Feeding capabilities of thalattosuchians through the lens of biting performance

Thalattosuchia is an extinct group of aquatic crocodylomorphs globally distributed from the Early Jurassic to the Early Cretaceous. Most species possessed elongated snouts capable of delivering a rapid bite, comparable to those of extant longirostrine crocodilians. However, some lineages evolved more robust skulls and dentition, interpreted as hypercarnivorous such as Dakosaurus. While several studies have investigated the biomechanics of thalattosuchian crania, few have focused on mandibular biomechanical performance. Here, we compared biting performance in numerous thalattosuchians and
extant crocodilians using high-definition 3D models. This study aims to quantify thalattosuchian feeding capabilities using realistic bite simulations, performed via muscle-driven finite element analyses (FEA). Muscle attachment sites were mapped on the skull and mandibles to reconstruct three-dimensionally the jaw adductor musculature and estimate muscle forces. Biting simulations were performed considering a bilateral bite at mid-dentigerous length with a 10° gape angle. In parallel, an artificial intramandibular fenestra was added to metriorhynchids to determine whether the loss of this feature
benefited biting performance. Our results reveal a diversity in biting performance across Thalattosuchia. Elevated internal energy values in teleosauroids and basal metriorhynchoids suggest that maximal muscle force was not recruited during biting, pointing toward a predatory strategy suited to small, soft prey items. In contrast, extant longirostrine crocodilians exhibit significantly lower internal energy values despite similar bite forces. Derived, unrelated taxa such as Machimosaurus and Dakosaurus evolved
jaws generating powerful bites with high mechanical efficiency, while differences in stress patterns suggest distinct feeding niches. Our findings offer practical insights into the feeding habits of thalattosuchians and biomechanical constraints that characterized their evolution.