New York, N.Y. : American Museum of Natural History
Abstract
20 p. : ill., map ; 26 cm.Includes bibliographical references (p. 19-20)."Rhadinophanes, new genus, is erected for a small colubrid snake from high montane forest (~2750 m.) on Cerro Te贸tepec, in the Sierra Madre del Sur of central Guerrero, Mexico. The characteristics of Rhadinophanes monticola, new species, include a mottled linear pattern, enlarged, ungrooved rear maxillary teeth, and smooth dorsal scales with paired apical pits, in 19-19-17 rows. The hemipenis has a centripetal sulcus spermaticus and is distinctly bilobed, with each lobe being spinose basally and individually calyculate and capitate distally. Rhadinophanes monticola resembles snakes of the genera Rhadinaea and Coniophanes, but it is comparatively primitive in hemipenial structure and in several other relevant characters. Although Rhadinophanes might represent the plesiomorphic sister group of Rhadinaea and Coniophanes, the monophyly of these phenotypically similar snakes could not be demonstrated. In contrast, a sister-group relationship is corroborated for Rhadinophanes and the very dissimilar Tantalophis, on the basis of unusual hemipenial features judged to be synapomorphies. The phyletic position of Rhadinophanes and Tantalophis to other genera is uncertain, although similarity can be found to such diverse groups as Rhadinaea-Coniophanes and Leptodeira-Cryophis of Middle America, and with various alsophiine colubrids, which occur widely in the American mainland, West Indies, and Galapagos. The hemipenes of Rhadinophanes and Tantalophis are reminiscent of the alsophiine type, although there seems to be fundamental disparity in several characters, including the synapomorphic features that affirm the monophyly of these two otherwise divergent genera"--P. [1]
