kno w n to be distributed mainl y inhi gh latitud e areas, is also presented in
Fi g. 15. The frequency of most of thesecold-wa ter inhabitants te nds to decreasein higher stratigraphic hori zons. A ccording to NEALE (1974), F inmarchinella
anguiata (SA RS) ranges geographi ca ll yfrom about 50' no rth lati t ude in the
A tl a ntic to the A rctic Ocean. This
species also decreases up wards a nd ismainly confined to the lowe r two cycles.

Yutaka OKADA

160
C-cle Sample Very cold'J
numberNumber01 COld
species

Cold

7

A 504

5

5
6
7
7

A05
A 81
A 71

12

A06
565

9

551
548
546
545
544
543
542
541
540
537

13

8
11
10
10
10
11
12
10

m

:n:

--

6

A79

V A03
A 04

[!]

Warm

F. a.

12
17

528
527
526
524
521
517
516
513

17
14
14
16
14
13
13
13

5 9
5 5
5 3
5

___

15

1
,-00'0N
I:)....co

en
co

...,
co

,-0
0'

-

co

Fig. 15. Vertical changes of ostracod faunae (2). Ratio of individuals belonging to BajJinicy.
there and "Urocythereis" (Very cold) ; to B ajJin icy there, "Urocythereis", Finmarchinella, Hemicy.
there, Howeina, Munseyella, Schizocythere, and Semicytherura (Cold) ; to Finmarchinella angulata(F. a.) ; to Loxoconcha optima, Cytheromorpha acupunctata, Proteoconcha tomokoae, Trachyleberis
scabrocuneata, Echinocythereis bradyformis, and Ruggieria bisanensis (Warm). The bar indicatesthe range of 95% confidence.

In contra5t to the cold-water species,
seven species which are known to inhabit
warm current areas near Japan today
occur nearly exclusively in the uppermost
cycle. They are Loxoconcha optima ISHIZAKI, Cythero11lorpha acu punctata (BRADY),
Proteoconcha tomokoae (ISHIZAKI), Tra-

chyleberis scabrocuneata(BRADY), Echinocythereis brady/ormis ISHIZAKI, and Ruggieria bisanensis (OKUBO). Therefore, thefaunae characterized by cold-water species were replaced by those comprising
warm-water species in the cyclic sequenceof lithofacies.
Recent ostracods inhabiting depths
ranging from 25 m to 800 m off the Oga

Peninsula were dredged (Fig. 12). The
fossil assemblages were found to haveseveral species in common with themodern ostracod communities living at
depths of about 25 m and 50 m (Table 1).
Therefore, the observed species in thesecycles are interpreted to have lived inshallow seas not deeper than 50 m, andthe range of sea level fluctuations mightalso have been confined within thisdepth.
Throughout the cycles, the number offossil species in common with the Recent
ostracod fauna living at a depth of 25 m
is nearly equal to that at 50 m. So it isdifficult to conclude that the environment

707. Stratigraphy and Ostracoda of Oga

161

Table 1. Faunal list of ostracods.

Pectoc,Ytht'rc pscudoamphidonta
m CI'ocythcl'Ul'U

• 1 1

~p.

Scmicythcl'ura Icptocythcl'oldca
I1cmicytherc SJle•
~ll1nscyella hukkui donna

A

1 2 1
·0

• 1

Cythcf'ura sp.H

1 ••Ilo",cion cnmptocytheroidca
Raffinicythcl'c sp.n
Uuffinicythcl'C Sfl.elJl'ocythcrc i::; sp. A

8GG557G
1 1 1:)
I;
2 2 G

<)

~llInseyclla Iwtntatcllsi::;=3 5 5 9 ;; :! :3 1 • • 2
Callistocythcl'c sctancllsi:o'::! 6 ·1 '1 ;:; 1 :2 1 1 ... 2
Calli stocythcl'e undulat i Cue iul is 101012 9 1 !j :3 2. t)
Seh ~7.ocythcrc okhotskcn:·;i s
9 8 913HH:)I417122lJ 1DOSem.lcythcl'lIl'u hCI1l·yhow~i.

Bo :~~~~~~~h~~I~~n;::~~~~:~~~!S
Raffinicythcl'c "'p.A
Baffinicythcl'c ,.;p.O
FinmaJ'chinclln ungulatu
Ii'inmal'chinelln nealei
Ll'Ilcy1.hcl'cis ~()I'okuen~is
IIcmicytlwl'j dm.- sp.

1 •5 3 ·12 1 "1 I; 1 5 :) G ;;H~

~1~ ~ ~ ~ ~l~ ~ ~ ~l~
9 8 " ;:; 1 <I • 1 • • 5
G 114 ;:;.3:")
5 7 ;; ~ 5 1 3 -I 5 718
G ~ 2 :! 1 2:) :3 7 :3;:) ~ (i ·1 :) H .., 2 ,1 fi
7 8 6 2 5 ,I ~ ,I :311

sp.A
Cushmanidca spoil
Call istocytht'I'c suh,juponi Cit
C SpinUchcl'js sp.
OCythcl'ul'u ~poA

1 1 1 1 1 1
1 - 2 1

f; 9 7 2 5

5 ;;
:2 ;;
2;'11
1
1 ;;

OLoxncuncha upt i ma
Loxoconcha SfioA
li'inmul'chillclla hUlIlli i
AudIa ~p.H
CO,"lucllcl'in<1 ~Jl.
cOTr'uchy1chcl'j S :o;cnhl'oCllllcalu
Coqll imba spo
C,. . ., ,,.,
1 1

·1

1

4

3

~

"

~

·1

1

2
3 2 3
,I 1
1 5 3
5

... .,

1

1 G

1 1

1 1

1 1
1

1 7

1
(j

2. lj 11 I:!

L

511 HI'I 1

11173{j::;22<14;;:i·I~·I:;'1:) 1 .1 1
.. 1

10 ,I

* 1

::! :3 1

::; 1
1

1

1
1

3

1

., 2

1 ~
2

1

" ". - "
~

.,

2
1
1 1

3

1
1
1

2

-

1
1

.

