Taxonomic revision of the tribe Dipsadini (Serpentes: Dipsadidae: Dipsadinae)

Abstract

The Dipsadini, a tribe of dipsadine colubrids, comprises the genus Dipsas, Plesiodipsas, Sibon, Sibynomorphus and Tropidodipsas, with 66 valid species of neotropical snakes, distributed from Mexico to northern Argentina. These genera show an extensive variation on color patterns and pholidosis, characters upon which relies the group systematic. Although several taxonomic works has been published on some species and species groupings within the recognized genera, the taxonomy of the Dipsadini still remain unstable, due, mainly, to the high variability found in most morphological characters used on the taxonomy of the group, making difficult the delimitation of the genera and its species. Confronting these limits, is essential an exhaustive review, including available specimens of all the currently recognized species of the five Dipsadini genera, to generate a more comprehensive understanding of this group.The objective of this effort is to generate a taxonomical revision of Dipsadini by the analysis of the morphological and geographic variation of the recognized species of Dipsas, Plesiodipsas, Sibon, Sibynomorphus e Tropidodipsas, providing a morphologically-based delimitation of these genera using pholidosis, biometry, coloration patterns and cranial and hemipenial morphology of all the currently recognized taxa of the tribe. Afterwards, is expected to generate useful information for further phylogenetic approaches, aiming to test the monophyly of the Dipsadini, to delimitate its natural groups and to clarify its position within the Dipsadinae (AU)