Tucetona wairarapaensis
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| Tucetona wairarapaensis Temporal range: | |
|---|---|
 | |
| Holotype from Auckland War Memorial Museum | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Arcida |
| Family: | Glycymerididae |
| Genus: | Tucetona |
| Species: | †T. wairarapaensis |
| Binomial name | |
| †Tucetona wairarapaensis (A. W. B. Powell, 1938) | |
| Synonyms | |
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Tucetona wairarapaensis is an extinct species of bivalve, a marine gastropod in the family Glycymerididae.[1] Fossils of the species date to the early Pleistocene strata of the Castlepoint Formation at Castlepoint, Wairarapa, New Zealand. The species may have descended from the Miocene (Waiauan stage) species T. monsadusta, and be ancestral to modern-day T. laticostata.
In the original description, Powell described the species as follows:
Shell large, very massive, well inflated, almost equilateral and narrowly subovate in outline. Sculpture consisting of from 36 to 39 convex well raised radial ribs with linear interstices. (The holotype has 36 radials). In adult specimens the radials become obsolete at the ventral margin. Hinge plate massive and narrowly arched, with a few strong anterior and posterior chevroned teeth, separated by a wide smooth space in the middle portion of the hinge plate. In the adult shell there are six anterior and the same number of posterior teeth. Ligamental area short and moderately deep, with six chevrons.[2]
The holotype of the species has a height of 63.5 mm (2.50 in), a length of 60 mm (2.4 in) and a thickness of 22 mm (0.87 in) for a single valve.[2] It can be distinguished from T. monsadusta due to having more numerous radial ribs and fewer ligamental chevrons, and from T. laticostata by being more oval and having a more convex shell, as well as by its narrowly arched massive hinge-plate.[2]
