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|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Bivalvia - Protobranchia - Ctenodontidae
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If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|H. Soot-Ryen and T. Soot-Ryen 1960||Shell small, rounded triangular, slightly langer than high. Umbones full but not much inflated, opisthogyre. Umbonal angle blunt. Anterodorsal margin curvcd and inflected with a more or less distinct anteroventral angle, ventral margin rounded and posteroventral corner broadly rounded. Posterodorsal margin concave to straight with the lower part somewhat protruding. Parallel to the anterodorsal margin there is a more or less distinct sulcus. Sculpture consisting of somewhat irregular concentric lines with broad interspaces, 5-6 lines on 2 mm in the middle part of the valve. On the internal casts there are several growth lines along the margins. Ringe teeth in two series (textfig. 1) , c.9 proximal anterior teeth, lamelliform and nearly vertical to the hinge margin. 14 distal teeth larger, angular and more oblique to the hinge margin. Proximal posterior teeth short, about 3-5, distal 8 teeth large obliquely set and angulated. The region beneath the umbo is not complete, but there seems to be a flat or slightly concave part just where the two series of tecth mect. The anterior adductor scar is elongate and placed rather low, the posterior adductor scar distinct, ovate and placed below the distal tooth. Pallial line entire. Length 13.2 mm, height 12.6 mm, semidiameter c. 2 mm.|