PHYLOGENETIC RELATIONSHIPS OF EMYDINE TURTLES

Abstract

We studied the phylogeny, taxonomy, and historical ecology of emydine turtles (genera Clemmys, Emydoidea, Emys, and Terrapene) using a wide range of behavioral, morpho- logical, life history, and ribosomal DNA characters. Results of parsimony analyses of the 77 infor- mative characters yielded two minimum length trees, differing within Terrapene but agreeing with the hypothesis: ((((C. insculpta, C. muhlenbergii) C. guttata) C. marmorata) (Emys, Emy- doidea) Terrapene). This result suggests that, contrary to a recent analysis of the rDNA data alone, Emys, Emydoidea, and Terrapene form a monophyletic clade, and also, contrary to most previous hypotheses, Clemmys is paraphyletic. These results have implications for studies of the evolution of the mode of sex determination, terrestriality, and mechanisms of plastal closing in this group.