Prestonella
Encyclopedia
Prestonella is a genus
of air-breathing land snail
s, terrestrial
pulmonate gastropod molluscs in the superfamily Orthalicoidea
.
Prestonella is the type genus of the family Prestonellidae, but Prestonellidae is not an available name
, because it has no diagnosis. Prestonella is the only genus in the family Prestonellidae.
in the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005
.
Herbert (2007) has classified Prestonella in Bulimulidae
sensu lato within Orthalicoidea.
Herbert & Mitchell (2009) have classified Prestonella, for which the phylogenetic relationships were previously unknown, in the superfamily Orthalicoidea
.
. It occurs in the southern edge of the Great Escarpment
in southern Africa.
Prestonella has a relict
distribution in the south of the southern Africa and it is the only Recent African member of Bulimulidae s.l. Its distribution is highly fragmented.
and Nama Karoo
(semi-desert) biomes. It is very specilized in habitat requirements and it inhabits only two types of relictual habitat
s: vertical-rocks above running water and moist shaded cliffs facing to the south. Prestonella occurs in the elevation 838-1680 m above sea level. There are two rainfall seasons in the area per year. It has been found in 2011, that genetic diversity
in the populations of Prestonella is lower in dryer areas. Global warming
would probably have serious negative impact on Prestonella species.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of air-breathing land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
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 molluscs in the superfamily Orthalicoidea
Orthalicoidea
The Orthalicoidea are a superfamily of air-breathing land snails, terrestrial gastropod mollusks in the informal group Sigmurethra.- 2005 taxonomy :...
.
Prestonella is the type genus of the family Prestonellidae, but Prestonellidae is not an available name
Available name
In zoology, an available name is a scientific name for a taxon of animals that has been published conforming to all the mandatory provisions of the ICZN Code for the establishment of a zoological name....
, because it has no diagnosis. Prestonella is the only genus in the family Prestonellidae.
Taxonomy
Prestonellidae was tentatively placed as a synonym of AillyidaeAillyidae
Aillyidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the informal group Sigmurethra.Aillyidae is the only family in the superfamily Aillyoidea....
in the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005
Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...
.
Herbert (2007) has classified Prestonella in Bulimulidae
Bulimulidae
Bulimulinae is a taxonomic subfamily of medium-sized to large, air-breathing, tropical and sub-tropical land snails, terrestrial pulmonate gastropod molluscs in the family Orthalicidae, according to the taxonomy of the Gastropoda ....
sensu lato within Orthalicoidea.
Herbert & Mitchell (2009) have classified Prestonella, for which the phylogenetic relationships were previously unknown, in the superfamily Orthalicoidea
Orthalicoidea
The Orthalicoidea are a superfamily of air-breathing land snails, terrestrial gastropod mollusks in the informal group Sigmurethra.- 2005 taxonomy :...
.
Distribution
This genus is endemic to South Africa and LesothoLesotho
Lesotho , officially the Kingdom of Lesotho, is a landlocked country and enclave, surrounded by the Republic of South Africa. It is just over in size with a population of approximately 2,067,000. Its capital and largest city is Maseru. Lesotho is a member of the Commonwealth of Nations. The name...
. It occurs in the southern edge of the Great Escarpment
Great Escarpment
The Great Escarpment is a mountainous escarpment in southern Africa. While it lies predominantly within the borders of Lesotho and South Africa, it also extends into Angola, Namibia, Swaziland, Mozambique, and Zimbabwe....
in southern Africa.
Prestonella has a relict
Relict
A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....
distribution in the south of the southern Africa and it is the only Recent African member of Bulimulidae s.l. Its distribution is highly fragmented.
Ecology
Prestonella lives in forestForest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
and Nama Karoo
Karoo
The Karoo is a semi-desert region of South Africa. It has two main sub-regions - the Great Karoo in the north and the Little Karoo in the south. The 'High' Karoo is one of the distinct physiographic provinces of the larger South African Platform division.-Great Karoo:The Great Karoo has an area of...
(semi-desert) biomes. It is very specilized in habitat requirements and it inhabits only two types of relictual habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s: vertical-rocks above running water and moist shaded cliffs facing to the south. Prestonella occurs in the elevation 838-1680 m above sea level. There are two rainfall seasons in the area per year. It has been found in 2011, that genetic diversity
Genetic diversity
Genetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary....
in the populations of Prestonella is lower in dryer areas. Global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
would probably have serious negative impact on Prestonella species.
Species
There are three species in the genus Prestonella:- Prestonella bowkeriPrestonella bowkeriPrestonella bowkeri is a species of air-breathing land snail, terrestrial pulmonate gastropod molluscs in the family Prestonellidae. cf.Prestonella bowkeri is the type species of the genus Prestonella.-Distribution:...
(Sowerby, 1889) - type species, synonym: Buliminus bowkeri - Prestonella nuptialisPrestonella nuptialisPrestonella nuptialis is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Prestonellidae. cf.-Distribution:This species is endemic to Eastern Cape, South Africa....
(Melvill & Ponsonby, 1894) - Prestonella quadingensis - validity of this species is doubtful Its habitat details are unknown.
Further reading
- Herbert D. G. & Mitchell A. (2004). "Prestonella, the missing African element in the Gondwanan family Bulimulidae (Mollusca, Pulmonata)". Paper presented at the IV Southern Connections Conference, Cape Town, 19-23.1.2004.