Genus of gastropods
Spironema
Temporal range: Cretaceous
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†Spironema
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†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]
Further reading
- Meek F. B. (1876). "A report on the Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri Country". Report of the United States Geological Survey of the territories, Washington, volume ix: i-ixv, 1-629, plates i-xlv. Spironema is on pages 341-343. Plate 32, figure 9a-c.
- Stephenson L. W. (1941). The larger invertebrate fossils of the Navarro group of Texas. The University of Texas Publication 4101: 1-625.