Neocrassinid bivalves heterodonta from the middle bathonian ...

Paliiont. Z.

66

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67-79

25 Abb.

Stuttgart, Juni 1992

Neocrassinid bivalves (Heterodonta) from the Middle Bathonian (Jurassic) of Kachchh, Western India ASASD K. JMTLY, Varanasi* With 25 figures Kurzfassung: Sechs Taxa der Muschelgattung Neocrassina werden aus Sedimenten des Mittelbathon (Jura) yon Kachchh, westliches Indien, beschrieben. Die Arten Neocrassina (N.) ovata (SMITH),N. (N.) robusta (ETALLON)und N. (N.) paphia (D'ORBIGNY)sind bereits aus Europa bekannt, w~ihrend N. (N.) pandeyi MAITHANI,N. (N.) sp. A. und N. (N.) sp. B endemisch sind. Dariiber hinaus werden die Gattungs- und Untergattungsmerkmale von Neocrassina und die verwandtschaftlichen Beziehungen der verschiedenen Taxa diskutiert. Abstract: Six bivalve taxa belonging to the genus Neocrassina FISCHERhave been described from Middle Bathonian (Middle Jurassic) rocks of Kachchh, Western India. Of these, Neocrassina (N.) ovata (SMITH),N. (N.) robusta (ETALLON)and N. (N.)paphia (D'OR13IGNY)have been recorded previously from various parts of Europe, while Neocrassina (N.) pandeyi MAITVIANIis an endemic faunal element as are Neocrassina (N.) sp. A and Neocrassina (N.) sp. B. The generic and sub-generic characters of Neocrassina are reviewed as are affinities of the taxa with closely related forms from India and other parts of the world.

Introduction

The Jurassic bivalve fauna of Kachchh, W. India, biogeographically belongs to the Ethiopian faunal province which compared with their European counterparts is far less known. The majority of bivalves from Kachchh so far described are endemic. However, only part of them are truly endemic, the other "new species" being due to lack of comparison with European taxa. Thus, there is clearly a need for revising most of the recorded taxa from Kachchh, which may in turn help to better understand the relationship between the Ethiopean and European faunal provinces. Some of the European taxa recorded by SINGH ~ JMTLY (1983), JAITLY (1986 a, b, 1988, 1989) from Bajocian-Bathonian horizons of North Pachchham Island (Kachchh) are listed here:

Bakevellia (B.) waltoni (LYCETr),Meleagrinella echinata (SMITH), Camptonectes (C.) laminatus (J. Sow.), Camptonectes (C.) auritus (ScHLOTHEIM),Camptonectes (C.) rigidus (J. Sow.), Camptonectes (Indonectes1) obscurus (J. Sow.), Ctenostreon proboscideum (J. Sow.), Plagiostoma amnifera (WHIDBORNE),Plagiostoma schimperi (BRANCO),Pseudolimea duplicata (J. DE C. Sow.), Sowerbya woodwardi LYCETT,Isocyprina (I.) simplex ARKELL,Ceratomyopsis striata (D'OP~IGNY),Eocallista (E.) tancrediformis (BLAKE& HUDLESTOtq),and Pleuromya alduini (BRoNGNIART). 1 A new subgenus created by KANJILAL(1978), while JOHNSON(1984) prefers the subgenus Camptochlamys for it. * Address of the author: A. K. JAITLY,Department of Geology, Banaras Hindu University, Varanasi 221 005, India. 0031-0220/92/0066-0067 $ 3.25 9 1992E. Schweizerbart'scheVerlagsbuchhandlung,D-7000Stuttgart1

