New species of lizards from Auyantepui and la escalera in the Venezuelan Guayana, with notes on 'microteiid' hemipenes (Squamata: Gymnophthalmidae)

摘要

Names are provided for two montane gymnophthalmid lizards that have been long known from the Venezuelan Guayana, but that were not described by other workers because specimens had been lost. Euspondylus auyanensis, new species (5 Anadia sp. auctorum), is known only from the summit of Auyantepui, where it was originally discovered by S. Gorzula in 1984; a later specimen, the holotype, was collected by Renaud Boistel in 1998. The monophyly of Euspondylus has not been established and the generic assignment is tentative. Anadia escalerae, new species, is based on a specimen obtained by John Cadle in 1980, in the region of La Escalera, to the east of Auyantepui. It agrees with Anadia sensu stricto in being a slender attenuate lizard, but is unusual in having weakly keeled (vs. smooth) dorsal scales and in having the prefrontals separated by an azygous scale. The last condition also occurs in the holotype of A. pariaensis from the Península de Paria, about 500 km NNW of La Escalera; although differing in several characters, they may be sister species. A new specimen of the rare Anadia blakei (from Cerro Humo, Península de Paria), is described and illustrated. It is a robust lizard, markedly different in habitus from Anadia sensu stricto. Commentary is provided on the usefulness of hemipenial data in gymnophthalmid systematics. The hemipenes of Euspondylus auyanensis, Anadia blakei, and A. ocellata are described and illustrated. The Guayana endemic genus Adercosaurus is provisionally assigned to the subfamily Alopoglossinae based on hemipenial and other resemblances to Ptychoglossus.