Pachydactylus is a genus of insectivorous geckos, lizards in the family Gekkonidae. The genus is endemic to Africa, and member species are commonly known as thick-toed geckos. The genus also displays rich speciation, having 58 distinct species identified when compared to other closely related gecko genera like Rhoptropus, most of which have emerged since 35Ma.[1] It has been suggested that the reason for this rich speciation not from adaptive radiation nor nonadaptive radiation, but that the genus represents a clade somewhere between the two drivers of speciation.[2] P. bibronii geckos have been used by NASA as animal models for experimentation.[3]
The genus Pachydactylus is characterized by dilated toe tips, usually with undivided scansors. Body scales are small, granular and non-overlapping, with scattered, large keeled tubercles.
Coloration of Pachydactylus species varies, but is generally drab in color.
Presence of adhesive toe pads varies by species and habitat, with rock dwelling species of Pachydactylus retaining adhesive pads, but unambiguous independent loss of toe pads in sand dwelling and burrowing species like P. rangei.
Body size in Pachydactylus varies across the 58 species, ranging from 35 to 115mm Snout-Vent Length (SVL)[4] with the ancestral condition of a larger body size with adhesive toe pads to suit a generalist habitat.
All observed species of Pachydactylus are strictly nocturnal. Wikibooks
sp. geckosPachydactylus species live in a diverse range of habitats across Southern Africa. Habitat varies by species, with some species preferring generalist habitats, human dwellings, rock-dwellings, and sand dwellings. Habitat preference typically varies by body size and retention of toe pads, which varies across the genus. The body size of Pachydactylus geckos has been shown to correlate with their habitat range.[5]
Lizards of the genus Pachydactylus feed mainly on arthropods, but have been observed eating small vertebrates.[6]
The geographic range of the genus Pachydactylus is centered on Southern Africa, with some species reaching East Africa, the northernmost limit of their distribution. In South Africa's rugged Richtersveld region, Pachydactylus geckos comprised 13 of 18 all gecko species surveyed.[7]
There are 58 species that are recognized as being valid:[8]
A binomial authority in parentheses indicates that the species was originally described in a genus other than Pachydactylus.
fr:Aaron Matthew Bauer
.fr: William Roy Branch
. A revision of the Pachydactylus serval and P. weberi groups (Reptilia: Gekkota: Gekkonidae) of Southern Africa, and with the description of eight new species. . Proceedings of the California Academy of Sciences . 2006 . 57 . 23 . 595–709 .fr:William Roy Branch
. 2004 . Field Guide to Snakes and other Reptiles of Southern Africa . Third Revised edition, Second impression . Sanibel Island, Florida . Ralph Curtis Books . 399 . 0-88359-042-5 . (Genus Pachydactylus, pp. 249–250) .