Spironema (gastropod)

Spironema
Temporal range: Cretaceous
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Caenogastropoda
clade Hypsogastropoda
clade Littorinimorpha
Superfamily: Naticoidea
Family: Naticidae[1]
Genus: Spironema
Meek, 1864[2]

Spironema is a genus of extinct (Cretaceous) sea snails, marine gastropod mollusks in the family Naticidae, the moon snails.[1]

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:

References

This article incorporates public domain text from the reference[2]

  1. 1 2 3 Siemers C. T. & King N. R. (1974). "Macroinvertebrate paleoecology of a transgressive marine sandstone, Cliff House Sandstone (Upper Cretaceous), Chaco Canyon, northwestern New Mexico". New Mexico Geol. Soc. Guidebook, 25th Field Conf., Ghost Ranch (Central-Northern N.M.): 267-277. PDF.
  2. 1 2 3 4 5 6 7 8 9 Meek F. B. (1864). "Check list of the invertebrate fossils of North America. Cretaceous and Jurassic". Smithsonian Miscellaneous Collections 7(177): 1-40. page 19, page 35.
  3. Meek F. B. & Hayden F. V. (1856). "Descriptions of new species of Gastropoda from the Cretaceous formations of Nebraska Territory". Proceedings of the Academy of Natural Sciences of Philadelphia 8: 63-69. page 64.
  4. "USGS 07545: Maastrichtian, Texas". The Paleobiology Database, accessed 11 August 2011.

Further reading

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