Saturday, September 3, 2011

Western Australia's New Gecko in the Genus Underwoodsaurus

More than 40 species of geckos in four families inhabit western Australia's Pilbara. Three species of carphodactylid geckos are known in the Pilbara by three species in two genera (Nephrurus and Underwoodsaurus).The Pilbara Nephrurus include two relatively common and widespread endemic subspecies; N. levis pilbarensis and N. wheeleri cinctus. Underwoodisaurus is much rarer, and known from relatively few specimens and scattered observational records An undescribed Underwoodisaurus was first collected in 1997, but lack of further specimens prevented a proper assessment of its taxonomic distinctiveness. Bought and Oliver (2011) now report on recent collections and photographic records which provided sufficient material for a comparison with U. milii, the other Pilbara Underwoodsaurus, and evidence to warrant its formal description as a new species. The describe Underwoodisaurus seorsus, a new species similar to U. milii, but differing in its plain dorsal and head patterns; sparsely scattered pale tubercles; more gracile build; longer snout, limbs and digits; smaller and more numerous fine scales on the dorsum, and the enlarged tubercles on the tail tending not to form transverse rows. Underwoodisaurus seorsus is known from few specimens and has only been encountered at mid elevations in the Hamersley Ranges, widely separated from the closest populations of U. milii in the northern Goldfields and Shark Bay in Western Australia. U. seorsus has only been collected from rocky areas, and U. milii are frequently associated with rocks. The distribution of U. seorsus and U. milii suggests that their common ancestor was once more widely distributed, but aridification and increasing temperatures eliminated populations in the Gascoyne region. The rocky gorges and moderately high elevations of the southern Pilbara ranges may have acted as a relatively moist and potentially cooler refugium, allowing an isolated population of Underwoodisaurus to persist at mid elevations. Given its rarity and small distribution it may be in need of protection.

Citation
Doughty P. and P. M. Oliver. 2011.A new species of Underwoodisaurus (Squamata: Gekkota: Carphodactylidae) from the Pilbara region of Western Australia. Zootaxa 3002: 20–30.

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