Propeamussium (Propeamussium) sp.

Fuersich, Franz T., Alberti, Matthias, Pandey, Dhirendra K. & Ayoub-Hannaa, Wagih S., 2022, Jurassic bivalves from the Spiti area of the Himalayas, northern India, Zitteliana 96, pp. 153-178 : 153

Propeamussium (Propeamussium) sp.

Plate 3, fig. 12

Material.

One internal mould of a single valve (SNSB-BSPG 2020 XCIX 12) and several small fragments from the lower member at Langza.

Description and remarks.

The internal mould of a fragment displays seven radial grooves, which correspond to internal ribs. The complete shell might have carried 8-9 ribs. These ribs end just before the ventral margin.

While the specimen undoubtedly can be referred to P. (Propeamussium) , identification at the species level is impossible. The only Upper Jurassic species recognized by Johnson (1984) is P. (P.) nonarium (Quenstedt, 1858, p. 795, pl. 98, fig. 4), which is restricted to Europe and differs from the present specimen by relatively short internal ribs, which end well before the ventral margin.

Order Limida Moore, 1952

Figures

Plate 3. (1, 2) Bositra buchii (Roemer, 1836). Composite moulds from the lower member at Langza. 1. a, articulated specimen in butterfly position, dorsal view (SNSB-BSPG 2020 XCIX 18 a); b, c, single valves, lateral view (SNSB-BSPG 2020 XCIX 18 b). 2. External mould of right valve (SNSB-BSPG 2020 XCIX 19). (3) Australobuchia spitiensis (Holdhaus, 1913). Composite mould of articulated specimen from the middle member, roadside close to Komic; right valve view (SNSB-BSPG 2020 XCIX 43). (4 - 5) Australobuchia blanfordiana (Stoliczka, 1866). upper member close to Demul Pass. 4. Right valve (SNSB-BSPG 2020 XCIX 46). 5. Right valve (SNSB-BSPG 2020 XCIX 45). (6 - 10)? Malayomaorica sp. upper member close to Demul Pass. 6. Left valve (SNSB-BSPG 2020 XCIX 51 a). 7. Right valve interior (SNSB-BSPG 2020 XCIX 52). 8. Fragment of right valve (SNSB-BSPG 2020 XCIX 51 b). 9. Left valve (SNSB-BSPG 2020 XCIX 51 c). 10. Fragment of right valve (SNSB-BSPG 2020 XCIX 51 d). (11) Entolium (Entolium) corneolum (Young & Bird, 1822). Internal mould of a left valve from the lower member at Langza (SNSB-BSPG 2020 XCIX 15). (12) Propeamussium (Propeamussium) sp. Internal mould of a small fragment from the lower member at Langza (SNSB-BSPG 2020 XCIX 12). a, natural size; b, enlarged. (13) Camptonectes (Camptochlamys) obscurus (J. Sowerby, 1818). Left valve interior from the lower member near the pass to Tashigeng (SNSB-BSPG 2020 XCIX 13).