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Chapter 20. A preliminary study on ornamentation and ultrastructure of Mesozoic and Cenozoic Ostracoda in China
236 Y.T.Hou AND Y. H. ZHAO
ostracod shell was started in the later of 1970’s. The junior author, in his master thesis (1981)
and his doctoral dissertation (1984) (both in press), described shape of pore canals of some
ostracods, established five types of ultrastructure of carapace, and discussed the relationship
between the trace elements in shell and the palaeoenvironment, in which the ostracods once lived.
Recently greater attention has been paid by Chinese ostracod researchers to shell ornamentation and pore ultrastructure of ostracods collected in China. This paper deals with a large
TABLETYPES OF OSTRACOD ORNAMENTATION
A. Reticulate type
1. Polygonal reticulate type
2. Granular ridge-like reticulate type
3. Transverse bar-bearing reticulate type
4. Polyform reticulate type
5. Round reticulate type
6. Scale-like reticulate type
C. Echinulate type
1. Spine-like echinulate type
2. Granular echinulate type
D. Striate type
1. Corduroy-like striate type
2. Fingerprint-like striate type
B. Spot-shaped type
1. Punctate ornamented type
2. Measles-like ornamented type
TABLET TYPES OF OSTRACOD
A. Types of simple pores
1. Single circular pores
2. Double circular pores
3. Lip-like circular pores
4. Funnel-shaped circular pores
B. Types of sieve pores
1. Round sieve pores
2. Elongate or irregular sieve pores
amount of material which has been studied by many Chinese ostracod workers and published
in the past thirty-odd years. The present writers make use of the holotypes and homotypes described and illustrated in these publications, amounting to more than 500 species and nearly 1,OOO
individuals of Mesozoic and Cenozoic non-marine or marine Ostracoda, which were examined by
means of the scanningelectron microscope. From several thousand scanning electron microphotographs they observed that the ornamentation of the shell and the ultrastructure of the pores show
many patterns and consider that both kinds of patterns may be divided into twelve and six types
respectively (see Tables 1 and 2).
1. Limnocytherenodosa Bojie, Polygonal reticulate ornamentation, Bar=lO pm. Fig. 2. Paracandona
euplectella (Robertson), Granular ridge-like reticulate ornamentation, Bar = 10 pm. Fig. 3. Limnocythere
bucerusu Sou, Transverse bar-bearing reticulate ornamentation, Bar = 100 pm. Fig. 4. Leucocythereplena
Y.H. Zhao, Polyform reticulate ornamentation, Bar = 10 pm. Fig. 5. Cypridea favosa Ye, Round reticulate
ornamentation, Bar = 100 pm. Fig. 6. Cypridea? dissonu Netchaeva, Scale-like reticulate ornamentation,
Bar = 100 p m . Fig. 7 . Camarocypris ovata Bojie, Punctate ornamentation, Bar = 30 pm. Fig. 8 . Sinocypris
funingemis Ho, Measles-like ornamentation, Bar = 100 pm.
Ornamentation and Ultrastructure of Ostracoda in China 239
1. Polygonal reticulate type, with surface ornamentation composed of polygonal reticulation.
Meshes very shallow and flat, as in some species of the genera Limnocythere, Chinocythere and
Ilyocypris. especially clear in Limnocythere bicostata Bojie, L. microcostata Bojie, L. longipileiformis Bojie, L. nodosa Bojie, L . dectyophora Bajie (Pl. 1, fig. 1).
2. Granular ridge-like reticulate type, possesses reticulateridges consistingof many micrograins
arranged in regular order; reticulation generally appearing in pentagonal or hexagonal shapes
as in Paracandona euplectella (Robertson) (Pl. I , fig. 2).
3. Transverse bar-bearing reticulate type, with meshes rather irregular, rhomboidal, hexagonal
or sub-quadrate in shape and unequal in size; each mesh with a transverse bar, which may be longer or shorter, as in Limnocypridea bucerrusa Sou, L. inflata Ye and Ilyocyprimorpha netchaevae
s u (Pl. 1, fig. 3).
