The genus Dipsas includes approximately 32 species, distributed from Mexico to South America (Brazil, Argentina, Paraguay, Bolivia and Peru). High variability in color pattern and scalation has made it difficult to define limits among Dipsas species and to interpret patterns of geographic variation. We analyzed 14 meristic and 18 morphometric characters of 483 specimens of D. catesbyi and 129 specimens of D. pavonina, as well as their color pattern, coloration, hemipenis, cephalic glands and geographic distribution. We describe variation in meristic and morphometric characters and incorporate new characters into revised diagnoses. The results indicate a greater morphological similarity between D. catesbyi and species of Sibynomorphus than with the other species of Dipsas. More morphological studies should be done to evaluate current phylogenetic proposals for relationships within the tribe Dipsadini.
圖片連結: repti.net (photo credit: Björn Rogell) (下圖為Dipsas bicolor), herpetofauna.ex-br.com (photo credit: Paulo S. Bernarde), Calphotos (photo credit: Enrique Flores C.)