Garjainia Madiba
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''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 rhynchocephalians ( ...
from the Olenekian of
Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
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 countri ...
. 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 fossilife ...
( ''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
Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
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
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 countri ...
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 a un ...
(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 Beaufo ...
''. 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''.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 ani ...
. These bosses are one of the autapomorphies of ''Garjainia''.


Classification

Garjainia was an
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 ...
. 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 (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 ...
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 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