Tecovasuchus 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 aetosaur

Aetosaur

Aetosaurs are an extinct order of heavily armoured, medium- to large-sized Late Triassic herbivorous archosaurs. They have small heads, upturned snouts, erect limbs, and a body covered by plate-like scutes. All aetosaurs belong to the family Stagonolepididae...

. It is known primarily from osteoderm

Osteoderm

Osteoderms are bony deposits forming scales, plates or other structures in the dermal layers of the skin. Osteoderms are found in many groups of extant and extinct reptiles, including lizards, various groups of dinosaurs , crocodilians, phytosaurs, aetosaurs, placodonts, and hupehsuchians...

s found from the Tecovas Formation

Tecovas Formation

-Vertebrate fauna:...

 in Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

, which is Late Triassic

Late Triassic

The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...

 in age, dating back to the upper Carnian

Carnian

The Carnian is the lowermost stage of the Upper Triassic series . It lasted from about 228.7 till 216.5 million years ago . The Carnian is preceded by the Ladinian and is followed by the Norian...

. Material is also known from several other localities of the Chinle Group in New Mexico

New Mexico

New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 and Arizona

Arizona

Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

. Specimens of Tecovasuchus have been collected from the Tecovas Formation, the Bluewater Creek Formation, and the Los Esteros Member of the Santa Rosa Formation

Santa Rosa Formation

The Santa Rosa Formation is a Mesozoic geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.-See also:* List of dinosaur-bearing rock formations...

.

Tecovasuchus was first recognized as a new taxon in 1995, although it was not named until the description of the type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

, T. chatterjeei, in 2006. Before its description, specimens of Tecovasuchus were thought to belong to Paratypothorax

Paratypothorax

Paratypothorax is an extinct genus of aetosaur. It was first named in 1985 from specimens collected from the Lower Stubensandstein in Germany and was also noted to be present in the Chinle Group of the southwestern United States in both the Dockum and Chinle Formations, which are latest Carnian and...

or a Paratypothorax-like aetosaur. Several features of the osteoderms distinguish Tecovasuchus from other aetosaur genera, including dorsal paramedian osteoderms with strongly thickened and beveled posterior edges and ornamentation consisting of deep pits and radiating grooves, as well as tongue-shaped dorsal and plate-like ventrolateral flanges.

Tecovasuchus is an index taxon

Index fossil

Index fossils are fossils used to define and identify geologic periods . They work on the premise that, although different sediments may look different depending on the conditions under which they were laid down, they may include the remains of the same species of fossil...

 for the St. Johnsian sub-land vertebrate faunachron of the Adamanian Land vertebrate faunachron, and the presence of material belonging to the genus helps correlate different Late Triassic localities throughout the southwestern United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.