Proterosuchus
Encyclopedia
Proterosuchus is an extinct genus
of Early Triassic
proterosuchid
archosaur
. Remains have been found from South Africa
and China
. The genus Chasmatosaurus is considered a junior synonym of Proterosuchus, as all species of Chasmatosaurus, including C. aleandri, C. vanhoepeni, and C. yuani, have been reassigned to Proterosuchus. Elaphrosuchus has also been synonymized with Proterosuchus. The type species
of Proterosuchus is P. fergusi. Two other species, P. ultimus and P. yuani, have also been named.
period, equivalent in size to today's Komodo dragon
s. It looked somewhat similar to a primitive crocodile
, and shared many of their modern features like long jaws, powerful neck muscles, short legs and a lengthy tail, while possessing several features unique to proterosuchids such as its hook-shaped mouth. This jaw may have been an adaptation for catching prey, such as the dicynodont
Lystrosaurus
. Proterosuchus, like most modern crocodiles, is theorised to be an ambush predator, waiting for its prey to enter the water, at which point they would be attacked from below the surface, using the long, muscular tail for swimming and pushing through the water at speed. However, the animal also had stout legs that enabled it to walk comfortably at land. Being able to move between the land and the water was a great advantage, and enabled Proterosuchus to control its body temperature by sunbathing or cooling off in the water. Being an ambush predator like some present-day crocodile
s meant that for the most part Proterosuchus remained in one environment for most of its life. This worked as an excellent means of conserving energy, even giving it the capability of surviving for perhaps months at a time without food.
Although it could live and swim in the water, Proterosuchus may have preferred to hunt land animals rather than fish. Its eyes were located on the top of its head, allowing it to hide just under the surface of the water, where it would wait for animals to come and drink. When close enough, Proterosuchus would spring upwards and drag its victim into the water, drowning and then eating it.
Comparisons between the scleral ring
s of Proterosuchus and modern birds and reptiles indicates that it may have been cathemeral
, active throughout the day during short intervals, supporting the idea that early archosaur
s adapted to dim light. However, as Proterosuchus may have been a polar
animal, it likely lived under different lighting conditions from typical archosaurs and may not have inherited such adaptations from a common ancestor with archosaurs.
The type species of Proterosuchus is P. fergusi, named by Robert Broom
in 1903 from Tarkastad, Eastern Cape in South Africa. It has been found from the Lystrosaurus Assemblage Zone
of the Beaufort Group
in the Karoo
. Several other species of proterosuchids have been described from the Karoo, including Chasmatosaurus vanhoepeni in 1924, Elaphrosuchus rubidgei in 1946, and Chasmatosaurus alexandri in 1965. These species were distinguishable from one another on the basis of size-related characteristics. More recently, these characteristics have been considered to represent different stages in the growth series of one species. Because the name Proterosuchus fergusi has seniority, the other species have been synonymized with P. fergusi.
A new species of Chasmatosaurus, C. yuani, was described from Xinjiang
, China
in 1936. It has been found from the Cangfanggou Group near Jimsar, northeast of Ürümqi
. It was reassigned as a new species of Proterosuchus in 1970.
s, dinosaur
s, and bird
s. It was once believed to have been an ancestor to the crocodilians, but it is now known to be far more basal.
as well as in the BBC documentary Walking with Monsters
.
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 Early Triassic
Early Triassic
The Early Triassic is the first of three epochs of the Triassic period of the geologic timescale. It spans the time between 251 ± 0.4 Ma and 245 ± 1.5 Ma . Rocks from this epoch are collectively known as the Lower Triassic, which is a unit in chronostratigraphy...
proterosuchid
Proterosuchidae
Proterosuchidae is an early, possibly paraphyletic, assemblage of basal archosauriformes whose fossils are known from the Latest Permian of Russia and the Early Triassic of southern Africa, Russia, China, Australia, and Antarctica...
archosaur
Archosaur
Archosaurs are a group of diapsid amniotes whose living representatives consist of modern birds and crocodilians. This group also includes all extinct non-avian dinosaurs, many extinct crocodilian relatives, and pterosaurs. Archosauria, the archosaur clade, is a crown group that includes the most...
. Remains have been found from South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. The genus Chasmatosaurus is considered a junior synonym of Proterosuchus, as all species of Chasmatosaurus, including C. aleandri, C. vanhoepeni, and C. yuani, have been reassigned to Proterosuchus. Elaphrosuchus has also been synonymized with Proterosuchus. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of Proterosuchus is P. fergusi. Two other species, P. ultimus and P. yuani, have also been named.
Description
Proterosuchus was one of the largest land reptile during the Early TriassicEarly Triassic
The Early Triassic is the first of three epochs of the Triassic period of the geologic timescale. It spans the time between 251 ± 0.4 Ma and 245 ± 1.5 Ma . Rocks from this epoch are collectively known as the Lower Triassic, which is a unit in chronostratigraphy...
period, equivalent in size to today's Komodo dragon
Komodo dragon
The Komodo dragon , also known as the Komodo monitor, is a large species of lizard found in the Indonesian islands of Komodo, Rinca, Flores, Gili Motang and Gili Dasami. A member of the monitor lizard family , it is the largest living species of lizard, growing to a maximum length of in rare cases...
s. It looked somewhat similar to a primitive crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
, and shared many of their modern features like long jaws, powerful neck muscles, short legs and a lengthy tail, while possessing several features unique to proterosuchids such as its hook-shaped mouth. This jaw may have been an adaptation for catching prey, such as the dicynodont
Dicynodont
Dicynodontia is a taxon of anomodont therapsids or mammal-like reptiles. Dicynodonts were small to large herbivorous animals with two tusks, hence their name, which means 'two dog tooth'...