68

Anand K. Jaitly

Apart from these taxa, there are many others which have shown close morphological semblance to European taxa, but their imperfect state of preservation warranted their identification with some reservation. The astartids constitute a group of heterodont bivalves which occur abundantly in the Jurassic of Kachchh. They are represented by Astarte s.s., Neocrassina s.s., Neocrassina (Coelastarte), Neocrassina (Provoustiella), Nicaniella s.s., Nicaniella (Trautscholdia), and Prorokia s.s. These taxa have been recorded by SOXVERBY(1840), SPATI-t(1933), Cox (1940), AGRAXVAL(1956), MAtTHANI(1968), and SINGH~ KANJILAL(1982). The six taxa described here belong to Neocrassina s.s. and were collected from the Middle Bathonian of North Pachchham Island (for location and geology, see JAITLY 1985). The occurrence of Middle Bathonian strata in Kachchh has been discussed by JAITLY SINGH (1984). Still older Middle Jurassic (Upper Bajocian) rocks and fossils were recorded and described by JAITLY~ SINGH(1983 a, b). Therefore, in the Jurassic of Kachchh, which is famous world over for its Callovian molluscs, special attention should be paid also to the Bajocian-Bathonian strata. Repository: All specimens are housed in the Invertebrate PalaeontologyLaboratory, Department of Geology,Banaras Hindu University,Varanasi 221 005, India.

Systematic p a l a e o n t o l o g y Subclass H e t e r o d o n t a NEUMAYR 1884 Superfamily Crassatellacea FERRUSSAC 1882 Family Astartidae D'ORBIGNY 1884 Subfamily Astartinae D'ORBIGNY 1844 Genus Neocrassina FISCHER 1886 Type species: Astarte obliqua DESHAYES1830; SD DALL 1903 (Cypricardia obliqua LAMARCK 1819), from the Bajocianof France. Subgenus Neocrassina s.s. Diagnosis: Outline ovate to subtrapezoidal, inequilateral; umbones small to slightly produced, pointed; lunule well depressed, escutcheon narrow and elongated; concentric ribs more pronounced in umbonal region, fading towards the ventral margin. Hinge with two trigonal cardinals and strong posterior laterals; nymph broad and flattened; interior margin crenulated to smooth. AI 3a 3b PI Hinge formula: AII 2 4b PII Remarks: There is much confusion as to the status of the subgenus Provoustiella created by AGRAWAL(1956) tO accommodate astartids having flat and depressed umbo, high tumidity in the dorsal region, and very coarse angular concentric ribs in dorsal region only. CHAVAN(1945, 1969) regarded it as a subjective synonym of Neocrassina. This was followed by ZAKI-IAROV(1970) and DUFF (1978), who kept it as synonym of Neocrassina s.s. Voids (1980), while revising the classification adapted by NEXVELL(1969) for the Treatise listed Provoustiella as subgenus of Neocrassina. Contrary to these workers, MAITI~ANI(1968) and SINGt~ ~ KANJILAL(1982), describing in detail some Jurassic astartids of Kachchh, retained Provoustiella as subgenus of Neocrassina. Most of the specimens in the author's collection show some resemblance in surface sculpture to the subgenotype Astarte (Provoustiella) freneixae AGRAWAL (1956: pl. 21, figs. 5--6) in having coarse concentric ribs

Neocrassinid bivalves (Heterodonta) from the Middle Bathonian (Jurassic)

69

in the dorsal region and fading ventrally. However, this character is also found in many other neocrassinids described by various authors. The other two diagnostic features of Provoustiella, the tumidity in the dorsal region and flatness of the umbo depends upon the shell inflation and, on careful observation, may be found to be transitional. None of the specimens so far described under the above subgenus exhibits hinge characters. Conclusively, externally there is no significant difference between Provoustiella and Neocrassina s.s. and a separate subgeneric status can be given to the former only when it is found to possess a different hinge character.

A

A A

60

1 A

it A

9 A

9

A

A

9

9 9

A A

6

35 A

i

I

I

I

I 35

9

A

9

9

I

I

in

9

I

I ~0

I

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I L

mm

Fig. 1. Length/height ratio of Neocrassina (Neocrassina) ovata (dots) and Neocrassina (Neocrassina) rovusta (triangles).

Neocrassina (Neocrassina)

ovata

(SMITH)

Figs. 1, 2 - 9 1817 Astarte ovata n. sp. - W. SMITH: 44, 51, 105 (Reference fig. in 1816, Oak Tree Clay Plate, fig. 8). 1834 Astarte ovata SMITH - J . DE C. Sow.: pl. 645, figs. 1-3. 1871 Astarte ovata SMITH -- PmLLIVS: pl. 13, fig. 26. 1877 Astarte subdepressa n. sp. - BLAKE a, HUDLESTON: 393, pl. 14, fig. 10. 1932 Astarte michaudiana D'ORBIGNX -- COXTREAU: 192, pl. 65, figs. 19, 20. 1934 Astarte ovata SMtTH- AR~ELL: 231, pl. 32, figs. 1--12, text-figs. 55, 56. 1934 Astarte subdepressa BLAKE ~ HUDLESTON-- ARI~LL: 235, pl. 33, figs. 1--9. 1955 Astarte (Neocrassina) rajnathi n. sp. - AGRAXVAL:433, pl. 21, figs. 1--4. 1968 Astarte (Neocrassina) cornpressaJ. DE C. Sow. - MArrHANI: 511, pl. 32, figs. 1--2 (non J. DE C. Sow.).

