Pectinida Gray 1854

• Main Authors: Hryniewicz, Krzysztof, Little, Crispin T. S., Nakrem, Hans Arne
• Format: Text
• Language: unknown
• Published: Zenodo 2014
• Subjects: Biodiversity; Taxonomy; Animalia; Mollusca; Bivalvia; Pectinida; Arctic; Svalbard; Baja; Todd; Bertrand; Palermo; Alaska; Spitsbergen
• Online Access: https://dx.doi.org/10.5281/zenodo.4929779; https://zenodo.org/record/4929779

Pectinida gen. et sp. indet. (Figure 10 A–B) 2011 Ostreoidean—Hammer et al ., tab. 2. Material examined. Five specimens; fragmented and delaminated shells. See Appendix 1 for the list of specimens. Description. Shell thin, roughly round in shape, only weakly inflated. Right valve thin, flat, visible only in cross-section. Left valve thin, weakly convex and larger than right valve; irregularly shaped, no sign of attachment found. Beak weakly incurved, accompanied by a shallow ventrally directed furrow. Weak muscle scar probably represent an adductor muscle scar. Shell ornamented by weak commarginal folds. Remarks. The lack of a well demarcated external ligament, the thinness of the shells and the nature of cementation precludes our specimens belonging to the Ostreida Férrusac, 1822. Instead, the flat right valve facing the substrate and a larger covering left valve indicates that our specimens belong either to the Anomiidae Rafinesque, 1815, or the Dimyidae, Fischer, 1886 (e.g. Coan et al. 2000; Coan & Scott 2012). An anomiid origin is probably more likely because the dorsal furrow resembles the shell fusion scar characteristic for anomiids (Yonge 1977). However, the lack of well preserved right valves and adductor muscle scars means we cannot unequivocally include our specimens into either the Anomiidae and Dimyidae at present. Palaeoecology. Our species was most likely a filter-feeder attached to hard substrates. Modern anomiids are shallow water forms, attached by a byssus protruding through a foramen in the lower valve (e.g. Yonge 1977). Recent Dimyidae is a cementing group found in deep water and cryptic habitats (e.g. Waller 2012). In the Mesozoic both groups were fairly common in shallow water habitats (e.g. Fürsich & Werner 1989; Hodges 1991; Todd & Palmer 2002). : Published as part of Hryniewicz, Krzysztof, Little, Crispin T. S. & Nakrem, Hans Arne, 2014, Bivalves from the latest Jurassic-earliest Cretaceous hydrocarbon seep carbonates from central Spitsbergen, Svalbard, pp. 1-66 in Zootaxa 3859 (1) on page 22, DOI: 10.11646/zootaxa.3859.1.1, http://zenodo.org/record/4930112 : {"references": ["Ferrusac, A. E. de. (1822) Tableaux systematiques des animaux mollusques. A. Bertrand, Paris, 111 pp.", "Rafinesque, C. S. (1815) Analyse de la nature. De l'imprimerie de Jean Barravecchia, Palermo, 225 pp.", "Fischer, P. (1886) Manuel de Conchyliologie et de paleontologie conchyliologique ou histoire naturelle des mollusques vivants et fossils. 10. Classes des pelecypodes. F. Savy, Paris, 897 - 1008. http: // dx. doi. org / 10.5962 / bhl. title. 13213", "Coan, E. V., Scott, P. V. & Bernard, F. R. (2000) Bivalve seashells of Western North America. Marine bivalve molluscs from Arctic Alaska to Baja California. Santa Barbara Museum of Natural History Monographs, 2, vii + 764 pp.", "Coan, E. V. & Scott, P. V. (2012) Bivalve seashells of tropical West America. Marine bivalve molluscs from Baja California to Northern Peru. Santa Barbara Museum of Natural History Monographs, 4, vii + 1258 pp.", "Yonge, C. M. (1977) Form and evolution in the Anomiacea (Mollusca: Bivalvia) - Pododesmus, Anomia, Patro, Enigmonia (Anomiidae): Placunanomia, Placuna (Placunidae Fam. Nov.). Philosophical Transactions of the Royal Society of London B, 276, 453 - 523. http: // dx. doi. org / 10.1098 / rstb. 1977.0005", "Waller, T. R. (2012) Morphology, phylogeny, and systematic revision of genera in the Dimyidae (Mollusca, Bivalvia, Pteriomorphia). Journal of Paleontology, 86, 829 - 851. http: // dx. doi. org / 10.1666 / 12 - 004.1", "Fursich, F. T. & Werner, W. (1989) Taxonomy and ecology of Juranomia calcibyssata gen. et sp. nov, a widespread anomiid bivalve from the Upper Jurassic of Portugal. Geobios, 22, 325 - 337. http: // dx. doi. org / 10.1016 / s 0016 - 6995 (89) 80135 - 4", "Hodges, P. (1991) The relationship of the Mesozoic bivalve Atreta to the Dimyidae. Palaeontology, 34, 963 - 970.", "Todd, J. A. & Palmer, T. J. (2002) The Jurassic bivalve genus Placunopsis: new evidence on anatomy and affinities. Paleontology, 45, 487 - 510. http: // dx. doi. org / 10.1111 / 1475 - 4983.00247"]}