In this study the author analyzes the phylogenetic relationships among the genera and species of alligator lizards (Squamata: Anguidae: Gerrhonotinae).
The subfamily consists of six monophyletic genera: Coloptychon, Gerrhonotus, Elgaria, Barisia, Mesaspis, and Abronia.
The author reviews the history of gerrhonotine taxonomy, provides a key to, and diagnoses of, all gerrhonotine taxa, and discusses taxonomic and biogeographic implications of gerrhonotine relationships.