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Anand K. Jaitly

1968 Astarte (Neocrassina) rajnathi AGV,AWAL-- MAITHANI:511, pl. 32, figs. 3--4. 1968 Astarte (Provoustiella) unilateralisJ. DE C. Sow. - MAITHANI:513, pl. 32, fig. 6 (non J. DE C. Sow.). 1968 Astarte (Provoustiella) rnurthyi n. sp. - MAITHANr:515 (pars). 1982 Neocrassina (Neocrassina) rajnathi AGVatXVAL-- SINGI-iKANIILAL:50, pl. 1, figs. 4--5. Material: Twenty specimens (PK/120/25, 27, 56, 83, 92, 96, PK/121/77, PK/122/8, 18, 54, Pk/123/ 12, 14, 15, 16, 26, 40, 56, 73, PK/126/4, 25). H o r i z o n a n d 1o c alit y : Middle Bathonian of Kala Dongar, North Pachchham Island, Kachchh. A m e n d e d d e s c r i p t i o n : The specimens are ovate, trigonally ovate to subquadrate in outline, strongly inequilateral, moderately to strongly inflated. Umbones small, acute, prosogyrous and situated between anterior third to anterior quarter of shell-length. Posterodorsal margin gently curved, anterior margin concave below umbo, almost straight to gently curved. Ventral margin symmetrically and moderately convex. All margins meeting each other in smooth curves. Lunule small, ovate and feebly to moderately impressed. Escutcheon long, narrow and of variable depth. Interior ventral margin crenulated. Shell surface consists of commarginal ribs which are closely spaced in the dorsal region and widely and irregularly distributed on the rest of the surface. In some specimens thickness of ribs increases and sharpness decreases from anterior to posterior margin. Dimensions (in ram): Specimen No. PK/120/96 PK/123/73 PK/126/25 PK/122/77 PK/122/18 PK/122/14 PK/120/25 PK/122/56

PK/122/88 PK/120/92 PK/123/16 PK/123/40 PK/123/56 PK/122/83 PK/123/12 PK/120/56 PK/123/26 PK/123/15 PK/120/77 PK/126/4

Length

Height

Inflation

42.5 41.5 41.0 41.0 40.5 40.5 40.0 39.0 39.0 38.0 37.0 37.0 36.0 36.0 36.0 34.5 34.5 34.0 34.0 33.0

38.0 35.5 37.5 36.0 36.0 35.0 33.0 38.0 34.0 30.0 32.5 31.0 35.0 34.0 32.0 32.5 30.5 32.0 30.5 28.0

19.0 20.5 19.5 20.0 19.0 20.5 18.0 17.0 18.5 18.5 17.5 17.5 15.5 17.5 17.5 18.5 18.0 20.0

R e m a r k s : Neocrassina (Neocrassina) ovata (SMrTH) is a highly variable species exhibiting wide ranges of variation in shell tumidity and shape. The surface ornamentation is also much variable; ARKELL (1934) stated that the concentric ribs are prominent in the dorsal region only and fading ventrally or even becoming smooth. However, the figure of the type specimen reproduced by him shows concentric ribs prominent at the dorsal region and irregularly distributed and of variable strength over the rest of the surface. Some of the

Figs. 2-9. Neocrassina (Neocrassina) o v a t a (SMITH),2: Left valve exterior (PK/120/77); 2a: dorsal view; 3: right valve exterior (PK/123/15); 4: right valve exterior (PK/120/25); 5: right valve exterior (PK/123/12); 6: right valve exterior (PK/12/19); 7: right valve exterior (PK/126/4); 8: right valve exterior (PK/122/77); 8a: dorsal view; 9: left valve exterior (PK/122/77).


