''Guchengosuchus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

erythrosuchid Erythrosuchidae (meaning "red crocodiles" in Greek) are a family of large basal archosauriform carnivores that lived from the later Early Triassic (Olenekian) to the early Middle Triassic (Anisian). Naming The family Erythrosuchidae was named b ...

archosauriform Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Latest Permian (roughly 252 million years ago). It was defined by Jacques Gauthier ...

from the

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a un ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. It is known from a single

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

skeleton called

IVPP The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name suggest ...

V 8808, described in 1991 from the lower

Ermaying Formation The Ermaying Formation is a sedimentary succession of Anisian (Middle Triassic) age. It is found in the Shaanxi Province of China. It is composed of an up to 600 m thick sequence of mudstone and sandstone. It is famous for its fossils of tetrapods. ...

Shanxi Shanxi (; ; formerly romanised as Shansi) is a landlocked province of the People's Republic of China and is part of the North China region. The capital and largest city of the province is Taiyuan, while its next most populated prefecture-lev ...

. The lower Ermaying Formation dates back to the

Olenekian In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between Ma and Ma (million years ago). The Olenekian is sometimes divided into ...

stage of the Early Triassic, making ''Guchengosuchus'' one of the earliest archosauriforms. IVPP V 8808 is a disarticulated skeleton including a partial skull, lower jaw, some vertebrae, a

scapula The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...

, and forelimb bones. Like some other erythrosuchids, ''Guchengosuchus'' has a tall skull with a notch between the

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

and

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

bones of the upper jaw. The ribs of ''Guchengosuchus'' each have three

heads A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...

, a feature also seen in the Russian erythrosuchid ''

Vjushkovia ''Garjainia'' is an extinct genus of erythrosuchid archosauriform reptile from the Olenekian of Russia and South Africa. It was approximately 1.50–2 m (5–6 ft 8 in) long. It contained two species, ''Garjainia prima'' from the Yarengian/ ...

''. When it was first described, ''Guchengosuchus'' was placed in the suborder

Proterosuchia Proterosuchia is one of the suborders of the paraphyletic group Thecodontia; containing the most primitive and ancestral forms. These were primitive, vaguely crocodile-like, archosauriforms that mostly lived during the Early Triassic epoch. Th ...

, a group that included the families Erythrosuchidae,

Proterosuchidae Proterosuchidae is an early family of basal archosauriforms whose fossils are known from the Latest Permian and the Early Triassic of Europe, Asia, Africa, Australia and possibly South America. The name comes from Greek πρότερο- ("first") ...

, and

Proterochampsidae Proterochampsidae is a family of proterochampsian archosauriforms. Proterochampsids may have filled an ecological niche similar to modern crocodiles, and had a general crocodile-like appearance. They lived in what is now South America in the Mid ...

and was thought to be closely related to a primitive group of reptiles called

Eosuchia Eosuchians are an extinct order of diapsid reptiles. Depending on which taxa are included the order may have ranged from the late Carboniferous to the Eocene but the consensus is that eosuchians are confined to the Permian and Triassic. Eosuch ...

. Proterosuchia is now considered a

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

assemblage of basal archosauriforms representing a series of successive branches of

stem group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

archosaurs.

References

External links

''Guchengosuchus shiguaiensis''
in the

Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ...

Early Triassic reptiles of Asia Erythrosuchids Fossil taxa described in 1991 Prehistoric reptile genera {{paleo-reptile-stub