A preliminary analyze of cranial variations in three Amphisbaenia species

HOHL; LEANDRO; AZORIT, CONCEPCIÓN; ROCHA BARBOSA, OSCAR; VASSALLO, ALDO; CASINOS, ADRIÀ

Cairns

Congreso; International Congress Vertebrate Morphology 2023; 2023

Internacional Society Vertebrate Morphology

Amphisbaenia is a fossorial group of Reptiles. They display morphological adaptations toburrowing, namelly, a cylindrical and elongated body, a tendency to lack legs, and a stronglyossified and compacted skull. Regarding the skull four morphotypes can be assumed: roundheaded,spade-headed, keel-headed, and shovel -headed, beeing the snout region the main cranialvariation. The intermediate region of the skull and the occipital zone are more constant in thedifferent species of the group. However, it is worth mentioning that these skull regions areparticularlly related to many aspects of their life, such as excavation activity and related biteforce, for example. We hypothesize that there are significant variations in these skull regionsbetween different species and that such variations may be related to their lifestyles. The mainobjective of our research was to analyze, in a preliminary way, cranial variations between threespecies of Amphisbaenia nameli, Amphisbaena darwinii, Blanus cinereus (both with a roundedskull), and Leposternon microcephalum (with a snout-headed skull). For this, computerizedmicrotomography of four adult specimens of each species were analyzed using 3D GeometricMorphometrics, based on 22 landmarks describing the intermediate and occipital skull regions.Associated Principal Component Analyzes showed a clear difference between the three speciesstudied.