Athearnia crassa

Athearnia crassa
Shell of Athearnia crassa (specimen at the Smithsonian Institution)
Conservation status
Extinct  (IUCN 2.3) [1]
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Family:	Pleuroceridae
Genus:	Athearnia
Species:	†A. crassa
Binomial name
†Athearnia crassa (Haldeman, 1841)
Synonyms
Anculosa anthonyiRedfield, 1854 (junior synonym) Anculosa crassaHaldeman, 1842 (original combination) Anculosa turbinataI. Lea, 1861 (junior synonym) Eurycaelon crassaHinkley, 1906 (original combination) Leptoxis crassa(Haldeman, 1842) Leptoxis pisumHaldeman, 1847 (junior synonym)

Athearnia crassa, the boulder snail, was a species of freshwater snail in the family Pleuroceridae. ^[2]

Description

(Original description) The shell is either conical or globose in shape and possesses a ponderous structure. It consists of five whorls, which are either flat or slightly convex. The spire is notably exserted, and the aperture is ovate, featuring a well-marked columellar notch. The outer lip is thick, and the overall color of the shell is brown.

The specimen typically reaches a length of 3 inches (76.2 mm) and its habitat is the Clinch River in Tennessee. This species differs from Anculosa praerosa(Say, 1821) (synonym of Leptoxis praerosa (Say, 1821) by its more highly developed spire and its more distinct notch. ^[3]

Distribution

It was^{[ when? ]} native to the United States, where it was known from Alabama, Georgia, Tennessee, and Virginia. It is now extinct. ^[1]

References

1. Mollusc Specialist Group (1996). "Athearnia crassa". IUCN Red List of Threatened Species . 1996 e.T11768A3304335. doi: 10.2305/IUCN.UK.1996.RLTS.T11768A3304335.en . Retrieved 15 November 2021.
2. Athearnia crassa (Haldeman, 1842) . 23 December 2025. Retrieved through: World Register of Marine Species .
3. Haldeman, S.S. (1842). New species of shells. A monograph of the Limniades or freshwater univalve shells of North America. Philadelphia: J. Dobson. Retrieved 23 December 2025. This article incorporates text from this source, which is in the public domain .

• Haldeman, S.S. (1847). G. Leptoxis, Leptoxe, Rafinesque. In: Illustrations conchyliologiques ou description et figures de toutes les coquilles connes vivantes et fossiles, classées suivant le système de Lamarck modifié d’après les progrès de la science, et comprenant les genres nouveaux et les espèces récemment découvertes. Part 73. Ed: Chenu, J.C. A. Franck, Paris. plates 2-3.

External links

• Haldeman, S. S. (1842). New species of shells. A monograph of the Limniades or freshwater univalve shells of North America. 4. J. Dobson, Philadelphia
• Lea, I. (1861). Descriptions of new species of Schizostoma, Anculosa and Lithasia. Proceedings of the Academy of Natural Sciences of Philadelphia. 13: 54-55
• Redfield, J.H. (1854). Descriptions of new species of shells; Annals of the Lyceum of Natural History of New York. 6: 130-132, plate 1
• Johnson, P. D.; Bogan, A. E.; Brown, K. M.; Burkhead, N. M.; Cordeiro, J. R.; Garner, J. T.; Hartfield, P. D.; Lepitzki, D. A. W.; Mackie, G. L.; Tarpley, T. A.; Tiemann, J. S.; Whelan, N. V.; Strong, E. E. (2013). Conservation status of freshwater gastropods of Canada and the United States. Fisheries. 38(6): 247-282