" '10 7 1 910
0'I 1 3 8 7
1 1 ;; 1 1 17
3 5
1!) 1 :!
1 1 1 •H U12 ·1 3 <1:!11
319
II:! (j 8 8 ·1 2 1'1920 918:!S:)63110::; -I 5 (j :3 ·1 5 5

:)

::;

110;J:.! 2 1

1

* 1 1

11

, .,

, - ., " .

,I::;"

1 1;:) 8 5 ;:).,5 ,I1 "

1

., 1

1

1
1 ·1

G

,

.,2 11 ::;2 2

1 7 310 2

.

5

., "1

., 3

.,

1

r,

. "-., , -COCII~hmallidca

C ~ g;~~~;~~~~~~~;:~ ~::~r<il;~~~~~

7

~

,

1 5 1

Schizocytht,!,c sp.

o O~~:l~~~~~;:~!:h~o;~~~~~~~clata

1 "" 323

OI'~ehinoc~·thcl'c i s Iwmlyful'mi:..:Ru~gicril.l hi:..:nnt'nsis

P"racY'H'i!'l S(lo\"eonesidca 8p.
COCythcl'c Iutt'nPaijcnho)'chcl1a mi IIPcn~ i ~o Pai.jcnhol'chclla tdanglllal'is
Loxoconcha sp oil
OOLoxoconcha ~poC
luxoconcha ~p D
Am'Ua ;;;p •.4.
Co,'nucoqll imha mnnil\'cnsi s
IIcl'mnlli tcs ~Jl.
Tr'ach~'lehcri di dac sp_o Bythoccl'at inn hanui i.
O:Xcstoleberls ...;p.A

E

1

:! J

1 :; 1.

2 1
.)

1

.,
~

.

.,1 1I; .,1

1 1
211

.,

.,J ·1 ~

1

.,

0

1
J.

.,

;;

9
f; J

·1

., 1

.

~

1

.

1 1

.)

~

., 1

~Jl2.1Hl1

7;-;;)
1 2.

HJ(;}O G

7:)412·:;:),) L 2 :)

• 1
1

1
1 1

1

·1

.
,

1 22. 4:.! Ii. .,1
3 1 ;;;;

1'I f; Ii 7 ·1
1 *10
1

1

-

.,

Cllshmnnidca spoC
l~lIe:,·thcl~csp.

OOCythcrc ,japon'j en
Pnlmcllclln limi('olaP,wacythcl'idcn spo
Cythcrura sp.C
C;ythcl'lIl~a "p.D
CythCl'optCl'Oll sp.A
OC~·thCI·uptcl'nn

F~JI. B
Loxoc(lI'nicullllll kotOI'l.Il'(U'UIIIIII
Cythcl'omor'pha "'po
1i1~oc~·thcl'ci.,;;
COJ~llllC()ctllimhi.l

J'

sp.1l
sp_

lIil'~lItocythel'c n07.okicl1si~b. Acanthocytht"'l.·i ssp.
Bllntonin ~p 0 A

1

BlIntonia !O;Jl.1l
Xc~tolcbcds sp.B
Xc,.;tolcbcl'is :..:p.C
Xcstolcbcl'lS spoD
COCrthcrois sp.
SClCl'ochilus sp.

.,1

• 1

1 • 1

1 •
1 1

1 ••

1 1

Figures indicate the ratio of each species within a sample in percent, and * indicates existence of species less than 0.5 percent. The SEM photographs of all species are shown in
OKADA (1977). Species found in Recent sea, at the depth of 25m(O), 50m(D), and 75m(.6.)
are also shown. The cycle numbers are indicated by II, 1II and V, beside of which sample
numbers are shown. The species are classified into six types: A) species mostly confined to
the lowest cycle, B) species gradually decreasing in individual numbers towards upper levels,C) species gradually increasing in individual numbers upwards, D) species confined to the uppermost cycle, E) species without any particular tendency in stratigraphic distribution, andF) species too rare to show any tendency.

162

Yutaka OKADAof the upper cycle was significantly
different in depth from that of the lower
cycle.
The distribution pattern of a typicalcold-water species, Baffinicythere sp. maygive us information about the change ofwater temperature. According to HAZEL(1970), the maximum depth in which living B. emarginata (SARS) can be founddecreases equatorwards from 200 m to
38 m as the species is probably governed
by winter bottom temperatures lower
than about 5°C which are needed for reproduction. So the disappearance of suchcold-water species as B. sp. throughout
the sediment column may indicate anincrease in bottom water temperatureduring winter time greater than the low
winter temperature needed for reproduction of the species. Furthermore, verticalchanges of water temperature at depths
less than 50 m are not significant, whencompared with the extent of seasonalchanges (Central Meteorological Observatory, 1967-1969).
In conclusion, the gradual changes of
ostracod faunae as mentioned above areprobably not the direct result of changes
in the depth of seas. It is very likelythat the average sea-water temperature,especially in winter, rose from lower
cycles to upper cycles.
In terms of stratigraphic occurrences,
the species can be classified into the following six types (Table 1): A) species
mostly confined to the lowest cycle, B)
species gradually decreasing in numbers
towards higher stratigraphic levels, C)
species gradually increasing in individual
numbers upwards, D) species confined tothe uppermost cycle, E) species without
any particular tendency in stratigraphic
distribution, and F) species too rare toshow any particular tendency.
The distribution of some species listed
in Table 1 is known, while the geograph-

ic ranges of other species have as yet
to be determined. The results as described above, however, may become
useful in estimating their geographic
ranges, because these four groups (fromA to D) are considered to have originatedfrom their differing temperature preference.
For example, the range ofFinmarchineLLa hanaii n. sp. would be
different from that of F. nealei n. sp.
which would be similar to that of F.
angulata.
Howeina higashimeyaensis ISHIZAKI exhibits morphologic variations and therelative abundance of different morphotypes changes through the sequence,
especially from one cycle to another andalso at some horizons within unit-C where
rudaceous silty sands are succeeded byrather massive silty sands. This poses
many interesting paleontological problems.
4) Structure of ostracod assemblages
There are many studies on the structure of Recent communities and fossil
assemblages; e. g. on fossil lake chydorids(Cladocera) by WHITESIDE and HARMSWORTH (1967) and TSUKADA (1967), on
Recent marine benthonic foraminifers by
BUZAS and GIBSON (1969) and IKEY A (1970,
1971a, 1971b), and on Recent marine decapods by ABELE (1974). It is well known
that the structure of a community depends
upon its surrounding environment. Investigation of the structure of fossil assemblages is said to be useful in obtaining information on environmental
changes.
The structure of fossil assemblages isshown in Fig. 17. Numbers of individualsof each species are plotted in log scaleon the ordinate, against respective species
in the sequence from the most to theleast abundant, on the abscissa. Most
assemblages are arranged non-linearly,
each line consisting of a steeper segment