Lystrosaurus
Lystrosaurus
Lystrosaurus was a genus of Late Permian and Early Triassic Period dicynodont therapsids, which lived around 250 million years ago in what is now Antarctica, India, and South Africa...
. Proterosuchus, like most modern crocodiles, is theorised to be an ambush predator, waiting for its prey to enter the water, at which point they would be attacked from below the surface, using the long, muscular tail for swimming and pushing through the water at speed. However, the animal also had stout legs that enabled it to walk comfortably at land. Being able to move between the land and the water was a great advantage, and enabled Proterosuchus to control its body temperature by sunbathing or cooling off in the water. Being an ambush predator like some present-day crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
s meant that for the most part Proterosuchus remained in one environment for most of its life. This worked as an excellent means of conserving energy, even giving it the capability of surviving for perhaps months at a time without food.
Comparisons between the scleral ring
Sclerotic ring
Sclerotic rings are rings of bone found in the eyes of several groups of vertebrate animals, except for mammals and crocodilians. They can be made up of single bones or small bones together. They are believed to have a role in supporting the eye, especially in animals whose eyes are not spherical,...
s of Proterosuchus and modern birds and reptiles indicates that it may have been cathemeral
Cathemeral
A cathemeral organism is one that has sporadic and random intervals of activity during the day or night in which food is acquired, socializing with other organisms occurs, and any other activities necessary for livelihood are performed...
, active throughout the day during short intervals, supporting the idea that early archosaur
Archosaur
Archosaurs are a group of diapsid amniotes whose living representatives consist of modern birds and crocodilians. This group also includes all extinct non-avian dinosaurs, many extinct crocodilian relatives, and pterosaurs. Archosauria, the archosaur clade, is a crown group that includes the most...
s adapted to dim light. However, as Proterosuchus may have been a polar
Polar region
Earth's polar regions are the areas of the globe surrounding the poles also known as frigid zones. The North Pole and South Pole being the centers, these regions are dominated by the polar ice caps, resting respectively on the Arctic Ocean and the continent of Antarctica...
animal, it likely lived under different lighting conditions from typical archosaurs and may not have inherited such adaptations from a common ancestor with archosaurs.
Species
Robert Broom
Professor Robert Broom was a Scottish South African doctor and paleontologist. He qualified as a medical practitioner in 1895 and received his DSc in 1905 from the University of Glasgow...
in 1903 from Tarkastad, Eastern Cape in South Africa. It has been found from the Lystrosaurus Assemblage Zone
Lystrosaurus Assemblage Zone
The Lystrosaurus Assemblage Zone is a geological stratum and a faunal zone of the Beaufort Group, of the South African Karoo. The name refers to Lystrosaurus, a genus of mammal-like reptile, a dominant life form of the Early Triassic Period, whose fossils have been found in that structure....
of the Beaufort Group
Beaufort Group
The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup of geological strata in Southern Africa. It follows conformably after the Ecca Group and consists essentially of sandstones and shales, deposited in the Karoo Basin from the Middle Permian to the early part of the...
in the Karoo
Karoo
The Karoo is a semi-desert region of South Africa. It has two main sub-regions - the Great Karoo in the north and the Little Karoo in the south. The 'High' Karoo is one of the distinct physiographic provinces of the larger South African Platform division.-Great Karoo:The Great Karoo has an area of...
. Several other species of proterosuchids have been described from the Karoo, including Chasmatosaurus vanhoepeni in 1924, Elaphrosuchus rubidgei in 1946, and Chasmatosaurus alexandri in 1965. These species were distinguishable from one another on the basis of size-related characteristics. More recently, these characteristics have been considered to represent different stages in the growth series of one species. Because the name Proterosuchus fergusi has seniority, the other species have been synonymized with P. fergusi.
Xinjiang
Xinjiang is an autonomous region of the People's Republic of China. It is the largest Chinese administrative division and spans over 1.6 million km2...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
in 1936. It has been found from the Cangfanggou Group near Jimsar, northeast of Ürümqi
Ürümqi
Ürümqi , formerly Tihwa , is the capital of Xinjiang Uyghur Autonomous Region of the People's Republic of China, in the northwest of the country....
. It was reassigned as a new species of Proterosuchus in 1970.
Classification
Proterosuchus is an example of an early archosaur, the group which encompasses crocodiles, pterosaurPterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
s, dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
s, and bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. It was once believed to have been an ancestor to the crocodilians, but it is now known to be far more basal.
Popular culture
Proterosuchus was featured in episode 5 of Animal ArmageddonAnimal Armageddon
Animal Armageddon is an American paleontology-based documentary television miniseries that originally aired from to on Animal Planet. All the prehistoric scenes are created 100% in Lightwave...
as well as in the BBC documentary Walking with Monsters
Walking with Monsters
Walking with Monsters is a three-part British documentary film series about life in the Paleozoic, bringing to life extinct arthropods, fish, amphibians, synapsids, and reptiles...
.