4. Polyform reticulate type, bearing a lot of secondary ornamentation in the shape of
five-pointed stars or six to seven or three to four round pits in each irregular reticulate mesh, as
shown on the surface of Limnocythere (Xinanolimnocythere) tribulosa Y.H. Zhao, Leucocythere
plena Y.H. Zhao and Abrotocythere quadracornis Y.H. Zhao (Pl. 1, fig. 4).
5. Round reticulate type, with round meshes spreading all over the surface, sometimes slightly
oblong in shape, often varying in size and area between adjacent meshes. All these features are usually
observable in genera such as Cypridea, Ilyocyprimorpha, Limnocypridea, Huabeinia, Quadracypris,
Talicypridea, etc., and occasionally in a few species belonging to the genera Tuozhuangia and Chinocythere. Species which are considered to show the typical ornamentation include Cypridea bella
Chen, C. favosa Ye, C. fuyuensis Ding, C . (Cypridea) semimorula Chen, C . (C.) cellularia Chen,
Ilyocyprimorpha magnijica Liu, Z. sungarienensis Ten, Limnocypridea datongzhenensis Ye,
Huabeinia huidongensis Bojie, H. postideclivis Bojie, Tuozhuangia alispinata Bojie, Chinocythere
xinzhenensis Bojie, etc. (PI. 1, fig. 5).
6 Scale-like reticulate type, ornamented with scale-shaped reticulation arranged densely on
the surface and observable in such species as Cypridea? dissona Netchaeva (Pl. 1, fig. 6).
1. Punctate ornamented type, with many punctate pits over the whole surface of the valves,
with Camarocypris elliptica Bojie, C. ovata Bojie as representatives of this pattern (Pl. 1, fig. 7).
2. Measles-like ornamented type, shell surface completely covered by a number of very small
round punctuations. Sinocytheridea latiovata Hou et Chen, S. longa Hou et Chen and Sinocypris
funingensis Ho are representative (Pl. 1, fig. 8) of this type.
1. Spine-like echinulate type, with a great number of small spines distributed over the surface;
2-Fig. 1. Dongyingiu impofitaBojie, Spine-like echinulate ornamentation, Bar = 30 pm. Fig. 2. Cyprideo
(Sebastianites) tumidu Ho, Granular echinulate ornamentation, Bar = 100 pm. Fig. 3. Ziziphocypris rugosu
(Liu). Corduroy-likestriate ornamentation, Bar = 100 pm. Fig. 4. Berocypris substriatuBojie, Fingerprint-like
striate ornamentation, Bar = 30 pm. Fig. 5. Metacypris aphthosa Y.H. Zhao, Single circular pore, Bar = 1
pm. Fig. 6. Cypridopsis caohaiensis Y.H. Zhao, Double circular pore, Bar = 1 pm. Fig. 7. Ilyocypris neoaspera
Huang, Lip-like circular pore, Bar = 10 pm. Fig. 8. Candonu dafiensisHuang, Funnel-shaped circular pore,
Bar = 1 pm. Fig. 9. Cythere futeu futeuO.F. Muller, Round sieve pore, Bar = 10 pm. Fig. 10. C'ushrnunidea
japonica Hanai, Elongate or irregular sieve pore, Bar = 10 pm.
Y.T.HOU AND Y.H. ZHAO
Dongyingia impolita Bojie and Ilyocyprimorpha inandita are representative of this pattern (PI. 2,
2. Granular echinulate type, decorated with many small grain-like tubercules over the whole
surface, with Cypridea (Sebastianites) tumida Ho as the typical example (Pl. 2, fig. 2).
1. Corduroy-like striate type, with curved, continuous and disconnected striations present on
the surface, as observed in the non-marine species Ziziphocypris rugosa (Liu), 2 . simakovi (Mandelstam) and the marine species Perissocytheridea trapeziformis Hou et Chen, as far as known
(Pl. 2, fig. 3).
2. Fingerprint-like striate type, bearing curved striations rather like fingerprints, sometimes
branching or with two merging into one; distance between two striae unequal-as shown on the
surface of Berocypris substriata Bojie, B. striata Bojie and Virgatocypris striata Bojie (Pl. 2, fig. 4).
Types of simple pores
1. Single circular pores. Pores round in shape, simple, and evenly distributed; size and space
between pores variable in different genera and species, usually found on the surface of many ostracod species collected from non-marine strata in China, with Candona and Metacypris as very
typical patterns (Pl. 2, fig. 5).