707. Stratigraphy and Ostracoda of Oga

163

100

•o

o

O:c=O.~B

10

.

00

0

1-2
Q:c=O.55

o •

10

..
0

0

0

.......

.. ...

ill-:!
-G2111o0. ....

0 0 - - -_ _ __•••••••........ .
..

ll-2
-52m
.:c=O.ll
O:c=O.410'--------_ 0...

.:c=0.09
0:c=0.-19---------

o

-'IBm

o

-30m

•

0

.:c=O.30

o 0

ill-I

... .c».

o • • • • • '--_ _ _ _ _ _ _

1
100

..

H-l
-25m
.:c=0 • .30

I-I
-203m
e:c=O.56
0:c=0.61

e:c=().25• Q:c=O.25

o •••• ' - - - - _ 0 0 • • • •

..
100

10

o 0

H-5

H-4

H-3
-75,"

-100m

.:c=0.16
0:c=0.15.:c=O.l10:c=0.15

•o •

..
o 0

•

' - -_ _ _ _ _ 0

0

•

•

•

• •

L·:·. ·
0

0

0

<!85m
.:c=0.26
0:c=().~9

11-7

n-fi

-8:20me:c=O • .:)5-520m.:c=O.4B
0:c=O.40

Q:c=O.72

1
0

0

..

.. ....
0•' - -_ _ _ _ _ __o.

0Fig. 16. The structure of Recent living communities (0) and total assemblages (e).
Numbers of individuals of each species in log scale on the ordinate. Species sequence fromthe most to least abundant on the abscissa.

and a more gently declining segment.
The inclination of the latter is nearly
constant at most horizons. The steeper
segment is readily identifiable at somehorizons but cannot be easily recognizedat others. The inclination of the lines,
which as a whole represents the diversityof the samples, is much lower than thatof reported communities of living animals.
This is also shown by extremely highvalues of divf'rsity index H' (Fig. 18).
The conspicuousness of steeper segments
can be expressed by the index of concentration c=~(ndN)2 of SIMPSON (1949),
where N is total number of individuals

in an assemblage and nt is the numberof individuals of i'th species in the sequence. Then the value of c shows significant changes through the cycles (Fig.
18). In cycle-II, c remains very low. On
the contrary, c often rises to higher
value in cycles-III and V. This suggests
the environment of cycles-III and V differsfrom that of cycle-II.
According to IKEY A'S (1970) study on
Recent foraminifers, total assemblage
which consists of living and dead foraminifers is arranged in a bent line when it
is a mixture of different communities.
The same may be said of the Recent

Yutaka OKADA

164.. ...
..
S-28· •.....
\ ......
.....
..
'"
..
... ..
'. ' .......
.
......
.
. " ...
........ .....
.......
.....
.....
~ .~:48 ... ...... \ A-;cil•S-2~········.. .... .
-......:::.. ~ .....
.. .~:-;; ... :::::.........
'"\". ....... .
.-.
........
... ...... -.... .... ....... .
A~·;3········.
'. ..
...... .
.............. ....... . \ ...... ..... ... .......
-. .....
......•.... ~. .. ...... .
.... .... e. ...
S-16·····.
......
' .. ...
....... ............... . ..... ... ........
......... .
.'.
\...........
.
.
8-42·· ••••• ......
.....
... ..... .. ..... ...... . " ......
...........' ..
..
.......
......
..
........
........
8-40··.
...............
A-7t······ .......
............ .............. \ ..
.....
..
' ..
.......
' .......
'. .......
S-3
5-37 ••••
S-27 •••••••••••

S-5•••••••••
I
••••

\

\.

8-26 ••••••-,- 21

••

8-17

'\

••••• _.

••••••••\

S-46••••••

5-45••••••••••

8-44

•••••

8-43

e

•••••

8-13 •••••••••

S- 9 •••••••-.. 8- 4 1 ••••••••

S-S··· •••

100
10

1

1

~--------------------

....

A-04

••••

A-OS

••••••••

A-81

•••

A-06

••••••••••\.J....______________ • ••••••••••

II

III

v

Fig. 17. The structure of fossil assemblages. Numbers of individuals of each species on
the ordinate. Species sequence from the most to least abundant on the abscissa. Scale markson the ordinate also indicate the origin of the samples. Forming gentle slopes by dots, every
assemblage shows high diversity. When the steeper segment of a bent line is conspicuous,
their marginal dots are connected by a straight line to clarify the steepness. II, III and V
correspond to cycle numbers.

ostracod samples off the Oga Peninsula(Fig. 16). Good examples are II-2 andIII-I from shallow marine environment.
Each of the living communities fits ontoa straight line, whereas the respective
total assemblages deviate considerablyfrom the lines. In II-2, owing to theaddition of dead ostracods from different
communities to the living community at
the place, the total assemblage becomesarranged in a sharply bent line. In III-I,
because of extreme mixing of deadostracod carapaces, the steeper segment
is no longer obvious and the inclinationof the line becomes quite gentle. In
other samples, resulting from the additionof fewer dead ostracods, the total assemblages retain low diversity.
Therefore, the sharply bent lines andthe high diversity of the fossil assemblages probably resulted from mixing
of communities. Obscureness of steeper
segments may reflect the degree of mixing. IKEY A (1970, p. 186) considered assemblages to be "a sum of successive
generations of living populations adapted
respectively to such environmental fluctuations as seasonal and annual, and fur-

