The phylogenetic relationships of the Central American snake Tretanorhinus: data from morphology and karyology

Abstract In spite of numerous references to Tretanorhinus as a natricine or natricid snake, significant characters of the dentition, vertebrae, hemipenis, and scutellation agree with previous immunological data which indicated that Tretanorhinus is a member of the Central American Dipsadidae. The karyotype of Tretanorhinus variabilis supports the view that this genus is not a natrid.