Phylogenetic relationships of the snake genus Conopsis based on morphology

Abstract

The snake genus Conopsis is endemic to Mexico and is found from Chihuahua to Oaxaca. It has been subject of study on its taxonomy due to recent modifications on its nomenclature. Now, this burrowing snake genus is diagnosed by several characters, standing out a groove in at least 1 of the 3-rear maxillary teeth. It comprises 6 known species: Conopsis acuta, Conopsis amphisticha, Conopsis biserialis, Conopsis lineata, Conopsis megalodon and Conopsis nasus. Previous works using morphological characters tried to solve the phylogenetic relationships between species in the genus but failed due to polymorphisms found in almost all characters studied. In this work those morphological characters were reevaluated using the generalized frequencies method and the relationships were recovered using the program Fastmorpholgy. Results show that C. nasus and C. megalodon are sister taxa and group together with C. amphisticha and C. biserialis. C. acuta remains as a basal species. Relationships within the external groups were partially resolved, but the Sonorini are not supported.