Eothoracosaurus

Eothoracosaurus Temporal range: Late Cretaceous
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauria
Clade:	Pseudosuchia
Clade:	Crocodylomorpha
Clade:	Crocodyliformes
Clade:	Eusuchia
Genus:	†Eothoracosaurus Brochu 2004
Type species
Eothoracosuchus mississippiensis Brochu 2004

Eothoracosaurus is an extinct genus of eusuchian crocodylomorph which existed during the Late Cretaceous and early Paleocene. The animal is usually regarded as a gavialoid crocodilian, though the phylogenetic study published by Lee & Yates (2018) indicated that it was more likely to be a non-crocodilian eusuchian. If the animal was a gavialoid, it was one of the earliest and most basal gavialoids known.

Fossils are present from the Ripley Formation in Mississippi and date back to the early Maastrichtian stage of the Late Cretaceous. Some fragmentary material from the Coon Creek Formation of western Tennessee dating back to the late Campanian (slightly older than the specimens from Mississippi) has been referred to Eothoracosaurus as well. The Coon Creek Formation seems to have been deposited in a marine setting, with oceanic fauna such as the sharks Otodus and Squalicorax, the sea turtle Toxochelys, and mosasaurs including Plioplatecarpus and Globidens present from these strata. This suggests that Eothoracosaurus may also have led a marine lifestyle. Certain aspects of the cranial morphology of known specimens, such as a long anterior frontal process and widely spaced supratemporal fenestrae, distinguish it from the closely related Thoracosaurus neocesariensis from the late Maastrichtian and early Paleocene of New Jersey.