Dongusuchus 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 rauisuchia

Rauisuchia

Rauisuchia is a group of predatory and mostly large Triassic archosaurs. As a clade, Rauisuchia includes these Triassic forms and all crocodylomorphs, which are descendants of Triassic rauisuchians. The group in its traditional sense is paraphyletic, because it does not include crocodylomorph...

n. Fossil

Fossil

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

s have been found from the Donguz Formation outcropping on the banks of the Donguz River in the Orenburg Oblast

Orenburg Oblast

Orenburg Oblast is a federal subject of Russia . Its administrative center is the city of Orenburg. From 1938 to 1957, it bore the name Chkalov Oblast in honor of Valery Chkalov...

 of Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. They are associated with a fossil assemblage called the Eryosuchus Fauna, named after the capitosaurid Eryosuchus

Eryosuchus

Eryosuchus is an extinct genus of temnospondyl amphibian from the Middle Triassic of northern Russia.-Sources:* The Age of Dinosaurs in Russia and Mongolia by Michael J. Benton, Mikhail A. Shishkin, David M. Unwin, and Evgenii N. Kurochkin. p. 35-59.* Dinosaur Encyclopedia by Jayne Parsons* Chinese...

, the most common organism found from the assemblage. The locality dates back to the Anisian

Anisian

In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 245 million years ago until 237 million years ago, approximately...

 and early Ladinian

Ladinian

The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between 237 ± 2 Ma and 228 ± 2 Ma...

 stages of the Middle Triassic

Middle Triassic

In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between 245 ± 1.5 Ma and 228 ± 2 Ma...

.

Dongusuchus was a gracile rausuchian with a long, sigmoidal

Sigmoidal

Sigmoidal or sigmoid, literally means S-shaped and can refer to:* Sigmoid function* Sigmoidal artery* Sigmoid colon...

ly curved neck, unlike the more typical robust short-necked rauisuchians that appear later in the Triassic

Triassic

The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

.