Cranial osteology of Moloch horridus (Reptilia: Squamata: Agamidae)

WA Museum Records and Supplements | Updated 7 years ago

ABSTRACT – We provide a detailed description of the cranial and mandibular osteology of the Australian agamid lizard, Moloch horridus, based on a series of eight skeletal preparations and minimal preparation of a single specimen preserved in alcohol. Articulated and disarticulated material permits the description of individual elements and their articulations, and a preliminary assessment of patterns of cranial and mandibular variation within Moloch. Preliminary comparisons of osteological features of Moloch with those of other Australian agamids indicate that many elements of the skull and mandible of Moloch have specialized morphology. Basic knowledge of patterns of skeletal variation within and among Australian agamids is insufficiently established at present to permit reliable hypotheses of phylogenetic relationships based only on morphology. A paucity of adequate skeletal collections exacerbates the challenges of elucidating patterns of evolutionary morphology for the group as a whole. Nevertheless, our preliminary assessment suggests that at least the maxilla, parietal, pterygoid, supraoccipital, prootic, otooccipital, basioccipital, dentary, coronoid, and articular-prearticular of Moloch can be clearly distinguished from those of other Australian agamids, and probably can be used to develop a reliable and more comprehensive skeletal morphological diagnosis for Moloch.

ADDITIONAL KEYWORDS: Skull, morphology, variation, thorny devil