''Crenadactylus occidentalis'', also called the western clawless gecko, is a species of

gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos ar ...

endemic to the western coast of Australia.

Taxonomy

''Crenadactylus occidentalis'' was first described in a taxonomic revision in 2016 of rare and poorly known geckos of the genus '' Crenadactylus'', assembling evidence of greatly under-estimated speciation previously only recognised as subspecies of monotypic genus. One of four new species to emerge from molecular studies that had reported chromosomal distinctions that indicated the population's divergence around twenty to thirty million years ago. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

was collect by Brad Maryan and Robert Browne-Cooper during April in 1992 at

Dirk Hartog Island A dirk is a long bladed thrusting dagger.Chisholm, Hugh (ed.), ''Dagger'', The Encyclopædia Britannica, 11th ed., Vol. VII, New York, NY: Cambridge University Press (1910), p. 729 Historically, it gained its name from the Highland Dirk (Scot ...

. '' Crenadactylus ocellatus'', found in a wider distribution of

Southwest Australia Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna. The region is also known as the Southwest Aus ...

, has also been referred to as the western clawless gecko. Prior to the revision in 2016, the population had been identified as two 'forms' found at adjacent ranges in the western regions of Australia and tentatively recognised as subspecies ''C. ocellatus ocellatus'' (southwestern clawless gecko) and ''C. ocellatus horni'' (central west coast clawless gecko).

Description

A species of ''Crenadactylus'', all of which differ in subtle details of their appearance but with deep divergence in the genome that indicates long periods of geographic isolation (20–30 mya). ''C. occidentalis'' has a relatively wide head and medium size, the snout vent length is recorded as 32.6 millimetres. The base colour over the body is tan and light brown. The striping common to the genus is distinctly contrasted, occasionally broken by spots where a few scales are yellow or white.

Distribution and habitat

Records of ''Crenadactylus occidentalis'' are at altitudes less than 100

metres asl Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

. The distribution range of the species is restricted to sub-coastal and coastal habitat in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to ...

, from Carnarvon to the south beyond the Northwest Cape to Yardie Creek. The range includes offshore areas near Carnarvon and at

Shark Bay Shark Bay ( Malgana: ''Gathaagudu'', "two waters") is a World Heritage Site in the Gascoyne region of Western Australia. The http://www.environment.gov.au/heritage/places/world/shark-bay area is located approximately north of Perth, on the ...

on Dorre and

Bernier Bernier is a French surname. Notable people with the surname include: * Chantal Bernier, Canadian lawyer * Charles A. Bernier (1890–1963), American college sports coach * David Bernier or Kike Bernier, Puerto Rican fencer * Étienne-Alexandre ...

s. The vegetation type of their habitat is composed of grass mounds of spinifex country and low coastal shrub-lands, dominated by banksia and acacia species. ''C. occidentalis'' has been located in

waste Waste (or wastes) are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor economic value. A waste pr ...

piles associated with recent human habitation of the rural region.

Conservation status

The IUCN has classified the species as

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. Th ...

and notes the species is located within at least one conservation zone of an extensive area of coastline. No specific conservation plan has assessed and evaluated threatening factors to the population, although the species is recognised for the purposes of conservation assessment. The quality and area of extent is noted as declining. ''Crenadactylus occidentalis'' is thought to be uncommon, although the lack of specific research, surveys and former position as a hidden species within ''Crenadactylus'' leaves some uncertainty about its population structure.

References

{{Taxonbar, from=Q63226175 Crenadactylus Reptiles described in 2016 Taxa named by Paul Doughty Taxa named by Ryan J. Ellis Taxa named by Paul M. Oliver Reptiles of Western Australia