2. Double circular pores. Pores appearing doubly-circular in form, connected with one another around a common centre, as in Cypridopsis caohaiensis Y.H. Zhao and Cyclocypris persicaria
Y.H. Zhao (Pl. 2, fig. 6).
3. Lip-like circular pores. Pores appear to have a collar-like flange under high magnification,
quite commonly occurring in non-marine ostracod species observed under the SEM, as in Chinocythere, Limnocythere, Ilyocypris, etc. (Pl. 2, fig. 7).
4. Funnel-shaped circular pores. Pores on the surface appear somewhat funnel-like. and are
only found in a few non-marine ostracod species, such as Candona daliensis Huang (Pl. 2, fig. 8).
Types of sieve pores
1. Round sieve pores. Pores circular in shape, with a large one in the centre or near the
margin but absent in a few species; different in size and arrangement with different species and genera. So far only found in marine ostracods such as Perissocytheridea trapeziformis Hou et Chen,
Neocytherideis convexa Hou et Chen, Sinocytheridea latiovata Hou et Chen, S. longa Hou et Chen,
Chthere lutea lutea. O.F. Muller, Eucythere sp., etc. (Pl. 2, fig. 9).
2. Elongate or irregular sieve pores. Pores appearing elongate or irregular in shape, often
in association with circular sieve pores on the same shell surface, as in Cushmanideajaponica Hanai
(Pl. 2, fig. 10).
Summing up all the types of ornamentation and pore ultrastructure mentioned above, the writers
here put forward their preliminary views:
1. Types of surface ornamentation can be similar to each other in different species of the same
genus or of different genera.
Ornamentation and Ultrastructure of Ostracoda in China 241
2. Although some fossil ostracods can be found in different sedimentary conditions in different
areas, their ornamentations bear obvious similarities to each other.
3. In general, similar ornamentation may occur in different species of the same genus distributed in different geological ages. For example, the geological range of Limnocythere is from
Tertiary to Recent, but the ornamentation of different species in this genus is commonly polygonal
reticulate. On the other hand, a close relationship exists between some species of Cypridea and
some species of Talicypridea or Quadracypris, both of which possess the same kind of ornamentation belonging to the round-pit reticulate type.
4. Although the type of ornamentation varies in different parts of the same shell surface, as
seen in Limnocypridea succinata Ding and Neocytherideis convexa Hou et Chen, the variation is
stable in different individuals of the same species, as in Limnocythere (Xianolimnocythere) trilubosa
Y.H. Zhao and Abrotocythere quadracornis Y.H. Zhao.
5. Types of pores are obviously different between Ostracoda collected from marine strata and
from non-marine strata. They are probably not influenced by the type of ornamentation, but may
be controlled by sedimentary facies, or more specifically, by salinity.
From a macroscopic view, it seems that the variation in ostracod ornamentation is not controlled
by the factors of time and space, but possibly caused by some factors in the organism itself. Preliminary assessment of the large amount of material described in this paper reveals that there is
probably a close relationship between the character of ostracod ornamentation and their evolution and therefore the study of shell ornamentation would provide evidence not only for evolutionary affinity, but also for their classification. It is especially significant in dealing with the problems of ostracod classification and evolution. The results of observations on the samples suggest
that the different pore types are closely linked with sedimentary conditions such as salinity, etc., SO
the type of pore can be considered as one of the indicators for determining the sedimentary facies
and conditions under which the ostracod lived.
To sum up, the type of ostracod ornamentation may reflect the relationship between some
genera and their evolutionary processes,while the type of pore is probably related to the sedimentary
facies. The study of both these features would accumulate more material and evidence leading to a
much wider field for ostracod researchers in the future.
We wish to express our thanks to Mr. Yuan Liu-ping for technical assistance and to our colleagues who supplied homotypes.
D ~ P ~ ~ C HP.E1982.