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specimens described by ARKELL do show similar surface characters. Another taxon, N. (N.) subdepressa (BLAKE ~ HVDLESTON), has been separated from ovata as the former is smaller in size and the concentric ribs are of equal prominence throughout the shell surface. The type specimen and the specimens described by ARKELL (1934) exhibit prominent concentric ribs in the dorsal half which become irregular in thickness as well as in distribution ventrally. Therefore, in the early stages of growth both ovata and subdepressa are indistinguishable due to having similar outline and surface ornamentation. Another taxon, N. (N.) rajnathi (AG~wAL), created by AGRAWAL (1956) from the Callovian-Oxfordian of Kachchh displays surface characters intermediate between ovata and subdepressa, while the remaining characters are more or less similar in all three taxa. The L / H ratio (Fig. 1) of these other specimens is also gradual and falls well within the range of ovata. Therefore, the author regards ovata, rajnathi and subdepressa as conspecific. Since ovata has priority of date over the other two, the name ovata has been retained. There can be one objection to the merging of the these three taxa; their record from different stratigraphic horizons. The type of ovata comes from the Corallian (Middle to Upper Oxfordian) as does the type of subdepressa; N. rajnathi comes from CallovianOxfordian. The specimens collected by the author are all from the Middle Bathonian, but they are so similar to the three taxa exhibiting all gradations and variations of morphological characters, that they cannot be separated from ovata solely on the basis of occurring at different stratigraphic horizons. In the Jurassic, many bivalves are found to be long ranging and the present case is no exception. HALLAM (1976) has also given the range of subdepressa in Europe as Callovian to Oxfordian. It can be therefore safely concluded that Neocrassina (Neocrassina) ovata (SMITH) ranges from the Middle Bathonian (Middle Jurassic) to Oxfordian (Upper Jurassic). The three taxa, Astarte (Neocrassina) compressa J. DE C. Sow., A. (Provoustiella) unilateralisJ. DE C. Sow. and A (P.) murthyi, described by MAITI~Am (1968) from the Habo Dome of Kachchh, have been included in the synonymy of ovata, since they are unseparable from it in light of the amended morphological characters.

Neocrassina (Neocrassina) robusta Figs. 1, 12-21, 25

(ETALLON)

1862 Astarte robusta n. sp. - ETALLONin ETALLON& THURMANN:193, pl. 24, fig. 1. 1888 Astarte robusta ETALLON LORIOL:277, pl. 32, figs. 6--7. 1891 Astarte robusta ETALLON LORIOL:230, pl. 24, figs. 13--15. Material: 20 specimens (18 articulated, 1 right and 1 left valve): PK/120/49, 52, 73, PK/121/59, PK/ 122/18, 50, 63, 81, 84, 87, 93, PK/123/5, 11, 20, 27, 38, PK/126/4, 22, 27, PK/143/34. Horizon and locality: Middle Bathonian of Kala Dongar, North Pachchham Island, Kachchh. -

-

Figs. 10-11. Neocrassina (Neocrassina)paphia (D'ORRmt~Y).10: Right valve exterior (PK/123/37); 11: left valve exterior (PK/126/15). All figures in natural size. Figs. 12-21. Neocrassina (Neocrassina) robusta (ETALLON). 12: Right valve exterior (PK/122/87); 12a: dorsal view; 13: right valve exterior (PK/123/38); 14: left valve exterior (PK/122/81); 15: left valve exterior (PK/123/51); 16: left valve exterior (PK/120/52); 17: right valve exterior (PK/126/22); 18: right valve exterior (PK/120/73); 19: left valve exterior (PK/123/11); 20: left valve exterior (PK/123/20); 21: left valve exterior (x 0.7) (PK/122/63). All figures in natural size except Fig. 21.


73

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Anand K. Jaitly

D e s c r i p t i o n : The specimens are orbicular to suborbicular in outline, slightly inequilateral to almost equilateral and moderately to strongly inflated. Umbones small, prosogyrous, depressed to acute with their position variable from slightly anterior to the middle to almost central. The posterodorsal margin is gently to moderately convex, posterior asymmetrically arched and all the margins together describe a circle but for the slight concavity anteriorly below the umbo. Lunule varies both in shape and depth from circular to heartshaped and from shallow to deep. Escutcheon long, narrow and of variable depth. Inner shell-margin crenulated. Surface with concentric ribs of irregular thickness and separated by narrower interspaces. The concentric ribs become gradually faint ventrally. Dimensions (in mm): Specimen No.

