Figure 2. Phylogenetic relationships and numbers of species of the sceloporine genera. Phylogeny based on Presch (1969: 286), after Etheridge (1964). Primitive character states designated by capital letters. Small letters indicate derived character states. Species numbers are from Smith and Taylor (1950). By 1966 taxonomic revisions changed Holbrookia to 3 species, Petrosaurus to 3, Phrynosoma to 14, and Sceloporus to 57.