Aspidoscelis Fitzinger

Castiglia, Riccardo, Annesi, Flavia, Bezerra, Alexandra M. R., García, Andrés & Flores-Villela, Oscar, 2010, Cytotaxonomy and DNA taxonomy of lizards (Squamata, Sauria) from a tropical dry forest in the Chamela-Cuixmala Biosphere Reserve on the coast of Jalisco, Mexico, Zootaxa 2508, pp. 1-29 : 23

Genus Aspidoscelis Fitzinger

Species of the genus Aspidoscelis were previously included in Cnemidophorus , but based upon divergent morphological, molecular and enzymatic characters the two genera were recognized as separate ( Reeder et al. 2002). Thus, Aspidoscelis is resurrected for the North American ‘‘ Cnemidophorus ’’ clade containing 87 species included in the deppei , sexlineata, and tigris species groups (and the unisexual taxa associated with them). Aspidoscelis occurs throughout most of North America (except Canada), reaching the East and West Coasts of the United States, and ranging south through all Mexico and into Central America. The species groups differ also for their karyotypes. A 2n = 52 is observed in the deppei group, a 2n = 46 in the sexlineata group and a 2n = 46 with XY sex chromosomal system in the tigris group. Lowe et al. (1970) suggested a chromosomal evolution pattern through a reduction of the diploid number. This view has been slightly modified by Reeder et al. (2002), who considered that the ancestor probably had a karyotype of 2n = 50.