Data from: Estimating cranial musculoskeletal constraints in theropod dinosaurs

Many inferences on the biology, behaviour and ecology of extinct
vertebrates are based on the reconstruction of the musculature and rely
considerably on its accuracy. Although the advent of digital
reconstruction techniques has facilitated the creation and testing of
musculoskeletal hypotheses in recent years, muscle strain capabilities
have rarely been considered. Here, a digital modelling approach using the
freely available visualization and animation software BLENDER is applied
to estimate cranial muscle length changes and optimal and maximal possible
gape in different theropod dinosaurs. Models of living archosaur taxa
(Alligator mississippiensis, Buteo buteo) were used in an extant
phylogenetically bracketed framework to validate the method. Results of
this study demonstrate that Tyrannosaurus rex, Allosaurus fragilis and
Erlikosaurus andrewsi show distinct differences in the recruitment of the
jaw adductor musculature and resulting gape, confirming previous dietary
and ecological assumptions. While the carnivorous taxa T. rex and Allo.
fragilis were capable of a wide gape and sustained muscle force, the
herbivorous therizinosaurian E. andrewsi was constrained to small gape
angles.