707. Stratigraphy and Ostracoda of Oga

165

Ratio oflarva ratio
Fjnmarchinella hanaii sp.nov. of I..!!..
A5Q4

178

23

A 79

170

30
28
31
30
36
41
32

V AA03
04
A 05

145

A 71

A06

802
274
243

565

8

551
548
546
545
544
543
542
541
540
537

160
193
135

A 81

IWl
ill

224
238

528
527
526

245
329
185

274
213
502

154
175

341

524

271
665
551

516

300
350
173

IT 517
521
513
5 9
5 5
5 3
5 1

187
216
265
5

2B

36
23
32
36
27
34
25
40
30
20
29
36
42
46
34

32
29
29
25
27
,0

0'

N

=

°~c.J'1= g-

Fig. 18. Vertical changes of ostracod faunae (3). The values of diversity index (H') areconstantly high. The conspicuousness of steeper segments (in Fig. 17) is expressed by theindex of concentration (c). N is total number of individuals in an assemblage and ni is thenumber of individuals of i'th species in the sequence.

ther modified by transportation of deadtests by currents". In other words, themixture is expected to occur in an unstable environment and/or in a violent environment with high transportation energy. So the change in value of c in thefossil assemblages may suggest that theenvironment became more or less stable
and/or mild towards upper cycles.
Both shapes and size are different between larval valves and adult ones ofFinmal'chineila hanaii n. sp., which is thedominant species through cycles-III and
V. So possibly they may have been
moved independently by the sorting
agent. The ratio of the larvae to total
number of valves of F. hanaii is almost
c'onstant and does not show any correlation with the value of c. So it would
be difficult to confirm the idea that thesteeper segments (in Fig. 17) depend on
the species which were concentrated by

Yutaka OKADA

166

sorting effect. Furthermore, no significant correlation was observed between
the value of c and the sand ratio of therespective samples. This result also
stands against the idea.
The dominant species through eachcycle are Schizocythere okhotskensis HANAI, Howeina higashimeyaensis and Callistocythere undulatifacialis HANAI in thelowest cycle, Finmarchinella hanaii and
Aurila sp. A in the middle cycle, andFinmarchinella hanaii and Cytheropteronsawanense HANAI in the uppermost cycle.
The middle and the upper cycles resemble
each other with regard to dominant
species. This may mean that the environment of cycle-III resembled more that ofcycle-V than that of cycle-II. The dominant species itself frequently changes
within the lowest cycle, which may indicate the instability of the environment.
In cycles-III and V, it remains unchanged
throughout unit-C except for the lowest
and uppermost horizons. This fact, together with the value of c, suggests thatthe environment became more stable fromthe lower cycle to the upper cycles.
Systematic Descriptions
Depository and Abbreviations.-Holotypes and paratypes are deposited in thecollection of the University Museum,
University of Tokyo (UMUT), Japan.
Numbers of these specimens are prefixed
CA for Cenozoic Arthropoda.
The following abbreviations are usedin the systematic section:
S: Sex (M for male and F for female)
Sp: Specimen measured (L, R, C forleft valve, right valve, carapace)
Me: Measurement in mm (L for length,
H for height, W for width)
N: Number of observations
X: Arithmetic means: Standard deviation

V: Coefficient of variation
a: Coefficient of regression of reduced
major axis
OR: Observed range
Order Podocopida SARS, 1866
Superfamily Cytheracea BAIRD, 1850
Family Hemicytheridae PURl, 1953
Subfamily Hemicytherinae PURl, 1953
Genus Finmarchinella SWAIN, 1963
Subgenus Barentsovia NEALE, 1974

Finmarchinella (Barentsovia)
hanaii sp. nov.
PI. 22, Figs. 1-13

Diagnosis.-A species of Finmarchinella(Barentsovia) with weak anterior marginal ridge, notched caudal process, crescentposterodorsal rib and overall reticulation.
Reticulation weak, consisting of shallow
polygonal fossae surrounded by fine muri
and accompanied with second-order reticulation. Hinge line arches abruptly
near anterior and posterior terminals.
Description.- Valves in lateral viewrounded-rectangular of typical Finmarchinella shape. Anterior margin round,
dorsal margin straight in male andscarcely convex in female, posterodorsal
margin angularly convex, posterior margin protruding into a caudal process with
two weak notches. In dorsal view rounded, subhexagonal. Eye tubercle and subcentral tubercle well-developed. Anterior
marginal ridge weak. Ornamentation of
overall reticulation consisting of polygonal fossae with second-order reticulation and accented by a rib developed inposterodorsal area. Fossae very shallow,
often obscure and surrounded by finemuri. The rib runs posteriorly near

707. Stratigraphy and Ostracoda of Oga
dorsal margin from about two-thirds ofthe length of the valve, curves ventrally
at about five-sixths of the length, andends at about two-thirds of the height.
There are two weak nodes near anterior
margin at about two-thirds and one-thirdof the height. The upper node is connected with an eye tubercle by a shortridge in right valve, separated In left
valve. Hinge merodont, 5-6 teeth inanterior and posterior hinge area respectively. The anteriormost and posteriormost teeth are largest and scarcely
separated from adjacent teeth, near which
hinge line curves ventrally, while theother teeth are clearly separated fromeach other. Normal pore canals consistTable 2.
S

Sp

Me

F

L

L

H

Cycle

N

IT

14
41
23
14
41
23
21
56
17
21
56
17

V
IT
][

R

L

V
IT
][

R

H

V
IT
][

V
C
M

L

w

][

L

V
IT

H

V
][

5

V
IT
][

R

L

V
IT
][

V
R

H

IT
][

C

w

7
1

20
32
26
20
32
26
15
30
25
15
30
25

][

L

ing of large and small pores. Large one
sieve type either with or without anapparent setal opening. Small pore withsecluded obscure inner structure. Marginal pore canals nearly straight without
branching; approximately 45 anteriorly
and 15 posteriorly. Anterior and posterior
vestibules narrow. Muscle scar patterntypical of the genus consisting of a vertical row of four adductor scars withthree scars anteriorly. The middle two
adductor scars quite clearly divided.
Sexual dimorphism marked, the males
being lower, in proportion to their length,than the females. Juvenile forms shoW
more prominent tubercles and ridges, andnarrower vestibules.
IS

Measurements (in mm) of F. hanaii from cycles·I1, III and V.

