Data from: Convergence and functional evolution of longirostry in crocodylomorphs

During the Mesozoic, Crocodylomorpha had a much higher taxonomic and
morphological diversity than today. Members of one particularly successful
clade, Thalattosuchia, are well-known for being longirostrine: having
long, slender snouts. It has generally been assumed that Thalattosuchia
owed their success in part to the evolution of longirostry, leading to a
feeding ecology similar to that of the living Indian gharial, Gavialis.
Here, we compare form and function of the skulls of the thalattosuchian
Pelagosaurus and Gavialis using digital reconstructions of the skull
musculoskeletal anatomy and finite element models to show that they had
different jaw muscle arrangements and biomechanical behaviour.
Additionally, the relevance of feeding-related mandibular traits linked to
longirostry in the radiation of crocodylomorph clades was investigated by
conducting an evolutionary rates analysis under the variable rates model.
We find that, even though Pelagosaurus and Gavialis share similar patterns
of stress distribution in their skulls, the former had lower mechanical
resistance. This suggests that compared to Gavialis, Pelagosaurus was
unable to process large, mechanically less tractable prey, instead
operating as a specialised piscivore that fed on softer and smaller prey.
Secondly, innovation of feeding strategies was achieved by rate
acceleration of functional characters of the mandible, a key mechanism for
the diversification of certain clades like thalattosuchians and
eusuchians. Different rates of functional evolution suggest divergent
diversification dynamics between teleosaurids and metriorhynchids in the
Jurassic.