Pleuromeris hectori
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| Pleuromeris hectori Temporal range: | |
|---|---|
 | |
| Holotype from Auckland War Memorial Museum | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Carditida |
| Family: | Carditidae |
| Genus: | Pleuromeris |
| Species: | P. hectori |
| Binomial name | |
| Pleuromeris hectori A. W. B. Powell, 1938 | |
Pleuromeris hectori is a species of marine bivalve mollusc in the family Carditidae.[1] It is endemic to New Zealand, found primarily off the north-eastern coast of the North Island. Fossils of the species date back to at least the Nukumaruan stage of the Early Pleistocene (2.4 million years ago).
In the original description, Powell described the species as follows:
Shell moderately large, subcircular, subequilateral, beaks almost central, high and rounded. Lunule flattened, large, lanceolate and smooth. Escutcheon long and narrow, smooth. Sculptured with eighteen prominent broad, flattened, regularly beaded radial ribs with interspaces less than half the width of the ribs. Hinge of left valve with two strong divergent cardinals forming an angle of about 65°; both cardinals separated from the dorsal margins. Anterior and posterior laterals present. Hinge of right valve with a massive triangular median cardinal and anterior and posterior rudimentary cardinals. Anterior and posterior laterals present.[2]
The holotype of the species has a height of 12.75 mm (0.502 in), length of 12.5 mm (0.49 in) and a single valve thickness of 4 mm (0.16 in).[2] It is large for New Zealand members of Pleuromeris, and has a slightly protruding umbo in front of the centre. Radial costae typically number between 20 and 24.[3]
It can be differentiated from P. zelandica due to having a different outline and sculpture, being more rotund, having more numerous and boarder ribs with narrower interspaces.[2]