][

L

167

s

V

OR

O. 714
O. 737
0.713
0.361
0.379
0.367
O. 720O. 728
O. 702
0.356
0.367
0.355
0.370

0.01840.02320.02200.01360.01280.01080.02830.02640.02180.01500.01260.0124

2.58
3.15
3.08
3. 75
3.39
2.95
3.93
3.63
3.10
4.21
3.42
3.50

0.630
0.634
0.615
0.297
0.298
0.295
0.611
0.640
0.607
0.281
0.297
0.285
0.3:>20.01750.01940.01690.01230.00990.00890.02330.01790.01970.0129
0.OQ730.0090

2. 77
3.05
2. 75
4.14
3.33
3.00
3.82
2. 79
3.24
4.59

0.68-0.74
0.69-0.79
0.66-0.75
0.33-0.38
0.35-0.40
0.34-0.39
0.66-0.76
0.66-0.77
0.65-0.74
0.33-0.38
0.33-0.40
0.33-0.37
0.35-0.39
0.37
0.59-0.66
0.60-0.67
0.59-0.66
0.28-0.33
0.28-0.31
0.28-0.32
0.55-0.65
0.61-0.69
0.56-0.64
0.24-0.30
0.28-0.31
0.27-0.31
0.29-0.31

'1045

3.16

O. 737
0.553
0.492

0.530
0.475
0.571

O. 704
0.513
0.524

0.552
0.407
0.457

Yutaka OKADA

168

Affinities and Differences.-This species
is most closely related to F. (B.) angulata.
Both species lack any rib connecting theventral end of the posterodorsal rib withthe subcentral tubercle. It is easily differentiated from F. (B.) angulata by the
weak anterior marginal ridge, shallow
fossae and fine muri. In dorsal view its
outline is more rounded and smooththan F. (B.) angulata. Hinge line isclearly curved near its margins and teethof anterior and posterior hinge area areclearly separated in this species, whereasin F. (B.) anguiata from the Oga Peninsula,
hinge line is almost straight at theanterior margin of the hinge.
Types.-Holotype, UMUT-CA 9614, a
left valve (PI. 22, Fig. 2); Figured paratypes, UMUT -CA 9615-9626.
Occurrence.- This species occurs fromall the horizons of cycles-II, III, V aslisted in Table 1. The ratio of numberof individuals within each sample increases towards upper horizons.
Finmarchinella (Barentsovia)
nealei sp. nov.
PI. 23, Figs. 1-5

Diagnosis.-A species of Finmarchinella(Barentsovia) with a well-developed anterior marginal ridge, weak posterodorsal
rib, and overall reticulation. Its ventrolateral surface hangs downward in sucha manner to hide the posterior part ofthe ventral contact margin in lateralview. Hinge line gently arches near theanterior margin.
Description.-In lateral view, valvesrounded-rectangular having a typicalFinmarchinella shape. Anterior marginround, dorsal margin slightly concave inmales and barely convex in females,
posterodorsal margin gently convex, posterior margin protruded a little by arather smooth caudal process. Ventrolateral surface hanging downward to hideposterior part of ventral contact marginat about three-fourths of the length,
where the carapace bulges most. In dorsal
view rounded subhexagonal. Eye tubercles well-developed and subcentral tubercle gently convex. Anterior marginal
ridge well developed. Ornamentation of
overall reticulation consisting of finely
pitted round fossae and weak costation.
A weak rib runs posteriorly near dorsal
margin from about the middle of the valve

Explanation of Plate 21
Fig. 1. Cythere lutea from sample S·16. Lateral view of male right valve. An example of wellpreserved fossil ostracod. x 89.
Fig. 2. Cythere lutea from sample S·27. Lateral view of male right valve. An example ofpoorly preserved fossil ostracod. x 89.
Figs. 3-8. Structure of the carapace of Cythere lutea, shown by fractured samples.
3. Recent sample from the Hayama Beach with EDT A treatment. x 1300.
4. Well preserved fossil from sample S·16 without EDT A treatment. x 1400.
5-6. Well preserved fossils from sample S·16, with EDT A treatment. 5: x 1300. 6: x 1400.
7-8. Poorly preserved fossils from sample S·28, without EDT A treatment. 7: x 1450. 8:x 1400.
c: procuticie consists of many calcite granules. de: denatured (fossilized) epicuticie. di:denatured inner membraneous layer. dis: denatured inner membraneous layer at sieve plate.
ep: epicuticie. im: inner membraneous layer. lp: large normal pore canal with sieve plate.
os: outer surface. p: pit. s: small normal pore canal without sieve plate. sp: sieve platewith numerous pores. st: seta.

OKADA:

Stratigraphy and Ostracoda in Oga

Plate 21

707.