Length

Height

Inflation

PK/120/49 PK/120/52 PK/12/63 PK/122/50 PK/143/34 PK/126/27 PK/122/59 PK/120/73 PK/123/38 PK/123/27 PK/122/87 PK/126/22 PK/122/84 PK/122/18 PK/123/5 PK/122/81 PK/123/ll PK/123/20 PK/125/4 PK/120/93

43.0 42.5 41.5 41.5 41.0 40.5 40.0 39.5 39.0 39.0 39.0 39.0 38.5 38.5 37.5 37.0 37.0 36.0 35.0 -

41.0 41.0 41.0 37.0 40.0 39.5 39.0 38.5 40.0 38.0 37.0 36.0 38.0 35.5 37.5 37.0 35.0 35.0 34.0 29.5

18.5 13.0 (left valve) 22.0 21.5 21.5 20.5 22.0 22.0 14.0 (right valve) 21.0 22.5 22.0 22.0 22.5 22.5 18.0 18.0 16.0 14.0

R e m a r k s : The specimens agree satisfactorily with the Corallian species in all essential characters and hence, in spite of its occurrence at a much lower stratigraphic horizon, these have been assigned to Neocrassina (Neocrassina) robusta (ETALLON). Astarte rotunda LXCETT(MORRIS & LYCETT1853: 80, pl. 9, fig. 12) from the Great Oolite of Britain and Astarte (Astarte) tiberaddeni SKWARKO(1974: 96, pl. 34, figs. 14, 17--19) from the Bajocian of Western Australia, are very close in outlines but differ in ornamentation.

Neocrassina (Neocrassina) paphia

(D'ORBIGNY)

Figs. 10, 11 1927 Astartepaphia D'ORBIGNY-- COTTREAU:48, pl. 47, figs. 25--26. M a t e r i a I : Two partially broken articulated specimens. Horizon and locality: Middle Bathonian, Kala Dongar, Pachchham Island, Kachchh. D e s c r i p t i o n : The specimens are of medium size for the genus, trigonally ovate in outline and moderately inequilateral. The umbones are obtuse, prosogyrous and situated at about one-fourth of the shell length from the anterior. Posterodorsal margin long, straight and moderately inclined (at about 30 ~ meeting the gently convex posterior margin at a rounded-off obtuse angle. Antero-dorsal margin gently concave, anterior margin short and

Neocrassinid bivalves(Heterodonta)from the Middle Bathonian (Jurassic)

75

acutely rounded. The ventral margin is asymmetrically convex and merges with the anterior and posterior ones smoothly. Lunule small, deep and elliptical; escutcheon long, shallow, and lanceolate. Ventral margin crenulated internally. Surface with fine concentric ribs separated by narrower interspaces. The ribs are prominent throughout the surface. At a shell height of about 30 mm there are about 37 of them. Dimensions (in ram): Specimen No. Length

Height

Inflation

PK/126/15 PK/123/27

26.0 28.5

12.5

at 30.0 at 31.0

Remarks: The specimens corresponds closely to Astarte paphia D'ORB~GNVin general outline, nature and position of umbo and surface ornamentation. The number of ribs in the specimen from France also appears to be the same as in the present specimens.

Neocrassina (Neocrassina) pandeyi MAITHANI Fig. 22 1968 Astarte (Neocrassina)pandeyin. sp. -MaITHaNI: 512,pl. 32, fig. 8. 1982 Neocrassina(Neocrassina)pandeyiMA~T~ANI-- SINGH~ KANJILA/.:52, pl. 1, figs. 6--8. Material: 1 articulatedspecimen. Horizon and locality: Middle Bathonian, Kala Dongar, North Pachchham Island, Kachchh. Dimensions (in mm): SpecimenNo. Length Height Inflation PK/126/18

52.0

48.5

25.5

Remarks: The characters of the species, originally founded on a poorly preserved holotype (G.S.I. type No. 16947), were later on modified by SINC~ ~ KANJILAL(1982) tO show the wide ranges of variation in outline, dimensions and position of umbo. The present specimen complies fully in all characters with the species. It was known earlier from the Lower to Middle Callovian of Habo Dome, Kachchh. The present record lowers its range to Middle Bathonian.

