Doswellia
Encyclopedia
Doswellia is an extinct genus
of archosauriform. It has been placed in its own family
, Doswellidae, and its own suborder, Doswelliina. It was a terrestrial
carnivore
that existed in eastern North America
during the Carnian
stage
of the Late Triassic
. Fossils have been found from the Poor Farm Member of the Falling Creek Formation in Virginia
. The formation, which is found in the Taylorsville basin, is part of the larger Newark Supergroup. Doswellia is named after Doswell
, the town from which remains have been found.
, Doswellia kaltenbachi, was described by Weems in 1980. Weems placed Doswellia within Thecodontia, a group of archosaurs that traditionally included many Triassic archosaurs. He placed the genus within its own family, Doswelliidae
, and suborder, Dosweliina. Parrish (1993) placed Doswellia among the most primitive of the crurotarsans, a group that includes crocodilians and their extinct relatives. More recently, Dilkes and Sues (2009) proposed a close relationship between Doswellia and the early archosauriform family Proterochampsidae
. Desojo et al. (2011) added the Brazilian archosauriforms Tarjadia
and Archeopelta
to Doswelliidae, and found support for Dilkes and Sues' classification in their own phylogenetic analysis.
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 archosauriform. It has been placed in its own family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Doswellidae, and its own suborder, Doswelliina. It was a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
carnivore
Carnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
that existed in eastern 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...
during the Carnian
Carnian
The Carnian is the lowermost stage of the Upper Triassic series . It lasted from about 228.7 till 216.5 million years ago . The Carnian is preceded by the Ladinian and is followed by the Norian...
stage
Faunal stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.Rock...
of the Late Triassic
Late Triassic
The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...
. Fossils have been found from the Poor Farm Member of the Falling Creek Formation in Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
. The formation, which is found in the Taylorsville basin, is part of the larger Newark Supergroup. Doswellia is named after Doswell
Doswell, Virginia
Doswell is an unincorporated community in Hanover County in the Central Region of the U.S. state of Virginia. Originally called Hanover Junction, it was located on the Virginia Central Railroad, which later became part of the Chesapeake and Ohio Railroad at a crossing of the Richmond,...
, the town from which remains have been found.
Taxonomy
The type speciesType 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...
, Doswellia kaltenbachi, was described by Weems in 1980. Weems placed Doswellia within Thecodontia, a group of archosaurs that traditionally included many Triassic archosaurs. He placed the genus within its own family, Doswelliidae
Doswelliidae
Doswelliidae is a family of carnivore archosauriforms. Doswelliids existed in North and South America during the Middle–Late Triassic period and were among the most derived non-archosaurian archosauriforms. The family was named by R. E. Weems in 1980 and it has been placed in its own suborder,...
, and suborder, Dosweliina. Parrish (1993) placed Doswellia among the most primitive of the crurotarsans, a group that includes crocodilians and their extinct relatives. More recently, Dilkes and Sues (2009) proposed a close relationship between Doswellia and the early archosauriform family Proterochampsidae
Proterochampsidae
Proterochampsidae is a family of 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 Middle and Late Triassic....
. Desojo et al. (2011) added the Brazilian archosauriforms Tarjadia
Tarjadia
Tarjadia is an extinct genus of Triassic archosauriform. It is known from a single species, T. ruthae, first described in 1998 from the Middle Triassic Los Chañares Formation in Argentina. Partial remains have been found from deposits that are Anisian-Ladinian in age. The genus is known mostly from...
and Archeopelta
Archeopelta
Archeopelta is an extinct genus of carnivorous archosauriform from the late Middle or early Late Triassic period . It is a doswelliid which lived in what is now southern Brazil. It is known from the holotype CPEZ-239a, which consists of partial skeleton and braincase...
to Doswelliidae, and found support for Dilkes and Sues' classification in their own phylogenetic analysis.