MYERS AND DONNELLY: AUYANTEPUI HERPETOFAUNA

摘要

Auyantepui is an immense sandstone table mountain in the Venezuelan Guayana. This mesadid not appear on aviation maps and was unknown to the literate world prior to the late 1930s.It was explored from the air by Jimmy Angel, a bush pilot and colorful soldier of fortune forwhom the world's highest waterfall is named (Angel Falls at the northern end of Auyantepui).About the same time, in 1937, Captain Felix Cardona Puig and Gustavo Heny discovered anaccess crack in the sandstone, allowing ascent onto the southern end of the mesa. The firstscientific exploration followed immediatelythe 1937-1938 Phelps Venezuelan Expedition ofthe American Museum of Natural History made the first zoological and general botanicalcollections. Today, no tepui other than the "Lost World" of Cerro Roraima is better known tothe general public. The summit of Auyantepui has a known fauna of 24 species of amphibians and reptiles,including species added by the Robert G. Goelet American Museum—TERRAMAR Expedition in1994. This expedition collected 16 species during a month of fieldwork in the dry season(February), in five camps at elevations of 1700-2100 m above sea level. All species known fromthe summit of Auyantepui are treated in this bulletin; illustrations where possible includetadpoles, bioacoustic spectrograms, and hemipenes. Four new species are describedtwo frogs (Hypsiboas angelicus, n. sp., Eleutherodactylusauricarens, n. sp.), a lizard (Arthrosaura montigena, n. sp.), and a snake (Atractus guerreroi, n. sp.). Arthrosaura montigena possesses a hemipenial character not previously describedanorifice (orificium) of unknown function, situated in the lobular crotch between the two lobes.Attention is called to a probably undescribed snake (Liophis "miliaris" sensu lato) from thenearby Gran Sabana. The herpetofauna of the Auyan summit comprises 12 families, 20 genera, and 24 species. Thisis compared with the known herpetofauna of the Chimanta massif, lying less than 50 km south-southeast of Auyantepui. Despite the proximity and similar dimensions, the summits ofAuyantepui and Chimanta have in common only 11% of the combined number of species (4 of36), 44% of the genera (11 of 25), and 62% of the families represented (8 of 13), showing thatneighboring tepuis may have herpetofaunas very different from one another. Nonetheless, theadjacent mountains that constitute the more fragmented Chimanta massif are relatively close toone another and seem to have a unified herpetofauna.