Neocrassina (Neocrassina) sp. A Figs. 23, 23a Material: 1 articulatedspecimen. Horizon and locality: Middle Bathonian, Kala Dongar, North Pachchham Island, Kachchh. D e s c r i p t i o n : Shell moderately inequilateral, strongly inflated, tall, subelliptical, widening gradually towards ventral margin. Maximum shell inflation along a broadly rounded diagonal ridge extending from the umbo towards the posteroventral end. Posterodorsal margin long, gently convex and marging gradually with a little more convex but small posterior. Anterodorsal margin small and concave, meeting the long and moderately convex anterior margin in a wide curve. Ventral margin almost straight, meeting the anterior and posterior margins at rounded off obtuse angles. Umbo acutely pointed, prosogyrous and placed at about one-third of shell length from the anterior. Lunule ovate, deep and large; escutcheon long, elliptical and shallow.

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Fig. 22. Left valve exterior of Neocrassina (Neocrassina)pandeyi MAITHAm(PK/126/18). Figs. 23, 23a. Right valve exterior (23) and dorsal view (23a) of Neocrassina (Neocrassina) sp. A (PK/120/

st).

Figs. 24, 24a. Right valve exterior (24) and dorsal view (24a) of Neocrassina (Neocrassina) sp. B (PK/120/

57).

Fig. 25. Left valve exterior of Neocrassina (Neocrassina) robusta (ETALLON)(PK/120/93).

Surface with fine, regularly spaced concentric ribs. They are sharp in the umbonal region, but become gradually flattened ventrally. Ventral margin crenulated internally. Dimensions (in mm): Specimen No. Length

Height

Inflation

PK/126/81

34.2

21.0

31.0

R e m a r k s : The specimen is unique in its tall and subelliptical outline and gradual widening towards the ventral margin. The author is unaware of any comparable form. In all probability it appears to be a new taxon. However, for want of more material, it has been described here without any qualification.


77

Neocrassina (Neocrassina) sp. B Figs. 24, 24a Material: 1 articulated specimen. H o r i z o n a n d 1o c alit y : Middle Bathonian, Kala Dongar, North Pachchham Island, Kachchh. D e s c rip t i o n: Shell of medium size, strongly inequilateral, subtrapezoidal and gradually widening posteroventrally. Inflation rather feeble, maximum being in the umbonal region along an oblique ridge extending from the umbo towards posteroventral end of the shell; inflation decreasing rapidly towards all margins except the posterodorsal one in such of a way that the marginal region is flattened. Umbo acute, pointed, prosogyrous, projecting slightly above the hinge margin and placed at about one-tenth of the shell length from the anterior. Posterodorsal margin roughly straight, sloping gently and meeting the strongly convex posterior margin at a very wide angle. Anterodorsal margin strongly concave in front of the umbones: anterior end short, describing a regular curve with the posterior end. Lunule deep, wide, elliptical and bordered by sharp umbonal ridges; escutcheon absent. Shell surface ornamented with regular, fine concentric ribs in the dorsal half; ventral half bears only irregular rugae and growth-halts. Dimensions (in mm): Specimen No. Length

Height

Inflation

PK/120/59

37.5

16.0

41.0

R e m a r k s : The present specimen is very close to the group of Astarte hermanni OPPEL

(HOLDHAUS1913: 440, pl. 99, figs. 7-11), Astarte scytalis HOLDHAUS (1913: pl. 100, figs. 2, 3) and Astarte sowerbyana HOLDHAUS(1913: 443, pl. 99, figs. 12, 13, 15, pl. 100, fig. 1). But all these taxa from Spiti Shales of North India possess a prominent escutcheon and a narrow shell towards the posteroventral end. No other closely comparable species was found in the available literature.

Acknowledgements The author expresses his deep sense of gratitude to Prof. Dr. F. T. Ff)RSICHof University of Wiirzburg, F.R.G., for critically reviewing the manuscript and rendering many useful suggestions. He is also thankful to Dr. S. KANJILALOf Banaras Hindu University, India, for fruitful discussions.

