Emarginula haweraensis
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| Emarginula haweraensis Temporal range: | |
|---|---|
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| Holotype from Auckland War Memorial Museum | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Vetigastropoda |
| Order: | Lepetellida |
| Family: | Fissurellidae |
| Genus: | Emarginula |
| Species: | E. haweraensis |
| Binomial name | |
| Emarginula haweraensis A. W. B. Powell, 1931 | |
Emarginula haweraensis is an extinct species of limpet, a marine mollusc in the family Fissurellidae.[1] Fossils of the species date to between the Waipipian stage (3.70 million years ago) of the late Pliocene, and the Pleistocene Castlecliffian stage (1.63 million years ago) in New Zealand. The largest known species of Emarginula known from New Zealand, fossils of the species are widely distributed around the country.
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In the original description, Powell described the species as follows:
Shell very large, broadly ovate and spreading. Elevation moderate; apex recurved and situated at the posterior three-eighths. Sculpture consisting of moderately strong radials crossed by fine concentric cords. The radials are approximately equal in number to those of striatula, but differ in their development. Both primary and secondary radials are more nearly equal in size and have a tendency to become broader and flatter towards the margin, resulting in only linear interspaces. For this reason it is a difficult matter to sort out primary cords in the adult shell, but a half-grown paratype shows about 44. Furthermore, owing to these linear interspaces the concentric cords merely delicately imbricate the radials; definite reticulation being apparent only in the vicinity of the apex. In the holotype there are about 118 definite radials at the margin (including both primaries and secondaries), of which 86 extend to the apical area.[2]
The holotype of the species has a length of 42.0 mm (1.65 in), a breadth of 33.75 mm (1.329 in), and a height of 17.0 mm (0.67 in).[2] It is the largest known New Zealand species of Emarginula.[3]
