Temporal Bones of the Gekkota Support Molecular Relationships within the Pygopodoidea

Abstract

Abstract Although molecular phylogenetic studies strongly support the monophyly of the Pygopodoidea, which comprise the gekkotan families Diplodactylidae, Carphodactylidae, and Pygopodidae, relationships among these constituent families are less robust. Morphological evidence for a particular three-taxon statement of pygopodoid relationships is hindered by the highly derived postcranial and trophic anatomy of limbless pygopodids relative to limbed gekkotans. We discuss variation in the temporal region of the gekkotan skull and identify a posteriorly dilated squamosal bone with a medially directed process, a character that is shared uniquely within Gekkota and more broadly within extant Squamata, by carphodactylids and pygopodids. The pygopodoid relationships (Diplodactylidae [Carphodactylidae, Pygopodidae]) implied by squamosal morphology are consistent with those receiving the greatest support from the most complete nuclear gene phylogenies.