| Dongusuchus | |
|---|---|
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | †Aphanosauria |
| Genus: | †Dongusuchus Sennikov,1988 |
| Type species | |
| †Dongusuchus efremovi Sennikov, 1988 | |
Dongusuchus (meaningDonguz River crocodile inGreek, for the area where thetype specimen was found[1]) is anextinctgenus ofarchosaur.Fossils have been found from theDonguz Formation outcropping on the banks of theDonguz River in theOrenburg Oblast ofRussia. They are associated with a fossil assemblage called theEryosuchus Fauna, named after thecapitosauridEryosuchus, the most common organism found from the assemblage. The locality dates back to theAnisian and earlyLadinian stages of theMiddle Triassic.[2]
Sennikov (1988) and Gower and Sennikov (2000) suggested thatDongusuchus was a gracile rauisuchian with a long,sigmoidally curved neck, unlike the more typical robust short-necked rauisuchians that appear later in theTriassic.[1][2] More recently, Nesbitt (2009) argued thatDongusuchus most probably represents a non-archosaurian archosauriform. According to Nesbitt (2009), the poorly-defined crista tibiofibularis and the absence of a distinct anteromedial tuber of the proximal portion of the thighbone inDongusuchus suggest that it is not a member of Archosauria. Although Gower and Sennikov (2000) suggested that the distinct sigmoidal shape ofDongusuchusfemur is unique, a similar shape is present in the femora of somephytosaurs. Aparatype tibia was also found to be more closely related toEuparkeria and phytosaurs, on the basis of its convex and rounded distal surface. Additionally, the proximal surface of the tibia lacks a trait present in nearly allpseudosuchians, a depression on its lateral condyle. Nesbitt assignedDongusuchus to Archosauriformes on the basis of the following traits: its femur has a low fourth trochanter, and the distal condyles do not expand markedly beyond the shaft. These traits suggest thatDongusuchus was an archosauriform more derived thanErythrosuchus.[3]
Dongusuchus was also excluded from Archosauria by Niedźwiedzki et al. (2014)[4] and a new large cladistic analysis of archosauromorphs by Ezcurra (2016)[5] foundDongusuchus to be thesister taxon to the IndianYarasuchus. BothDongusuchus andYarasuchus were recovered in a clade withSpondylosoma andTeleocrater by Nesbitt et al. (2017)[6] at the base of Avemetatarsalia, making them bird-line archosaurs.
 | This article about aprehistoricarchosaur is astub. You can help Wikipedia byexpanding it. |
