Butler's Burrowing Scorpion Urodacus butleri Volschenk, Harvey & Prendini, 2012

(after Volschenk et al. 2012): Urodacus butleri differs from all other Urodacus species, except U. manicatus, U. novaehollandiae and U. planimanus, on the basis of its extremely dark coloration. The carapace of U. butleri is smooth whereas that of U. manicatus is finely granular. Urodacus butleri can be distinguished from U. planimanus by the absence of prominent spiniform granules at the posterior ends of the dorso-submedian carinae on metasomal segments II–IV in the adult male. Prominent spiniform granules are evident in the male of U. planimanus. Urodacus butleri closely resembles U. novaehollandiae, some populations of which may be very dark in coloration. Urodacus butleri differs from U. novaehollandiae by the smooth carapace and dark coloration of the legs. The legs of U. novaehollandiae are typically much paler and contrast strikingly with the dark mesosoma. The pedipalp chelae of U. butleri and U. novaehollandiae are similar in proportions, differing from the chela of U. planimanus, which is more slender. Urodacus butleri differs further from U. novaehollandiae and U. planimanus in the proportions of metasoma IV, which is consistently shorter than U. planimanus and shallower than in U. novaehollandiae.

The holotype of U. butleri was collected on Barrow Island, but populations from the mainland Pilbara were recorded in the original description. Molecular data suggest that these may represent different species and we here only refer the Barrow Island populations to U. butleri. The species is therefore also diagnosed by molecular methods (COI barcoding).

• native

• Western Australia