Malletiidae Adams & Adams 1858 ...
Family Malletiidae Adams & Adams, 1858 gen. et sp. indet. (Fig. 7) Diagnosis. Subequilteral to inequilateral; usually with elongate, compressed posterior end; sculpture of commarginal striae or ribs; anterior and posterior gapes present; hinge plate weak, with fine taxodont teeth in two series,...
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| Format: | Text |
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Zenodo
2016
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| Online Access: | https://dx.doi.org/10.5281/zenodo.10903520 https://zenodo.org/doi/10.5281/zenodo.10903520 |
| Summary: | Family Malletiidae Adams & Adams, 1858 gen. et sp. indet. (Fig. 7) Diagnosis. Subequilteral to inequilateral; usually with elongate, compressed posterior end; sculpture of commarginal striae or ribs; anterior and posterior gapes present; hinge plate weak, with fine taxodont teeth in two series, sometimes separated by plain area, without resilifer; ligament external, opisthodetic to amphidetic, weak; pallial sinus large. Material. Three larval shells from LD-04 (NHMUK PI MB 1248–1250). Description. Shell is equilateral, elliptical, H/L ratio of 0.7, and moderately inflated. Umbo is broad, orthogyrate, with beak positioned centrally. Shell smooth except for concentric growth lines. Hinge plate has three anterior and three posterior teeth in two series separated by a large plain area with a groove. Ligament is predominantly external, amphidetic and weak. Remarks. Malletiidae are very similar to Nuculanidae, but the lack of a resilifer in mature adults supports their separation (Coan & Valentich-Scott ... : 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 861-862, DOI: 10.1080/14772019.2016.1245680, http://zenodo.org/record/10883052 ... |
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