Nucinella nakremi Foster & Danise & Twitchett 2017, sp. nov. ...
Nucinella nakremi sp. nov. (Fig. 4) Diagnosis. A small Nucinella having a nuculoid shape, smooth shell except for growth lines. Prosogyrate beak, one to three subumbonal teeth. Ligament amphidetic and does not invade the hinge plate. Holotype. Disarticulated left valve, NHMUK PI MB 1219, LD-04; leng...
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Format: | Text |
Language: | unknown |
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Zenodo
2016
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Online Access: | https://dx.doi.org/10.5281/zenodo.10883096 https://zenodo.org/doi/10.5281/zenodo.10883096 |
Summary: | Nucinella nakremi sp. nov. (Fig. 4) Diagnosis. A small Nucinella having a nuculoid shape, smooth shell except for growth lines. Prosogyrate beak, one to three subumbonal teeth. Ligament amphidetic and does not invade the hinge plate. Holotype. Disarticulated left valve, NHMUK PI MB 1219, LD-04; length = 1.1 mm, height = 1.1 mm. Paratype. Disarticulated left valve, NHMUK PI MB 1220, LD-04; length = 0.9 mm, height = 0.8 mm (transposed hinge). Other material. Two specimens from LD-04 (NHMUK PI MB 1221–1222). Derivation of name. Named after Dr Hans Arne Nakrem in recognition of his work on Permian and Triassic fossils from Svalbard. Description. Shell small, nuculoid and ovate. Posterior dorsal margin distinct, slightly incurved; posterior margin rounded. Inequilateral, prosogyrate, with beaks close to anterior margin. Umbo prominent. Smooth, thin shell with very weak growth lines. Monomyarian: posterior adductor muscle scar absent; anterior adductor large, oval. One to two subumbonal, pointed blade-like teeth ... : Published as part of Foster, William J., Danise, Silvia & Twitchett, Richard J., 2017, A silicified Early Triassic marine assemblage from Svalbard, pp. 851-877 in Journal of Systematic Palaeontology 15 (10) on pages 857-858, DOI: 10.1080/14772019.2016.1245680, http://zenodo.org/record/10883052 ... |
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