Stratigraphy and Ostracoda of Oga

length, curves ventrally at about fivesixths of the length, where it is most prominent, and becomes obscure at about twothirds of the height. Hinge antimerodont,
5-6 teeth in anterior and posterior hinge
areas respectively, anteriormost and posteriormost teeth are largest. The first,
forth, and fifth teeth from the posterior
end are subdivided into two tooth lets.
Anteriormost tooth and its adjacent tooth
are also subdivided. Each tooth andtooth let is separated merely at the dorsal
side. Hinge line arches gently at anterior
hinge area and curves abruptly near posterior end. Normal pore canals consisting of large sieve-type pores either withor without an apparent setal opening,and small pores with secluded obscure
inner structure. Marginal pore canals
Table 3.
Sp

Me

F

L

L

Cycle

N

II

24
11

][

H

V
II
][

R

L

R

H

C

?vI

L
L

w
L

H

V
II
ill
V
II

L

H

4

24
15

V
II

1
4

][

4

II

9

][

6
9

II
II
V
II
][

V

s

v

OR

0.675
0.679
0.658
0.373
0.373
0.362
0.675
0.682

0.02810.03940.01300.01950.02340.00830.02330.0410

4.17
5.80
1. 98
5.22
6.28
2.29
3.45
6.01

0.368
0.372

0.01180.0256

3.20
6.89

0.360
0.373
0.589
0.580
0.306
0.312
0.590
0.570

0.01200.02080.00680.0121

2.03
3.59
2.24
3.89

0.63-0.74
0.63-0.75
0.65-0.68
0.34-0.41
0.33-0.41
0.35-0.37
0.64-0.74
0.62-0.73
0.67
0.35-0.40
0.34-0.41
0.36
0.34-0.38
0.33-0.39
0.57-0.61
0.56-0.62
0.30-0.32
0.29-0.32
0.57-0.61
0.56-0.58
0.57
0.29-0.31
0.28-0.30
0.30

1

][

][

R

4

24
11

24
15

][

R

nearly straight without branching; approximately 40 anteriorly and 25 posteriorly, concentrated anteroventrally.
Anterior and posterior vestibules narrow.
Muscle scars consisting of a vertical row
of four adductor scars with two apparent
scars. anteriorly. The middle two adductor scars are very clearly divided.
Sexual dimorphism marked, the males
being lower, in proportion to their length,than the females.
Affinities and Diffeernces.-This species
is closely related to F. (B.) angulata. Bothspecies lack any rib connecting the ventral end of the posterodorsal rib with thesubcentral tubercle. It is easily differentiated from F. (B.) angulata by the weakcentral tubercle, the lack of posterior
node and downwards hanging ventro-

Measurements (in mm) of F. (B.) nec.lei from cycles-II, III and V.

S

L

169

6
4
2
1
4

2
1

0.303
0.290

0.947
0.949
0.522

o. 788
0.980

0.482
0.264

170

Yutaka OKADA

lateral surface. In dorsal view, its outline
is more smooth than that of F. (B.)
angulata. Hinge line near anterior margin
curves gently in this species, whereas it isalmost straight in F. (B.) angulata. The
ribs of this species are so weak that it
seems also to be related to F. (Finmarchinella) finmarchica (SARS). It is, however, easily differentiated from F. (F.)
finmarchica by the existence of a rib anda well-developed anterior marginal ridge.
In lateral view, F. (B.) nealei is very
similar to Hem icy there nana SCHORNIKOV,
though H. nana has amphidont type hinge,
weaker anterior marginal ridge, and morerounded outline.
Types.-Holotype, UMUT-CA 9627, aleft valve (PI. 23, Fig. 1); Figured paratypes, UMUT -CA 9628-9631.
Occurrence.- This species occurs fromalmost all the horizons of cycles-II, III, V
listed in Table 1. The ratio within eachsample decreases towards upper horizons.
Acknowledgments

I wish to express my deep gratitude
to Professor Tetsuro HANAI of the Geological Institute, University of Tokyo,
under whose direction this study was
carried out. I would like to also express
my appreciation to Drs. Kiyotaka CHINZEI and Itaru HAY AMI of the Universityof Tokyo, Noriyuki IKEYA of the Shizuoka University, Yasuhide IWASAKI of the
Kumamoto University, Tomowo OZAWA
and Toshiyuki YAMAGUCHI of the University of Tokyo for their instructions during laboratory and field works. Messrs.
Norimasa NISHIDA and Katsumi ABE
kindly assisted in various ways. I thankto Mr. Paul FRYDL for reading English.
Deep gratitude is also expressed to Dr.
J. A. GRANT-MACKIE of the Geology De-

Explanation of Plate 22
Figs. 1-13. Finmarchinella (Barentsovia) hanaii OKADA, n. sp., from sample S-45.
All figures x 78 unless otherwise stated.
1. Female right valve (Paratype, CA 9615).
2. Female left valve (Holotype, CA 9614).
3. Male right valve (Paratype, CA 9616).
a. External lateral view.
b. External view of large normal pore canal with sieve plate and setal opening. x 1700.
c. External view of small normal pore canal. x 3500.
4. Male left valve (Paratype, CA 9617).
5. Larval instar, right valve (Para type, CA 9618).
6. Larval instar, left valve (Paratype, CA 9619).
7. Male right valve (Para type, CA 9620).
8. Female right valve (Para type, CA 9621).
a. Internal lateral view.
b. Anterior part of hinge. x 205.
c. Posterior part of hinge. x 205.
d. Adductor muscle scars with three scars anteriorly. x 260.
9. Larval instar, right valve (Paratype, CA 9622).
10. Male complete carapace (Para type, CA 9623).
11. Female complete carapace (Para type, CA 9624).
12. Larval instar, complete carapace (Paratype, CA 9625).
13. Anterior marginal area of female left valve (Paratype, CA 9626), showing radial pores.
x 118.

