Eothoracosaurus is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of gavialoid

Gavialoidea

Gavialoidea is one of three superfamilies of crocodylians, the other two being Alligatoroidea and Crocodyloidea. Although many extinct species are known, only the gharial Gavialis gangeticus and possibly the False gharial Tomistoma schlegelii are alive today.-Classification:Gavialoidea contains the...

 crocodilia

Crocodilia

Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period . They are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria...

n. It was one of the earliest and most basal

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 gavialoids known. Fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s are present from the Ripley Formation

Ripley Formation

The Ripley Formation is a geological formation in North America found in the U.S. states of Alabama, Georgia, Mississippi, Missouri, and Tennessee. The lithology is quite consistent throughout the layer. It consists mainly of glauconitic sandstone. It was formed by sediments deposited during the...

 in Mississippi

Mississippi

Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...

, and date back to the early Maastrichtian

Maastrichtian

The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...

 stage of the Late Cretaceous

Late Cretaceous

The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...

. Some fragmentary material from the Coon Creek Formation

Coon Creek Formation

The Coon Creek Formation is a geologic formation located in western Tennessee and extreme northeast Mississippi. It is a sedimentary sandy marl deposit, Late Cretaceous in age, about 70 million years old. The formation is known for producing mosasaurs and plesiosaurs, particularly at Coon Creek in...

 of western Tennessee

Tennessee

Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...

 dating back to the late Campanian

Campanian

The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...

 (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 shark

Shark

Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s Otodus and Squalicorax

Squalicorax

Squalicorax is a genus of extinct lamniform shark known to have lived during the Cretaceous period. A fully articulated 1.9 m long fossil skeleton of Squalicorax has been found in Kansas, evidence of its presence in the Western Interior Seaway...

, the sea turtle

Sea turtle

Sea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...

 Toxochelys

Toxochelys

Toxochelys is an extinct genus of sea turtle from the Cretaceous period. It is the most commonly found fossilized turtle species in the Smoky Hill Chalk, in western Kansas. Toxochelys was about 2 m in length...

, and mosasaur

Mosasaur

Mosasaurs are large extinct marine lizards. The first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764...

s including Plioplatecarpus

Plioplatecarpus

Plioplatecarpus is a genus of mosasaur lizard. Like all mosasaurs, it lived in the late Cretaceous period, about 83.5 million years ago.-Description:...

and Globidens

Globidens

Globidens is an extinct genus of mosasaur lizard.Globidens alabamaensis was first described by Gilmore . A second species was described by Russell . The third North American species Globidens ("Globe teeth") is an extinct genus of mosasaur lizard.Globidens alabamaensis was first described by...

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

Frontal bone

The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:* a vertical portion, the squama frontalis, corresponding with the region of the forehead....

 and widely spaced supratemporal fenestrae, distinguish it from the closely related Thoracosaurus neocesariensis

Thoracosaurus

Thoracosaurus is an extinct genus of gavialoid crocodilian which existed during the Late Cretaceous and early Paleocene. It contains the species Thoracosaurus neocesariensis in North America and Thoracosaurus macrorhynchus in Europe. A number of species have been referred to this genus, but most...

from the late Maastrichtian and early Paleocene

Paleocene

The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...

 of New Jersey

New Jersey

New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

.