Jurassic bivalves from the Spiti area of the Himalayas, northern India
Author
Fuersich, Franz T.
https://orcid.org/0000-0002-0844-9297
Universitaet Erlangen-Nuernberg, GeoZentrum Nordbayern, FG Palaeoumwelt, Lowenichstrasse 28, 91054 Erlangen, Germany
franz.fuersich@fau.de
Author
Alberti, Matthias
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Centre for Research and Education on Biological Evolution and Environment and Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, China
Author
Pandey, Dhirendra K.
https://orcid.org/0000-0002-7721-9604
Department of Earth and Environmental Science, KSKV Kachchh University, Bhuj, India
Author
Ayoub-Hannaa, Wagih S.
Geology Department, Faculty of Science, Minufiya University, El-Minufiya, Shibin El Kom, Egypt
text
Zitteliana
2022
2022-08-11
96
153
178
http://dx.doi.org/10.3897/zitteliana.96.87253
journal article
http://dx.doi.org/10.3897/zitteliana.96.87253
2747-8106-96-153
191199E07F3E4E09A3774ADFBF93A248
AFA9059B36235BFF9BA3E9B7BE816DC1
Nicaniella (Nicaniella) cf. polymorpha (Contejean, 1860)
Plate 5, fig. 7a-d
cf. 1860 Astarte polymorpha
Contej. - Contejean: 266, pl. 11, figs 13-16.
Material.
A single articulated specimen from the lower member, Kaza-Hikkim road (SNSB-BSPG 2020 XCIX 42).
Plate 5.
(1-6)
Pruvostiella (Pruvostiella) hermanni
(Oppel, 1863).
1.
Crushed articulated specimen from the lower member at Langza (SNSB-BSPG 2020 XCIX 53). a, left valve view; b, dorsal view.
2.
Crushed articulated specimen from the lower member close to the pass to Tashigeng (SNSB-BSPG 2020 XCIX 54a). a, left valve view; b, right valve view.
3.
Crushed articulated specimen from the lower member at the Kaza-Hikkim road cut (SNSB-BSPG 2020 XCIX 55a).
4.
Articulated specimen from the lower member at Langza (SNSB-BSPG 2020 XCIX 59b). a, right valve view; b, left valve view.
5.
Articulated specimen from the lower member close to the pass to Tashigeng (SNSB-BSPG 2020 XCIX 54b). a, right valve view; b, dorsal view; c, left valve view.
6.
Crushed articulated specimen from the lower member at the Kaza-Hikkim road cut (SNSB-BSPG 2020 XCIX 55b).
(7)
Nicaniella (Nicaniella) cf. polymorpha
(Contejean, 1860). Articulated specimen from the lower member at the Kaza-Hikkim road cut (SNSB-BSPG 2020 XCIX 42). a, right valve view, natural size; b, enlarged; c, dorsal view; d, left valve view.
(8)
Cryptocardia
sp. Right internal mould with remains of shell from the lower member close to the pass to Tashigeng (SNSB-BSPG 2020 XCIX 40).
(9)
Integricardium (Integricardium) bannesianum
(Contejean, 1860). Right internal mould with remains of shell from the Ferruginous Oolite Formation near Zangla (SNSB-BSPG 2020 XCIX 41). a, lateral view; b, dorsal view.
Description.
Specimen small-sized (H: 9.1 mm; L: 9.7 mm), rounded-triangular, slightly longer than high, moderately inflated. Anterodorsal margin concave, anteroventral margin convex, ventral margin faintly curved, posterodorsal margin long, straight, sloping, forming a rounded angle with the slightly truncated posteroventral margin. Umbones mesial, conspicuous, prosogyrate. Lunule oval, deeply sunk, bordered by sharp carina. Escutcheon long, lanceolate, sharply demarcated, extending to posterior end. Ventral shell margin strongly crenulated. Shell surface covered with 22 closely set, sharp commarginal ribs which are more widely spaced in the umbonal area. Internal features not seen.
Remarks.
Among the numerous Jurassic species of
Nicaniella
, the specimen is closest to
Nicaniella polymorpha
(Contejean,1860: 266, pl. 11, figs 13-16) from the Kimmeridgian of eastern France in outline and ornamentation, but that species is known only from its drawings. Therefore, we place our specimen in this species with reservation.
Order Cardiida Ferrusac, 1822