Data for: A short-snouted "sphenosuchian” with unusual feeding anatomy demonstrates that ecological specialization occurred early in crocodylomorph evolution

The early evolution and diversification of Crocodylomorpha is a key
component of vertebrate evolution on land but is somewhat poorly
understood as a result of limited data. We describe Eosphorosuchus
lacrimosa gen. et sp. nov., an early crocodylomorph from the Late Triassic
of Ghost Ranch, New Mexico, whose cranial anatomy is divergent from that
of other early crocodylomorphs (including Hesperosuchus agilis, to which
it had been tentatively assigned), featuring an unusually short and
osteologically reinforced facial region. A robust upper temporal arch and
prominent surangular ridge indicate the presence of well-developed
superficial external adductor musculature, which is divergent relative to
pseudosuchians generally. These autapomorphies suggest specialization for
a powerful bite. Bayesian and maximum parsimony phylogenetic analyses find
E. lacrimosa outside of an H. agilis clade, near the base of
Crocodylomorpha. The specializations of E. lacrimosa therefore represent
the beginnings of ecological diversification within Crocodylomorpha among
animals of a similar size, predating the Late Triassic appearance of
Crocodyliformes and the Jurassic radiation of mesoeucrocodylians.
Coexistence in the same single-event death assemblage of E. lacrimosa and
H. agilis—two small-bodied early crocodylomorphs with functionally
significant anatomical differences—suggests partitioning of terrestrial
carnivorous niches within the “sphenosuchian” grade.