Ultrastructure of the wall
of two living ostracods,Herpetocypris chevreuxi (Sars) and Pontocythere
elonguta (Brady), in comparison with fossil ostracods from the Middle Jurassic of Normandy. I n BATE, R.H.,
ROBINSON, E. and SHEPPARD, L.M. (eds.). Fossil and Recent Ostracods, 61-74. Ellis Horwood Ltd. Publishers, Chi-
HANAI, T. 1970. Studies on the ostracod subfamily Schizocythereinae Mandelstam. J. Paleont. 44
KEYSER, D. 1983. Ultrastructure of carapace-sensilla in Aurilu convexa (Baird, 1850) (Ostracoda, Crustacea). In MAD
DOCKS, R.F. (ed.). Applications of Ostracoda,649-658. Department of Geosciences, University of Houston, Hou-
-1982. Development of the sieve pores in Hirschmunnia viridis (0.F. Miiller, 1785). I n BATE, R.H., ROBINSON, E.
(eds.). Ostracods, 51-60. Ellis Horwood Ltd. Publishers, Chichester.
242 Y.T. How AND Y.H. ZHAO
w. 1973. zur Ultrastruktur, Mikromorphologie und Taphonomie des Ostracoda-Carapax. Palaeontographica Abt. A, 144 (1-3). 1-111.
OKADA, Y. 1982a.Structureand cuticleformation of the reticulated carapaceof the ostracodeBicornucythere bisanensis.
Lethaia, 15 (1). 85-100.
-1982b. Ultrastructure and pattern of the carapace of Bicornucythere bisanensis (Ostracoda, Crustacea). In
HANAI, T. (ed.). Studies of Japanese Ostracoda. Univ. Mus., Univ. Tokyo, Bull., 20, 229-255.
-1983.Ultrastructure and functions of pores of ostracodes. In MADDOCKS, R.E. (ed.). Applications of Ostracoda,
640-648. Department of Geosciences, University of Houston, Texas.
PURI, H.S. 1974. Normal pores and the phylogeny of Ostracoda. In BOLD, W.A. VAN DEN, (ed.). Ostracoda, the H.V.
Howe Memorial Volume. Geoscience and Man, 6, 137-151.
- and DICKAU, B.E. 1969.Use of normal pores in taxonomy of Ostracoda. Trans. Curf Coast Assoc. Geof.Sac.,
ROSENFELD, A. and VESPER, B. 1976.The variability of the sieve-pores in recent and fossil species of Cyprideis torosa
(Jones, 1850)as an indicator for salinity and palaeosalinity. In L~FFLER,H. and DANIELOWL, D. (eds.). Aspects of
Ecology and Zoogeography of Recent and Fossil Ostracoda, 55-67. Junk, The Hague.
Ultrastructure of Myodocopid Shells
I.G. SOHNAND LOUISS. KORNICKER
U.S. Geological Survey, Washington,D.C. and
National Museum of Natural History, Washington, D.C.,U.S.A.
Based on the study of scanning electron micrographs of cross-sections of ostracod shells representing 17 species in genera of the suborders Cladocopina, Halocypridina, and Myodocopina, five
primary components are identified in the endocuticle: 1-laminate, 2-columnar, 3-fine granular,
4-coarse granular, 5 -homogeneous. Crystalline nodules, rare in vivo, but common in preserved
specimens, are considered to represent a secondary component. Preliminary experimentation with
sun-dried shells of Vargula hilgendorfi indicates that crystalline nodules form in 10% buffered formalin, a commonly used preservative of plankton. Examination of two growth stages of this
species suggests the same general combination of components during ontogeny.
Pelagic species of Gigantocypris, Halocypris, Conchoecia, and Macrocypridina have laminate
endocuticles, but the pelagic Codonocera polygonia has both laminate and coarse granular components in the endocuticle. Benthonic species may have only one or a combination of any of the
five components, but not more than four components in a species.
Based on this and previous studies, the ultrastructures of the endocuticles of the following taxa
are known: Metapolycope hartmanni, Polycope sp., Conchoecia atlantica, C. valdiviae, C . belgica,
Halocypris injlata, Thaumatoconcha caraionae, T. tuberculata, Asteropterygion setiferum, Macrocypridina castanea, Gigantocypris muelleri, Scleroconchafolinii, Vargulahilgendorfii, Codonocerapolygonia, Eusarsiella texana, E. disparalis, Spinacopia sp.