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AOV,-~WAL,S. K. 1956. Sur un nouveau sous-genre et deux esp~ces nouvelles d'Astarte du Jurassique de Kutch (Inde). - Bulletin de la Societe g6ologique de France, ser. 6, 5: 433-439, Paris (for 1955). ARIIELL, W. J. 1934. A monograph of British Corallian Lamellibranchia, Part. vi. - Palaeontographical Society Monographs 86: 229-276, London. BLAKE,J. D. ~, HUDLESTON,W. H. 1877. The Corallian Rocks of England. - Quarterly Journal of the Geological Society of London 13: 260-405, London. CHAVAN,A. 1945. Les lamellibranches h6t6rodontes des sables astartiens Cordbugle (Calvades).- Journal de Conchyliologie 86: 41-86, Paris. CHAVAN, A. 1969. Systematic descriptions: Family Astartidae. - [In:] MOORE, R. C. (ed.) Treatise on Invertebrate Palaeontology, Pt. N, Bivalvia 2: N562-N573, Geological Society America, New York and University of Kansas Press, Lawrence, Kansas. COVTREAU,J. 1927. Type du Prodrome de Pal6ontologie stratigraphique universelle d'Alcide D'ORBIGNY. 2, Callovien-Portlandien. -Annales de Pal6ontologie 16: 101-132, Paris. - 1932. Type du Prodrome de Paldontologie stratigraphique universelle d'Alcide D'ORBIGNV, 2, Callovien-Portlandien. - Annales de Pal6ontologie 21: 1-30, Paris. Cox, L. R. 1930. On British fossils named by WILLIAMSMITH. Annals and Magazine of Natural History, ser. 10, 6: 287-304, London. - 1936.Fossil Mollusca from southern Persia (Iran) and Bahrain Island. - Palaeontologica India, New Series 22, Memoir 2: 1-69, Calcutta. - 1940.The Jurassic lamellibranch fauna of Kachh (Cutch). - Palaeontologica Indica, Series 9, 3 (3): 1-157, Calcutta. DUFF, K. L. 1978. Bivalvia from the English Lower Oxford Clay (Middle Jurassic). - Palaeontographical Society Monograph: 1-137, London. GREPPIN,J. B. 1870. Description g~ologique du Jura Bernois et de quelques districts adjacent. - Mat~riaux pour la Carte g~ologique de la Suisse 8: 1-357, Geneva. HALLAM, A. 1976. Stratigraphic distribution and ecology of European Jurassic bivalves. - Lethaia 245-259, Oslo. HOLDHAUS,K. 1913. Fauna of the Spiti Shales (Lamellibranchiaand Gastropoda). - Palaeontologica Indica, Series 15, 4 (2): 397-456, Calcutta. JAITLY,A. K. 1985. A note on the stratigraphy of the Middle Jurassic rocks of Kala Doongar, Pachchham Island, dist. Kachchh, Gujarat. - Current trends in Geology 7: 55-62, New Delhi. - 1986a.Indomya, a new subgenus of Pholadornya from Middle Jurassic of Kachchh, Western India (Bivalvia: Pholadomyidae). - The Veliger 28 (4): 457-459, Berkeley, Ca. 1986b. Middle Jurassic limids from Kala Doongar, Pachchham Island, Kachchh, Gujarat. Quarterly Journal of the Geological, Mining and Metallurgical Society of India 57 (1): 42-52, Calcutta. 1988. Some Middle Jurassic clams from Kala Doongar, Pachchham Island, Kachchh, Gujarat. Indian Minerals 42 (2): 117-125, Calcutta. 1989.Some rare veneroid clams from Middle Jurassic rocks of Kala Doongar, Pachchham Island, District Kachchh (Gujarat). - Proceedings of the Indian National Science Academy, A 55 (3): 570-577, New Delhi. JAITLY, A. K. & SINGri, C. S. P. 1983a. Stratigraphy of the Bajocian sediments of Kachchh, Gujarat (W. India). - Proceedings of the Indian National Science Academy, A 49 (4): 503-508, New Delhi. - 1983b.Discovery of late Bajocian Leptospbinctes BtSCKMAN(Jurassic Ammonitina) from Kachchh, Western India. - Neues Jahrbuch fiir Geologie und Pal~iontologie, Monatshefte 1983 (2): 91-96, Stuttgart. 1984.On the Bathonian (Middle Jurassic) ammonites Micromphalites BUCKMANNand Gracilisphinctes BUCk:MANfrom Kachchh, Western India. - Geological Magazine 121 (4): 319-321, London. JOHNSON, A. L. A. 1984. The palaeobiology of the family Pectinidae and Propeamussiidae in the Jurassic of Europe. - Zitteliana 11: 3-235, Munich. KANJILAL,S. 1978. Jurassic Carnptonectes (Bivalvia) from Habo Hill, District Kutch (Gujarat), W. India. Journal of Molluscan Studies 45: 115-124, London. LORIOL, P. DE 1888. Etudes sur les mollusques des couches corallig~nes infdrieures du Jura Bernois. M6moires de la Soci6t6 Pal6ontologique Suisse 15: 277, Geneva. 1891.Etudes sur les mollusques des couches corallig~nes infdrieures du Jura Bernois. - Mdmoires de la Soci6t6 Pal6ontologique Suisse 18: 230-232, Geneva. MAITHANr,J. B. P. 1968. Some new species of the Jurassic gastropods and lamellibranchs from Habo Dome and their usefulness in correlation - Records of the Geological Survey of India 95 (2): 491-524, Calcutta. - -

