Goniomya literata

Goniomya literata (J. Sowerby, 1819) (Figure 19 A–B) 1819 Mya ? literata —J. Sowerby, p. 45, pl. 224, fig. 1. 1931 Goniomya arctica nov. sp. —Sokolov & Bodylevsky, p. 76, pl. 4, fig. 8. 1934 Goniomya literata (J. Sowerby) —Arkell, p. 344, pl. 47, figs. 1–7 and references therein.? 1982 Goniomya...

Full description

Bibliographic Details
Main Authors: Hryniewicz, Krzysztof, Little, Crispin T. S., Nakrem, Hans Arne
Format: Other/Unknown Material
Language:unknown
Published: 2014
Subjects:
Online Access:https://zenodo.org/record/5228286
https://doi.org/10.5281/zenodo.5228286
Description
Summary:Goniomya literata (J. Sowerby, 1819) (Figure 19 A–B) 1819 Mya ? literata —J. Sowerby, p. 45, pl. 224, fig. 1. 1931 Goniomya arctica nov. sp. —Sokolov & Bodylevsky, p. 76, pl. 4, fig. 8. 1934 Goniomya literata (J. Sowerby) —Arkell, p. 344, pl. 47, figs. 1–7 and references therein.? 1982 Goniomya cf. dubois Agassiz—Birkenmajer et al., pl. 43, fig. 5. 1982 Goniomya literata (Sowerby) —Fürsich, p. 98, figs. 35e, 36 c–d. 1985 Goniomya literata (Sowerby) —Bäckström & Nagy, p. 35, pl. 5, figs. 1–2 and references therein. 2011 Goniomya sp. —Hammer et al., tab. 2. Material examined. Three internal moulds with small pieces of shell. See Appendix 1 for list of specimens. Description. Shell small to medium, elongated, outline ovoid; no carina. Umbonal area positioned submedialy. Umbones not preserved. Ornament of up to 13 ventrally directed chevrons, with ridges and depressions between them roughly equal in size. Chevron ridges gently rounded with both ventral and dorsal slopes inclined at an equal angle. At younger growth stages tips of chevrons often blunt so whole ornament is trapezoidal or w-shaped. Line transecting tips of chevrons slightly inclined towards shell posterior. Angle between chevron limbs between 85 and 95 degrees. Chevron ornament transected by weak, concentric growth lines. Pallial line unknown. Remarks. The oval shape of our specimens with almost equilaterally positioned beaks puts them into Goniomya literata (J. Sowerby, 1819) (e.g. Arkell 1934; Fürsich 1982). The Svalbard specimens differs from G. bicarinata Fürsich, 1982, from Greenland, which has a much longer posterior and two distinct carinae running from the umbo towards the anteroventral and posteroventral margins, respectively. Occurrence. Seeps 3 and 9 (Upper Volgian–uppermost Ryazanian), Slottsmøya Member, Svalbard (Tab. 1). Goniomya literata is relatively wide-spread (Hallam 1976) and is known from the Middle Jurassic of England (e.g. Arkell 1934), Lithuania (Krenkel 1915), Spitsbergen (Bäckström & Nagy 1985) and the Upper ...