Reptiles exhibit marked diversity in sex-determining mechanisms. Many species exhibit
genotypic sex determination (GSD) with male heterogamety (XX females/XY males), others
have GSD with female heterogamety (ZW females/ZZ males), and still others exhibit
temperature-dependent sex determination (TSD). The distribution of these mechanisms
throughout the reptile phylogeny implies evolutionary lability in sex determination, and in
some lineages there has been a number of transitions between GSD and TSD. Despite this …