''Garjainia'' is an extinct genus of

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 ...

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...

from 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 i ...

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

and

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

. It was approximately 1.50–2 m (5–6 ft 8 in) long. It contained two species, ''Garjainia prima'' from the Yarengian/Yarkenskian Supergorizont of Russia, and ''Garjainia madiba'' from the

Burgersdorp Formation The ''Cynognathus'' Assemblage Zone is a tetrapod biozone utilized in the Karoo Basin of South Africa. It is equivalent to the Burgersdorp Formation, the youngest lithostratigraphic formation in the Beaufort Group, which is part of the fossilif ...

( ''Cynognathus'' Assemblage Zone A) of South Africa. "''Vjuskovia triplicostata''", a name assigned to some erythrosuchid fossils from Russia, has been synonymized with ''Garjainia prima''.

Discovery

''Garjainia prima'' was first discovered in a small village in

by a farmer. The exact date of the discovery is not known but its believed to have been found some time in the early 1950s. An later find is ''G. madiba'', which was found in

in the 1960s. In the same locality another much larger erythrosuchid was also found, called '' Erythrosuchus africanus'', which was the one of the largest terrestrial predators of 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 ...

(250 million years ago)

Description

''Garjainia prima'' is believed to have been between 1.5-2 meters in length, with ''Garjainia madiba'' having a length of 2.5 meters. Apart from its much smaller size, it was quite similar to its close relative ''

Erythrosuchus ''Erythrosuchus'' (from el, ἐρυθρός , 'red' and el, σοῦχος , 'crocodile') is an extinct genus of archosauriform reptile from the Triassic of South Africa. Remains have been found from the Cynognathus Assemblage Zone of the Beauf ...

''. The skull was very large and extremely robust; the strong lower jaw was armed with robust, curved teeth, and the muzzle was high and narrow. The legs were short but sturdy, while the tail was shorter than that of other primitive archosauriforms such as ''

Proterosuchus ''Proterosuchus'' is an extinct genus of archosauriform reptiles that lived during the Early Triassic. It contains three valid species: the type species ''P. fergusi'' and the referred species ''P. alexanderi'' and ''P. goweri''. All three spec ...

''.The humerus was extremely massive in ''Garjainia'', while the shoulder blade was hourglass-shaped and the dorsal ribs were very elongated, giving the animal a high-profile. Two species belonging to this genus are known: ''Garjainia prima'' from Russia and ''G. madiba'' from South Africa. The African species differs from the Russian one in the presence of large bony protuberances on the lateral surfaces of the jugal and postorbital bones. ''G. madiba'' also has more teeth and a more elongated postacetabular process of the ilium. ''G. madiba'''s bosses are unknown among other erythrosuchids. The reason that these bosses are present is unknown. Possible solutions are that they were signs of maturity or

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

. These bosses are one of the autapomorphies of ''Garjainia''.

Classification

Garjainia was an

. It was originally described by Soviet researcher VG Otschev, who classified it in its own family, Garjainidae. However, another Soviet scientist, Tatarinov, considered the genera ''Erythrosuchus'' and ''Garjainia'' to be synonymous. ''Garjainia'' has since been classified as a separate genus, part of the Erythrosuchidae. In addition, attention has been drawn to the existence of many primitive characteristics in this animal, which has led to suggestions that ''Garjainia'' represents a transitional form between the Proterosuchidae (a large, likely

paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...

lineage) and the family Erythrosuchidae.David Gover. The tarsus of erythrosuchid archosaurs, and implications for early diapsid phylogeny . Zoological Journal of the Linnean Society , 1996, 116: 347–375. PDF online.

Phylogeny

Below is a

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

based on the phylogeny of Parrish (1992).

References

Erythrosuchids Early Triassic reptiles of Africa Early Triassic reptiles of Europe Prehistoric reptile genera {{paleo-reptile-stub