FEEDING BIOMECHANICS INFLUENCES CRANIOFACIAL MORPHOLOGY AMONG EAST AUSTRALIAN PADEMELONS (MACROPODIDAE: THYLOGALE)

Interspecific variation in the craniofacial morphology of extant macropods is associated with the mechanical properties of preferred vegetation types and the cropping behaviours used to access them. We employed a combination of established morphometric analyses and novel finite element approaches to examine whether these associations also persist at finer taxonomic scales. Three closely-related pademelon taxa were examined, all of which have distinct proportions of graze and browse in their diets: the red-necked pademelon (Thylogale thetis), and two sub- species of the red-legged pademelon (Thylogale stigmatica stigmatica and Thylogale stigmatica wilcoxi). We identified clear morphological differences in cranial shape and biomechanical performance that are consistent with the respective feeding regimes of each taxon. We also identified significant influences of geography and climate on cranial shape that correspond with the latitudinal differences in the properties of vegetation. Together, our findings suggest that feeding ecology plays an important role in determining craniofacial morphology down to the sub-species scale among macropods. This lends further support to a clear relationship between feeding biomechanics and cranial morphology across the Macropodidae, and to the predictive power of inferring ecology from morphology for species conservation and management.