Herpetofauna of the Yutajé-Corocoro massif, Venezuela : second report from the Robert G. Goelet American Museum-Terramar Expedition to the northwestern tepuis. Bulletin of the AMNH ; no. 261

The Yutajé-Corocoro massif is a highly eroded sandstone table mountain, with internal drainage mainly to the central valley of the Río Corocoro, a stream in the headwater drainage of the Río Manapiare--some 100 km east of the middle Río Orinoco, at the northern edge of the State of Amazonas in southern Venezuela. The rocky soil supports a mosaic of diverse scrubland and forest, with small tepui meadows at the higher elevations. The herpetofauna is depauperate, as is typical of the Venezuelan tepuis. Eight species of amphibians and reptiles were collected during a 7-day period in the dry season (February). This sample includes two new frogs (Hyalinobatrachium eccentricum, n. sp., Centrolenidae; Colostethus undulatus, n. sp., Dendrobatidae) and a new genus and species of lizards (Adercosaurus vixadnexus, n. gen. & sp., Teiidae), all of which were found in humid montane mossy forest at 1700-1750 m elevation. Another new lizard (Tropidurus panstictus, n. sp., Tropiduridae) was discovered at lower elevations (180-1220 m), especially in dry scrub. The fauna also includes a widespread lowland frog (Pseudopaludicola llanera Lynch), two tepui frogs (Eleutherodactylus cantitans Myers and Donnelly; E. yaviensis Myers and Donnelly), a tepui lizard (Prionodactylus goeleti (Myers and Donnelly), new combination), a snake (Liophis?) that escaped capture, and another snake (Thamnodynastes corocoroensis Gorzula and Ayarzagüena) obtained by S. Gorzula in 1987. The two Eleutherodactylus and the Prionodactylus also occur on neighboring Cerro Yaví (the type locality), although one of the frogs (E. yaviensis) and the lizard show evidence of differentiation. Based on the original description, the snake Thamnodynastes corocoroensis appears to be distinct from a related species on Cerro Yaví. Two of the new species exhibit characters that are novel or not previously noted. The dendrobatid frog Colostethus undulatus, n. sp. has a glandular supracarpal pad atop the wrist, being best developed in males. This species, which also has the parasphenoid bone curiously concealed, seems to be unusual among tepui Colostethus in lacking the recently described median lingual process. The centrolenid frog Hyalinobatrachium eccentricum, n. sp. has a peculiar bicolored iris, with a dark median sector that conceals the pupil and which apparently dilates with the pupil. This character is retained in preservative and differentiates H. eccentricum from H. crurifasciatum Donnelly and Myers. Both species share a previously overlooked bubblelike structure in the web between the third and fourth fingers, herein termed bulla (possibly parasite induced?).
85 p. : ill. (some col.) ; 26 cm.
Includes bibliographical references (p. 82-85).