Kolmeris Pérez & Del Río 2017, new genus
Genus Kolmeris new genus Type species. Venericardia tehuelchana Ihering, 1907 (pl. 16, figs 107a–b). Surroundings of Cerro Laciar (Feruglio 1954), lower Pliocene, Santa Cruz, Argentina. Diagnosis. Carditid with small (less than 30 mm in length) and high shell with subtriangular outline and a convex...
Main Authors: | , |
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Format: | Other/Unknown Material |
Language: | unknown |
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2017
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Online Access: | https://zenodo.org/record/6030275 https://doi.org/10.5281/zenodo.6030275 |
Summary: | Genus Kolmeris new genus Type species. Venericardia tehuelchana Ihering, 1907 (pl. 16, figs 107a–b). Surroundings of Cerro Laciar (Feruglio 1954), lower Pliocene, Santa Cruz, Argentina. Diagnosis. Carditid with small (less than 30 mm in length) and high shell with subtriangular outline and a convex dorsal margin. Left anterior tooth large and vertical, right middle tooth small and slightly inclined posteriorly. External sculpture of 9 to 15 low, smooth and flat radial ribs, widening towards the central region of the valve with wide intercostal spaces. Included species. Venericardia (Pleuromeris) marshalli Marwick, 1924 (upper Pliocene–Recent, Petane Clays, New Zealand), Pleuromeris murdochi Powell, 1938 (upper Pliocene, Castle Point, New Zealand), Pleuromeris paucicostata Laws, 1940 (upper Pliocene–Recent, Nukumaru, New Zealand). Derivation of name. From ‘ kol ’ (Aonikenk, original language of the Aonikenk or Tehuelche’s people, early inhabitants of Santa Cruz Province) that means ‘seashell’, and ‘- meris ’, a common suffix employed for small carditids and which probably comes from Latin word ‘ maris ’ that means ‘from the sea’. Remarks. Kolmeris n. gen. shares characters with Pleuromeris and Pteromeris Conrad, 1862 (type species Cardita perplana Conrad, 1841; Pliocene–Recent of North Atlantic Ocean) (Gardner 1943: pl. 13, figs 6–9) such as their small and subtriangular shell, pointed umbo, large lunule, right middle tooth being triangular and vertical and a sculpture of usually less than 20 wide radial ribs. The new genus can be separated from Pleuromeris by having a higher shell with convex dorsal margin, less pointed umbo, a larger right anterior tooth and fewer, lower and wider radial ribs not covered by nodes. It can be distinguished from Pteromeris by the absence of the typical recurved and anteriorly directed umbo that characterizes this genus, the presence of a smaller right middle tooth and straight left posterior tooth, and by the development of wider intercostal spaces. Kolmeris differs from Coripia ... |
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