Ontogenetic changes in jaw-muscle architecture facilitate durophagy in the turtle Sternotherus minor

摘要: Differential scaling of musculoskeletal traits leads to differences in performance across ontogeny and ultimately determines patterns resource use during development. Because growth the feeding system facilitates high bite-force generation necessary overcome physical constraints consuming more durable prey, durophagous taxa are well suited for investigations relationships between growth, dietary ontogeny. To elucidate which biomechanical factors responsible allometric changes bite force durophagy, we developed experimentally tested a static model throughout development turtle Sternotherus minor . Moreover, quantified fracture properties snails found diet evaluate relationship forces required process prey. We that (1) accurately predicts ontogenetic forces, (2) positive allometry is accomplished by augmenting muscle size pennation, (3) rupture show similar pattern These results indicate importance pennation generating while maintaining provide empirical evidence S. strongly linked structural their primary prey. * M. add. mand. : Musculus adductor mandibulae post. posterior pseudo. pseudotemporalis ptery. pterygoideus P. prof. α Pars profunda β γ sup. superficialis PCSA physiological cross-sectional area SL skull length θ angle BF force BFmed generated media BFpost BFpseudo,ptery pseudotemporalis BFsup,pro superficialis (α, β, γ) F med post pseudo,ptery M.pterygoideus sup,pro IL in-lever ILmed length ILpost ILpseudo,ptery ILsup,pro J jaw joint MA mechanical advantage (RIL:OL) OL out-lever RBF right-side RIL resolved regression intercept b slope (scaling coefficient) CI confidence interval r 2 coefficient determination RMA reduced major-axis regression significance level ARF average five largest each turtle I isometry N negative allometry OpL snail operculum P SnL