Morphological convergence and molecular divergence: The taxonomic status of Sceloporus serrifer (squamata, phrynosomatidae) subspecies

The systematics of the subspecies included in Sceloporus serrifer has undergone several taxonomic and nomenclatural rearrangements. This species previously comprised two recognized subspecies, Sceloporus serrifer serrifer and Sceloporus serrifer prezygus, which inhabit contrasting habitats. In this study, we re-evaluate the taxonomic status of both subspecies using molecular and morphological evidence. Sceloporus serrifer serrifer was recovered as a paraphyletic group, whereas S. s. prezygus was recovered as a polyphyletic group. The molecular results indicate the existence of two independent lineages that diverged at least 1.29Myr, with the populations currently recognized as S. s. prezygus from the Cuchumatanes Mountains representing a secondary invasion of S. s. serrifer from the lowlands. The lack of meristic differences among the highland populations of different species suggests convergence in similar environments achieved by two different lineages.