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Dryad

Data from: Divergent feeding biomechanics in Late Cretaceous marine reptiles from the Western Interior Seaway

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Mar 31, 2026 version files 141.08 KB

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Abstract

Sympatry of numerous predatory marine reptiles appears to be the rule rather than the exception in many Mesozoic formations, implying that these lineages likely evolved some form of ecological partitioning. Many studies have focused on dental morphology as a proxy for the feeding habits of aquatic tetrapods, but much more ecological insight may be gained through simulations of the mechanical performance of craniomandibular elements. Here, we conducted the first, large-scale, comparative study of marine reptile jaw biomechanics, applying muscle-driven finite element analyses (FEA) on a dataset of high-resolution three-dimensional models. Our study-system included mosasaurids and polycotylid plesiosaurians from the Santonian-Maastrichtian of the Western Interior Seaway (WIS), a vast inland sea that stretched longitudinally across North America during the Late Cretaceous. Muscle insertions were identified to reconstruct jaw adductor muscles and simulate respective muscle and bite forces. We simulated realistic muscle traction dynamics during biting, including simulations at multiple opening angles and bite locations. We recover clearly distinct biomechanical performances among the sample, notably between the slender-snouted mosasaurids (e.g. Clidastes) plus polycotylids, and the robust-jawed mosasaurids (e.g. Prognathodon). By integrating jaw size, mechanical efficiency, and internal energy, we provide strong support for differential biting mechanics among these marine predators, which doubtless influenced their ecological role. Our results offer deeper insight into feeding ecologies in Late Cretaceous marine reptiles and provide a unified protocol to assess the role of feeding biomechanics in niche partitioning among sympatric marine reptiles from well-sampled regions.