On the Cranial Osteology of Eremiascincus, and Its Use for Identification.

摘要

A persistent problem for Australian paleontology has been a lack of diagnostic characters for identifying lizard fossils. Eremiascincus is one of the most widespread genera in Australia, so it was examined for distinguishing features and how it fits into a model of skink evolution. Skulls of Eremiascincus were examined within five separate contexts: 1) a description of the cranial osteology, 2) a qualitative comparison of individual cranial elements of Eremiascincus to closely related Ctenotus, 3) a description of the cranial allometry in Eremiascincus using linear morphometrics, 4) using cranial morphometrics of skinks to deduce their phylogeny, and 5) using geometric morphometrics to distinguish between individual elements of Eremiascincus and Ctenotus. Although linear morphometrics is adept at describing allometric changes to the skull during ontogeny, it only displayed a phylogenetic signal for small, closely related groups. Also, geometric morphometrics was just as capable distinguishing Eremiascincus from Ctenotus as qualitative characters.