Neoplanorbis tantillus

Neoplanorbis tantillus
Three views of a shell of Neoplanorbis tantillus
Conservation status
Critically Endangered (IUCN 2.3)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Heterobranchia clade Euthyneura clade Panpulmonata clade Hygrophila
Superfamily:	Planorboidea
Family:	Planorbidae
Subfamily:	Neoplanorbinae
Genus:	Neoplanorbis
Species:	N. tantillus
Binomial name
Neoplanorbis tantillus Pilsbry, 1906[2]

Neoplanorbis tantillus is a species of very small air-breathing freshwater snail, an aquatic gastropod mollusk in the family Planorbidae, the ram's horn snails. This species is endemic to the United States.

The shells of this species appear to be dextral in coiling, but as is the case in all planorbids, the shell is actually sinistral. The shell is carried upside down with the aperture on the right, and this makes it appear to be dextral.

Original description

Species Neoplanorbis tantillus was originally described by Henry Augustus Pilsbry in 1906.^[2]

Type locality is Coosa River near or in Wetumpka, Alabama.

Pilsbry's original text (the type description) reads as follows:

“

Neoplanorlis tantillus n. sp. PI. III, figs. 3, 4, 5. Shell very narrowly perforate, slightly convex above, very convex below, with a strongly projecting rounded keel at the periphery; light brown; surface slightly shining, sculptured with very obliquely radial growth-lines and raised spiral stride, rather coarse for a shell of this size. Whorls 2, rapidly enlarging, the apex somewhat sunken; first whorl very convex, the second much less so, slowly descending in front. Aperture very oblique, shaped like a gothic-arched door, the upper and lower margins arcuate, the outer margin angular, the columellar margin dilated, straight and vertical, with a rather wide whitish callous within. Alt. .8, diam. 1.7 mm. The specimens occurred at Wetumpka, Alabama with the preceding species. This is one of the smallest fresh-water mollusks yet found in America.

”

Note: "preceding species" in the description means Amphigyra alabamensis, because these two species were newly described in the same work.

References

1. ^ Bogan A. E. (1996). Neoplanorbis tantillus. In: IUCN 2008. 2008 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 27 November 2008.
2. ^ ^{a b} Pilsbry H. A. (September 1906). "Two new American genera of Basommatophora". The Nautilus 20(5): 49-51.