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MORRIS, J. e, LYcr'rr, J. 1853. A monograph of the Mollusca from the Great Oolite. Part 2 (Bivalves) Palaeontographical Society Monographs: 1-80, London. NEWELL, N. D. 1969. Superfamily Crassatellacea. - [In:] MOORE, R.C. (ed.) Treatise on Invertebrate Palaeontology, Pt. N, Mollusca 6, Bivalvia 2: N1-N592, Geological Society America, New York and University of Kansas Press, Lawrence, Ka. PHILLIVS,J. 1871. Geology of the Oxford and the valley of Thames. - 523 pp., Oxford. SINOH, C. S. P. ~ JAITLY,A. K. 1983. Studies on the Jurassic pectinid clams from the Kala Doongar Hill, Pachchham Island, Kachchh. - Journal of the Palaeontological Society of India 28: 43-49, Lucknow. SIr~GH, C. S. P. ~ KArqJILAL,S. 1982. On some Jurassic astartid bivalves from the Habo Hill in Kutch. Journal of the Palaeontological Society of India 27: 49-61, Lucknow. SMITH, W. 1817. Stratigraphical system of organised fossils with reference to the specimens of the original geological collection in the British Museum. - 113 pp., London. SOXVERBY,J. DE, C. 1823-1825. The Mineral Conchology of Great Britain.- Volume 5:1-171, pls. 408-503, London. - 1840. Description of fossils from the Upper Secondary Formation of Cutch collected by C. W. Grant. - Transactions of the Geological Society of London, Serie 2, 5: Explanation of Plate 21, figs. 8-17, London. SPATrt, L. F. 1933. Revision of Jurassic cephalopods from Kachh (Cutch). - Palaeontologica Indica, New Series 9, 2 (6): 639-945, Calcutta. SXeARKO,S. K. 1974. Jurassic fossils of Western Australia, 1: Bajocian Bivalvia of the Newmarracarra Limestone and Kojerena Sandstone. - Bureau of Mineral Resources, Geology & Geophysics, Bulletin 150: 57-110, Melbourne. TrttJRMANN, J. & ETALLON, A. 1862. Lethea Bruntrutana. - Neue Denkschriften der allgemeinen schweizerischen Gesellschaft fiir Naturforschung 19: 146-353, Ziirich. Volts, H. E. 1980. Genera of Bivalvia: A systematic and bibliographic catalogue. - Paleontological Research Institute: 307 pp., Ithaca, N. Y. ZAKrtAROV,V. A. 1970. Late Jurassic and early Creataceous bivalves of northern Siberia and their ecology. Part 2, Family Astartidae. - Academy of sciences of the USSR, Sibirian Branch, Trudy Institute Geology Geophysics 113:136 pp., Moscow. [In Russian] Annahme des revidierten Manuskriptes durch die Schriftleitung am 17. 10. 1991.