Krabisuchus
Encyclopedia
Krabisuchus is an extinct alligatorine
which existed in what is now Thailand
during the late Eocene
. It was first named by paleontologists Jeremy A. Martin and Komsorn Lauprasert in 2010, and the type species
is K. siamogallicus. Fossils have been found from the Krabi Basin of southern Thailand
and include mostly cranial
and mandibular
elements as well as some postcranial remains. Krabisuchus is currently the most well known primitive alligatorine from Asia; previously, these animals were only represented in Asia by a few fragmentary remains from China
. The fossil record of alligatorines is much more extensive in Europe
and North America
, where most taxa have been described.
Growing to approximately 2 metres (6.6 ft) in length, Krabisuchus was a small alligatorine that was much smaller than the living alligator
. Like the alligator, it had a blunt snout. Krabisuchus also had a raised skull similar to the extinct alligatorine Arambourgia
and living crocodile
Osteolaemus tetraspis. The teeth at the back of the jaws were very blunt. It, like other extinct alligatorines, was probably terrestrial rather than semiaquatic. This terrestrial lifestyle may have allowed other alligatorines to colonize much of the northern hemisphere during the Paleogene
when global temperatures were much warmer than they are today.
Krabisuchus is closely related to the extinct alligatorines Arambourgia, Allognathosuchus
, and Procaimanoidea
. These taxa are considered sister groups of the Alligator clade
.
Alligatorinae
Alligatorinae are one of two subfamilies of the family Alligatoridae.-Taxonomy:* Subfamily Alligatorinae** Genus Chrysochampsa ** Genus Hassiacosuchus ** Genus Navajosuchus ** Genus Ceratosuchus...
which existed in what is now Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
during the late Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
. It was first named by paleontologists Jeremy A. Martin and Komsorn Lauprasert in 2010, and 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...
is K. siamogallicus. Fossils have been found from the Krabi Basin of southern Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
and include mostly cranial
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
and mandibular
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
elements as well as some postcranial remains. Krabisuchus is currently the most well known primitive alligatorine from Asia; previously, these animals were only represented in Asia by a few fragmentary remains from 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 fossil record of alligatorines is much more extensive in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, where most taxa have been described.
Growing to approximately 2 metres (6.6 ft) in length, Krabisuchus was a small alligatorine that was much smaller than the living alligator
Alligator
An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. There are two extant alligator species: the American alligator and the Chinese alligator ....
. Like the alligator, it had a blunt snout. Krabisuchus also had a raised skull similar to the extinct alligatorine Arambourgia
Arambourgia
Arambourgia is an extinct genus of alligatorine crocodylian from Europe. It was named in 1905 and synonymized with Allognathosuchus haupti in 1990, but later reassigned as its own genus once again in 2004. It is thought to have been closely related to Hispanochampsa and Procaimanoidea...
and living 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...
Osteolaemus tetraspis. The teeth at the back of the jaws were very blunt. It, like other extinct alligatorines, was probably terrestrial rather than semiaquatic. This terrestrial lifestyle may have allowed other alligatorines to colonize much of the northern hemisphere during the Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
when global temperatures were much warmer than they are today.
Krabisuchus is closely related to the extinct alligatorines Arambourgia, Allognathosuchus
Allognathosuchus
Allognathosuchus is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. This small alligatorine is known for its stout jaws and bulbous teeth, found near the rear of the tooth row in upper and lower jaws. These adaptations have historically been interpreted as...
, and Procaimanoidea
Procaimanoidea
Procaimanoidea is an extinct genus of alligatorid from the Eocene of North America. It was named posthumously in 1946 by Charles W. Gilmore; the type species is P. utahensis, from the Uintan of Utah. It is based on USNM 15996, a nearly complete skull and partial left hind leg. A second species,...
. These taxa are considered sister groups of the Alligator clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
.