The purpose of this study is to examine cross-sections of the shells of myodocopid ostracods
with scanning electron microscopy (SEM) in order to determine their ultrastructure. We report
on the ultrastructure of 17 species in the suborders Cladocopina, Halocypridina, and Myodocopina, and we identify five different primary components in the shells (Table 1); crystalline nodules
are considered to be a secondary component. The combinations of the various components of the
shells are discussed relative to taxonomy and environment.
Scanning electron microscopy techniques in the National Museum of Natural History were re243
244 I.G. SOHN AND L.S. KORNICKER
Metapolycope hartmanni Kornicker and
van Morkhoven, 1976
Conchoecia atlantica (Lubbock, 1856)
C. belgica Muller, 1906b
C . valdiviae Muller, 1906a
Halocypris inflata (Dana, 1849)
Thaumatoconcha caraionae (Kornicker
and Sohn, 1976)
T. tuberculata Kornicker and Sohn, 1976
Asteropterygion setiferum Kornicker and
Codonocera polygonia Poulsen, 1962
Eusarsiella disparalis (Darby, 1965)
E. texana (Kornicker and Wise, 1962)
Gigantocypris muelleri Skogsberg, 1920
Macrocypridina castanea (Brady, 1897)
Scleroconcha folinii (Brady, 1871)
Vargula hilgendorfii (Muller, 1890)
Kornicker and van Morkhoven, 1976
Herein, P1. 2, fig. 4.
Herein, P1. 1, figs. 6-9; P1. 2,fig. 5.
Bate and East, 1972,fig. 10; 1975,PI. 3,
Bate and Sheppard, 1982,P1. 7, figs. 1,2.
Bate and Sheppard, 1982,P1. 4, fig. 4;
Herein, PI. 4, fig. 7.
Herein, PI. 4,figs. 8-10.
Herein, PI. 1, figs. 1 0 , l l ; Kornicker,
1975,figs. 17, 18.
Bate and Sheppard, 1982,PI. 2, fig. 5.
Herein, PI. 4,figs. 3-6; PI. 5, figs. 14,15.
Herein, P1. 5, figs. 7-9.
Herein, PI. 1, figs. 1-5; Harding, 1965,
Herein, PI. 2,fig. 1 ; Bate and East, 1975,
P1. 3, figs. 9, 10.
Herein, PI. 2, figs. 2, 3.
Herein, P1. 5, figs. 10-13.
Herein, PI. 2,figs. 6-8; P1. 3,figs. 1-7;
P1. 4., figs.
(X = present, - = absent, B = benthonic, P = pelagic)
cently described (Sohn, 1983, p. 10). Except for those specimens of VurguZa hiZgendorfi (Muller,
1890) that were sun-dried as soon as collected, the specimens prepared for scanning electron microscopy had been preserved in alcohol. The sun-dried specimens were fractured by pressing with
a thick needle, and the fragments were mounted on stubs for study. The wet specimens were either
PLATE1-Figs. 1-5. Gigantocypris muelleri Skogsberg, 1920.USNM 151241A. 1,2,section made by cryofracture
to show laminae, approx. x 1,450and x 5,800,respectively. Area of 2 shown by arrow on fig. 1. Figs. 3-5,
torn sections of the same specimen, approx. x 470, x 1,500,and x 4,700,respectively. Arrow on fig. 3 indicates
epicuticle; area of 5 shown on fig. 4 by arrow; outer surface of valve towards bottom of plate. Locality 1.
Figs. 6-9. Conchoecin atlantica (Lubbock, 1856). Adult male, left valve, USNM 149290.6,7,cut sectionsnear
dorsal margin above incisur of valve showing laminae, approx. x 2,000 and x 4,500, respectively. Adhering
objects are bacterial contamination during preparation. Sections oriented with outer surface of valve towards
top of plate. 8,9,cut section in other area behind midlength at midheight of same fragment, approx. X 2,200
respectively. Area of 9 shown by arrow on fig. 8; laminae separated during preparation. Sections
oriented with outer surface of valve towards top of plate. Locality 2. Figs. 10, 11. Asteropterygion setiferum
(Kornicker and Caraion, 1974). Adult female, right valve sliced with razor blade, USNM 143996.10,epicuticle
(arrow) and part of laminated endocuticle, showing that elongate process is confined to epicuticle, approx.
X 5,100.11, detail showing laminae, approx. x 9,800.Sections oriented with outer surface of valve towards
top of plate. Locality 3.