Ontogenetic scaling of cranial morphology and bite-force generation in the loggerhead musk turtle

摘要: The feeding systems of durophagous vertebrates are well suited for studying how the performance structures is affected by growth. For these animals, that deviate from isometric growth (i.e. allometry) may be biologically meaningful in terms disproportionate increases bite-force generation across ontogeny. We measured body size, cranial morphology and an ontogenetic series loggerhead musk turtles Sternotherus minor compared scaling coefficients with predictions based on isometry. found morphological S. characterized positive allometry dimensions head beak (rhamphotheca) relative to size. Because negative or isometry size a nearly universal trait among vertebrates, appears unique this regard. In addition, we bite forces scaled all measurements. These results suggest modified lever mechanics, and/or increased physiological cross-sectional area through changes muscle architecture fiber lengths, degree pennation) jaw adductor musculature have more explanatory power than external measures taxon. Lastly, force lower depth symphyseal length, indicating development high requires disproportionately robust mandible. indicate deviations make it possible generate, transfer dissipate mechanical during