Thapsia
Encyclopedia
Thapsia is a genus of air-breathing land snail
s, terrestrial
pulmonate gastropod mollusks in the family Helicarionidae
. This species is found in tropical western Africa, from Senegal
to Gabon
.
There is also a homonym
ous plant genus Thapsia belonging to the family Apiaceae
.
. These rather featureless dextral shells are characterized by a low spire
and their yellow to brown color. The spiral sculpture
of the postembryonic shell is slender. In some larger species the sculpture of the radial ribs is formed crosswise (like the letter X) or beadlike. The foot shows a long caudal horn.
of Nanina Gray, 1834, non Risso, 1826.
This genus is a heterogeneous assemblage. Because shell characters converge with the larger specimens of closely related genera (Saphtia Winter, 2008, Pseudosaphtia Winter, 2008 and Vanmolia Winter, 2008), the delimitation of species to Thapsia s.l. is difficult. There are only a few papers describing anatomical data of this genus.
Thapsia contains the following species:
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s, terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
pulmonate gastropod mollusks in the family Helicarionidae
Helicarionidae
Helicarionidae is a family of air-breathing land snails or semi-slugs, terrestrial pulmonate gastropod mollusks in the superfamily Helicarionoidea.- Distribution :...
. This species is found in tropical western Africa, from Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
to Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...
.
There is also a homonym
Homonym
In linguistics, a homonym is, in the strict sense, one of a group of words that often but not necessarily share the same spelling and the same pronunciation but have different meanings...
ous plant genus Thapsia belonging to the family Apiaceae
Apiaceae
The Apiaceae , commonly known as carrot or parsley family, is a group of mostly aromatic plants with hollow stems. The family is large, with more than 3,700 species spread across 434 genera, it is the sixteenth largest family of flowering plants...
.
Description
Species attributed to Thapsia s.l. have shell diameters ranging from about 15 to 30 mm. with 5½-6½ whorlsWhorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
. These rather featureless dextral shells are characterized by a low spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
and their yellow to brown color. The spiral sculpture
Sculpture (mollusc)
The sculpture of a mollusc shell is the three-dimensional ornamentation on the outer surface, as distinct from the basic shape of the shell itself or colouration. Sculpture may be concave as well as convex. Sometimes it has microscopic detail. Sculpture refers to the calcareous outer layer, not the...
of the postembryonic shell is slender. In some larger species the sculpture of the radial ribs is formed crosswise (like the letter X) or beadlike. The foot shows a long caudal horn.
Species
Thapsia was originally designated in 1860 by German zoologist Johann Christian Albers as a subgenusSubgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
of Nanina Gray, 1834, non Risso, 1826.
This genus is a heterogeneous assemblage. Because shell characters converge with the larger specimens of closely related genera (Saphtia Winter, 2008, Pseudosaphtia Winter, 2008 and Vanmolia Winter, 2008), the delimitation of species to Thapsia s.l. is difficult. There are only a few papers describing anatomical data of this genus.
Thapsia contains the following species:
- Thapsia buchholzi Bourguignat, 1885
- Thapsia buraensisThapsia buraensisThapsia buraensis is a species of air-breathing land snail or semi-slug, a terrestrial pulmonate gastropod mollusk in the family Helicarionidae. It is endemic to Kenya. Its natural habitat is subtropical or tropical dry forests. It is threatened by habitat loss.-References:* Lange, C. 2004. . ...
- Thapsia ebimimbangana Winter, 2008
- Thapsia grandisThapsia grandisThapsia grandis is a species of air-breathing land snail or semi-slug, a terrestrial pulmonate gastropod mollusk in the family Helicarionidae. It is endemic to Tanzania.-Source:* Tattersfield, P. 2000. . Downloaded on 7 August 2007....
- Thapsia microsculptaThapsia microsculptaThapsia microsculpta is a species of air-breathing land snail or semi-slug, a terrestrial pulmonate gastropod mollusk in the family Helicarionidae. It is endemic to Tanzania.-Source:* Tattersfield, P. 1996. . Downloaded on 7 August 2007....
- Thapsia rosenbergi Preston, 1909
- Thapsia snelliThapsia snelliThapsia snelli is a species of air-breathing land snail or semi-slug, a terrestrial pulmonate gastropod mollusk in the family Helicarionidae. It is endemic to Mauritius. There are 35 known species of Thapsia....
- Thapsia troglodytesThapsia troglodytesThapsia troglodytes is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicarionidae.Thapsia troglodytes is the type species of the genus Thaspia....
(Morelet, 1848) - type species, originally described as Helix troglodytes Morelet, 1848 - Thapsia usambarensisThapsia usambarensisThapsia usambarensis is a species of air-breathing land snail or semi-slug, a terrestrial pulmonate gastropod mollusk in the family Helicarionidae. It is endemic to Tanzania.-Source:* Tattersfield, P. 1996. . Downloaded on 7 August 2007....
- Thapsia wieringai Winter, 2008