Meeting Abstract
Crocodylomorph taxa are represented today by members of the crown clade Crocodylia, adults of which typically have exceptional bite forces, bone-crushing teeth, and robust—if elongate—jaws. These features allow mature individuals to be particularly adept at capturing and subduing large, elusive prey. Neonatal forms, on the other hand, hatch with unremarkable bite-force capacities, delicate dentitions, and unusually short snouts for jaw prehension but reach the adult configuration within a few years of growth. These developmental patterns appear to broadly mirror the increasing size and robustness of the crocodylomorph jaw system during its 230 million year diversification. Such evolutionary shifts are presumed to relate to changes in the feeding biology of these animals at cladogenic events, analogous to feeding niche shifts undertaken by their modern counterparts during ontogeny. To formally investigate this relationship, I identified functionally important aspects of the crocodylomorph feeding system through ontogenetic bite-force experimentation, musculoskeletal modeling, examination of fossil material, and drawing from the literature to correlate developmental and evolutionary character changes in the feeding apparatus. I tested the hypothesis that shifts in the cranial osteology of fossil crocodylomorphs match those documented during the ontogeny of their living descendants. Results demonstrated functional similarities between basal crocodylomorph adults and modern crocodylian hatchlings, whose evolutionary and developmental histories indicate comparable modifications for augmenting maximum bite forces and increasing skull strength. These findings suggest developmental and evolutionary conservation of the jaw system and point towards potentially long-standing constraints on the embryonic craniofacial bau plan of crocodylomorphs that are released post hatching via strongly allometric growth.
