Taxonomic review of the genus Apostolepis Cope, 1862 (Serpentes, Dipsadidae, Xenodontinae, Elapomorphini)

Apostolepis is the most diverse genus of the Tribe Elapomorphini. It is composed of 40 valid species, being 36 from Brazil and others distributed in the Guianas, Colombia, Peru, Bolivia, Paraguay and Argentina. The genus Apostolepis is recognized as one of the most problematically taxonomic groups of Dipsadidae because original species descriptions with insufficient information, sometimes based on intraspecific variations and anomalous specimens. More than 50 nominal taxa are related to Apostolepis, of which 21 were described in the last 30 years and 35 based only on the holotype; several taxa already synonimized to species described above. Because of life habits of species are not abundantly found, causing that many species are still minimally known and others known only by the holotype. Combining all these factors, many misunderstandings were generated in the identification of the species, contributing to a massive succession of taxonomic controversies and resulting in an unsatisfactory understanding of the evolution, ecology and natural history of the species. For these reasons, this study aimed to review the taxonomy of species currently allocated to the genus, examining series of European, South and North American museums through visits, loans and data sent by institutions. Of 1803 specimens from 32 scientific collections, referring to 50 nominal taxa I analyzed meristic characters, of small part I observed the hemipenian and cranial morphology, of about 817 specimens obtained data of coloration, folidosis and morphometry and from remainder were used only characteristics of the color pattern. These analyzes allowed the correct definition of the taxa, verification of their validity, identification of possibly new species and the geographical distribution of valid taxa. In addition to the description of the new species, the taxonomic changes proposed here are the revalidation of Apostolepis sanctaeritae, synonimized to A. cearensis; the synonymization of species A. ammodites (to A. sanctaeritae), A. barrioi (to A. dimidiata), A. cerradoensis (to A. albicollaris), A. multicincta (to Apostolepis dorbignyi), A. roncadori (to Apostolepis vittata), A. serrana (to A. striata), A. tertulianobeui (to A. assimilis), A. borellii and A. underwoodi (to A. nigroterminata); correction of the spelling of names A. ambinigra, A. arenaria and A. phillipsi and the name Apostolepis lineata suggested as nomen dubium. At the end of the revision we have 301 valid species of Apostolepis and some unsolved questions, such as the taxonomic definition of the Apostolepis longicaudata complex and the confirmation and description of two possible new species of the Cerrado and Cerrado-Amazonian ecotone. This study allows the valid species of Apostolepis to be recognized, allowing the establishment of terminal taxa for phylogenetic analysis, which will result in hypotheses about the origin, evolution and biogeography of species of the genus. (AU)