Spironema (gastropod)
Genus of gastropods
From Wikipedia, the free encyclopedia
Spironema is a genus of extinct (Cretaceous) sea snails, marine gastropod mollusks in the family Naticidae, the moon snails.[1]
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| Genus: | †Spironema |
Description
The American paleontologist Fielding Bradford Meek firstly defined this genus in 1864.[2] He classified the genus in the family Littorinidae.[2] He recognized two species Spironema bella and Spironema tenuilineata in 1864.[2] These species were previously classified within the family Trochidae.[2] Meek's diagnosis reads as follows:[2]
Shell ovate; whorls rounded, and separated by a rather deep
suture; aperture ovate, lip thin, continuous; columella not thickened, perforated by a very small umbilicus; surface with revolving lines and furrows. The non-perlaceous texture of the interior layer, as well as the other characters of such Cretaceous
shells, remove them from the Trochidae.
Species
Species within the genus Spironema include:
- Spironema bella (Conrad) - synonym: Tuba (?) bella Conrad, from Cretaceous of Alabama[2]
- Spironema tenuilineata (Meek & Hayden, 1856) - from Cretaceous of Dakota Territory, type species: Turbo tenuilineatus Meek & Hayden, 1856[2][3] - synonym: Turbo tenuilineata
- Spironema perryi Stephenson - from Maastrichtian, Texas.[4] Spironema cf. perryi is also known from the Upper Cretaceous, Cliff House Sandstone, Chaco Canyon, northwestern New Mexico.[1]