OKADA: Stratigraphy and Ostracoda in Oga

Plate 22

707. Stratigraphy and Ostracoda of Ogapartment, University of Auckland, Auckland, New Zealand for reading the manuscript and encouragement. lowe verymuch the improvement of this manuscript
to Dr. Kunihiro ISHIZAKI of the Tohoku
University and Professor Tsunemasa
SAITO of the Yamagata University.
Recent materials from the sea off the
Oga Peninsula were collected on board
the R/V "Tansei-maru" of the Ocean
Research Institute, University of Tokyo.
Photographs of ostracods were taken by
a scanning electron microscope of Hitachi HSM-2.
References
ABELE, L. G. (1974): Species diversity of
decapod crustaceans in marine habitats.
Ecology, vol. 55, no. 1, p. 156-16!.
ASANO, K. (1948): Foraminiferal zonation of
the Wakimoto and Shibikawa Formations..
Oga Peninsula, Akita Prefecture, as astandard subdivision of the japanese
Pliocene of the boderland of the japan Sea.
J. Ceol. Soc. Jap., vol. 54, no. 631-633, p.
44-49. (in japanese with English abstract)
BuZAs, M. A., and GIBSON, T. G. (1969):
Species diversity: Benthonic foraminifera
in western North Atlantic. Science, vol.
163, p. 72-75.
Central Meteorological Observatory. (19671969): The result of marine meteorological and oceanographical observations. (injapanese)
CHlTANI, Y. (1925): The geology of the
Ogashima Oil Field, Prefecture of Akita.
Geol. Surv. lap. 16pp., i-iii. (in japanesewith English abstract)
HANAI, T. (1957a): Studies on the Ostracoda
from japan, I. Subfamily Leptocytherinae,
n. subfam. J. Pac. Sci. Univ. Tokyo, sec.
2, vol. 10, pt. 3, p. 431-468, pIs. 7-10.
- - (1957b): Studies on the Ostracoda fromjapan, II. Subfamily Pectocytherinae, n.
subfam. J. Pac. Sci. Univ. Tokyo, sec. 2,
vol. 10, pt. 3, p. 469~482, pI. 11.
- - (1957c): Studies on the Ostracoda fromjapan, III. Subfamilies Cytherurinae G. W.

171

MULLER (emend, G. O. SARS 1925) andCytheropterinae n. subfam. J. Pac. Sci.
Univ. Tokyo, sec. 2, vol. 11, pt. 1, p. 1136, pIs. 2-4.
- - (1959a): Studies on the Ostracoda fromjapan, IV. Family Cytherideidae SARS,
1925. J. Pac. Sci. Univ. Tokyo, sec. 2,
vol. 11, pt. 3, p. 291-308, pIs. 16-18.
- - (1959b): Studies on the Ostracoda fromjapan, V. Subfamily Cytherinae DANA, 1852
(emend.). J. Pac. Sci. Univ. Tokyo, sec.
2, vol. 11, pt. 4, p. 409-418, pI. 28.
- - (1970): Studies on the ostracod subfamily
Schizocytherinae MANDELSTAM. J. Paleon·
tol., vol. 44, no. 4, p. 693-729, pIs. 107,108.
- - , IKEYA, N., ISHIZAKI, K., SEKIGUCI-I1, Y.
and YA)IMA, M. (1977): Checklist ofOstracoda from japan and its adjacentseas. Univ. Mus. Univ. Tokyo, Bull., no.
12, 120pp., pIs. 1-4.
HAZEL, j. E. (1970): Atlantic continental
shelf and slope of the United Statesostracode zoogeography in the southern
Nova Scotian and northern Virginian
faunal provinces. U. S. Ceol. Surv. Prof.
Pap. 529.E, p. E1·E21, pIs. 1-69.
HuzloKA, K. (1948): Oga Peninsular Series.
J. Ceol. Soc. Jap., vol. 54, no. 638, p. 145146. (in japanese)- - (1950): Stratigraphy and Structure ofTertiary Deposits in Oga Peninsula, Akita
Prefecture. Jap. Assoc. Petrol. Technol.
J., vol. 15, p. 116-126. (in japanese withEnglish abstract)- - (1959): Explanatory text of the geolog·
ical map of japan, Scale 1: 50000, Togaand Funakawa. Geol. Surv. jap., 61pp. (injapanese)- - (1973): Geology of Oga Peninsula, Akita
Prefecture, japan. Rep., Nat. Conserv.
Soc. Jap., no. 44, p. 5-34. (in japanese)- - , INOUE, T., TAKAYASU, T., KA:-1o, H.,
HONDA, S. and KANO, T. (1954): Oga
Peninsula. (Guide book for geologicalsurvey). Geol. Soc. lap. (Akita Branch),30pp. (in japanese)
IKEY A, N. (1970): Population ecology ofbenthonic Foraminifera in Ishikari Bay,
Hokkaido, japan. Rec. Oceanogr. Works

172

Yutaka OKADA

lap., vol. 10, no. 2, p. 173-191.
- - (1971a): Species diversity of benthonicForaminifera, off the Shimokita Peninsula,
Pacific coast of north Japan. Rec. Oceanogr.
Works lap., vol. 11, no. 1, p. 27-37.
- - (1971b): Species diversity of Recent
benthonic foraminifera off the Pacificcoast of north Japan. Rep. Fcc. Sci.,
Shizuoka Univ., vol. 6, p. 179-201.
- - (1971c):
Sampling and preparation
method for fossil and Recent Foraminifera.
Mater., Ceol. Soc. Shizuoka, no. 21, p. 131. (in Japanese)
ISHIZAKI, K. (1966): Miocene and Pliocene
ostracodes from the Sendai area, Japan.
Tohoku Univ., Sci. Rep. 2nd ser. (Geol.),
vol. 37, no. 2, p. 131-163, pIs. 16-19.
- - (1968): Ostracodes from Uranouchi Bay,
Kochi Prefecture, Japan. Tohoku Univ.,
Sci. Rep. 2nd. ser. (Geol.), vol. 40, no. 1,
p. 1-45, pis. 1-9.
- - (1971): Ostracodes from Aomori Bay,
Aomori Prefecture, Northeast Honshu,
Japan. Tohoku Univ., Sci. Rep. 2nd ser.
(Geol.), vol. 43, no. 1, p. 59-97, pIs. 1-7.
KANEHARA, K. (1942): Fossil mollusca from
Tayazawa, Wakimoto-mura, Katanishi oilfield. l. Ceol. Soc. lap., vol. 49, no. 581,
p. 76-78, pI. 3 (2). (in Japanese)
KATO, M. and WATANABE, A. (1976): On
geologic structure and the depositional
condition of the Pleistocene deposits at

the Anden coast, Oga Peninsula, Northeast
Japan. Sci. Rep., Akita Mus, no. 1, p.
56-65. (in Japanese with English summary)
KITAZATO, H. (1975): Geology and Geochronology of the Younger Cenozoic of Oga
Peninsula. Tohoku Univ. Inst. Ceol.
Paleontol., Contrib., no. 75, p. 17-49. (inJapanese with English abstract)
KOlZUMI, I. (1968): Tertiary diatom flora of
Oga Peninsula, Akita Prefecture, Northeast
Japan. Tohoku Univ., Sci. Rep. 2nd. ser.
(Geol.), vol. 40, no. 3, p. 171-240, pIs. 3235.
KOTAKA, T. (1954): Turritella zonules in
the Pliocene deposits of Akita (Studies
on the fossil moIlucsa from the Neogene
deposits of Northeast Japan). Saito Hoon-Kuj Mus. Res. Bull., no. 23, p. 8-10.
(in Japanese with English abstract)
NEALE, J. W. (1974): The genus Finmarchinella S\\"AIN 1963 (Crustacea, Ostracoda)
and its species. Bull. Brit. Mus. Nat.
Hist. (Zool.), vol. 27, no. 2, p. 89-93, pIs.
1, 2.
- - and HOWE, H. V. (1975): The marine
Ostracoda of Russian Harbour, Novaya
Zemlya and other high latitude faunas.
Bull. Am. Paleontol., vol. 65, p. 381-431.
OERTLl, H. J. (1975): The conservation of
ostracode tests-observations made under
the scanning electron microscope. BUll.

Explanation of Plate 23
Figs. 1-5. Finmarchinella (Barentsovia) nealei OKADA, n. sp., from sample S-24.
a. External lateral view. x 88.
b. Internal lateral view. x 76.
c. External dorsal view. ,<76.
d. Anterior part of hinge. x 220.
e. Posterior part of hinge. x 220.
f. External view of large normal pore canal with sieve plate and setal opening. x 2600.
g. External view of large and small pore canals. x 1200.
h. Adductor muscle scars with two scars anteriorly. x 350.
1. Female left valve (Holotype, CA 9627).
2. Female right valve (Paratype, CA 9628).
3. Male left -valve (Para type, CA 9629).
4. Male right valve (Para type, CA 9630).
5. Female left valve (Para type, CA 9631). Anterior marginal area showing radial pores.
x 118.

OKADA: Stratigraphy and Ostracoda in Oga

Plate 23

707. Stratigraphy and Ostracoda of Oga
Am. Paleontol., vol. 65, p. 549-575.
OHASHI, R. (1930): Geology of Oga Peninsula.
l. Ceol. Soc. lap., vol. 37, no. 443, p. 740754. (in Japanese)
OKADA, Y. (1977MS):
Stratigraphy and
Ostracoda of the Younger Cenozoic in the
Oga Peninsula, Ak~ia Prefecture. 61pp.,
17pls. (Master Thesis)
REINECK, H. -E. and SINGH, I. B. (1973): Depositional Sedimentary Environments.
Springer-Verlag; Berlin; 439pp;
SHROCK, R. R. (1948): Sequence in layered
Rocks. McGraw-Hill, New York, 507pp.
SIMPSON, E. H. (1949): Measurement of diversity. Nature, vol. 163, p. 688.
SHUTO, T. et al. (1976): Survey of Oga
Peninsula. Commun. Pap. Molluscan Res.
Croup, p. 9-33. (in Japanese)
TAKAHASHI, J. (1940): The sedimentary
cycles in Oga Series (II). l. lap. Assoc.
Petrol. Mineral. Econ. Ceol. vol. 23, no.
5, p. 194-203. (in Japanese)
TAKAYANAGI, Y. and OSA, T. (1966): Stratigraphic change and significance of planktonic Foraminifera from the Oga Peninsula.
l. Ceol. Soc. lap., vol. 72, no. 1, p. 35-47.
(in Japanese with English abstract)
TAKAYASU, T. (1962): Molluscan fossils fromthe Shibikawa Formation in the Oga

Peninsula, Akita Prefecture, Japan. l.
Min. Coli. Akita Univ. ser. A, vol. 2, no.
2, p. 1-19.
TOYAMA, S. (1925): Tertiary deposits in Oga
Peninsula, Akita Prefecture. Hokko, no.
20, p. 56-71. (in Japanese)
TSUKADA, M. (1967): Fossil Cladocera inLake Nojiri and ecological order. Quaternary Res., vol. 6, no. 3, p. 101-110.
(in Japanese with English abstract)
WHITESIDE, M. C. and HARMSWORTH, R. V.
(1967): Species diversity in chydorid(Cladocera) communities. Ecology, vol.
48, no. 4, p. 664-667.
YAMANOI, T. (1978): Neogene pollen stratigraphy of the Oga Peninsula, Northeast
Honshu, Japan. l. Ceol. Soc. lap.,- vol.
84, no. 2, p. 69-86, pl. 1.
Postscript: Recently, YAMANOI (1978)
reported to have confirmed the unconformity
with vast time gap between the Wakimotoand Shibikawa Formations by examining pollen. However, because most samples weretaken from non-marine sediments in the Shibikawa Formation, and from marine sedimentsin the lower formations, the pollen evidencecannot be regarded as conclusive.

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Transactions and Proceedings of the PalaeontologicalSociety of Japan

September 30, 1979

New Series No. 115

CONTENTS
TRANSACTIONS
705. SHUTO, Tsugio and SHIRAISHI, Shigeyoshi: A L~wer Miocene Ichnofaunaof the Middle Ashiya Group, North Kyushu -Ichnological Study of the
Ashiya Group-I- . . ..... .... . .. . . . . . . .. . . . .. . . . ...... . . . . . . . ... .. .. . . 109
706. Y AMAGIWA, Nobuo and RANGEL, Z. Cesar: Some Interesting Fossils fromthe Upper Paleozoic in Chaparra Area, Southwest Peru ... . ..... ... . . 135
707. OKADA, Yutaka: Stratigraphy and Ostracoda from Late Cenozoic Strataof the Oga Peninsula, Akita Prefecture . .. ........ . .... .. . . . .... . . . .. 143