Tsaagan
Encyclopedia
Tsaagan is a genus
of carnivorous dromaeosaurid theropod dinosaur
from the Djadokhta Formation of the late Cretaceous
of Mongolia
.
The fossil of Tsaagan was discovered in 1996 and first identified as a specimen of Velociraptor
. After a CAT-scan in May 1998 it was concluded that it represented a new genus. In December 2006 its type species
was named and described by Mark Norell, James Clark
, Alan Turner
, Peter Makovicky, Rinchen Barsbold and Timothy Rowe. The species name, Tsaagan mangas, should be read as a whole with the generic name qualifying the specific epithet, and is derived from the Mongolian words for "white monster" , although with an accidental misspelling of the word Tsagaan
.
The holotype
specimen, IGM 100/1015, was found near Xanadu
in Ömnögovi Province
in layers of the Djadokhta Formation dating to the Campanian
, about 75 million years ago. It consists of a well-preserved skull and series of ten neck vertebrae as well as a damaged left shoulder girdle. It is the only specimen found of Tsaagan and belonged to an adult individual.
Tsaagan was a medium-sized dromaeosaurid. In 2010 Gregory S. Paul
estimated its length at two metres, its weight at fifteen kilogrammes. The skull in general appearance resembles that of Velociraptor but differs from it in many details. It is more robust and smooth on top; unique derived traits, autapomorphies
, include long paroccipital processes and basipterygoids at the back of the skull and a jugal
touching the squamosal
.
Tsaagan was assigned to the Dromaeosauridae
. A cladistic analysis by Norell et. al. indicated it was more precisely a member of the Velociraptorinae
. In 2010 an analysis showed it was closely related to Linheraptor
.
Tsaagan represents the only dromaeosaurid remains (other than isolated teeth) known from the Ukhaa Tolgod region, though another dromaeosaurid, Velociraptor
, is known from the same formation. Animals that may have shared the same habitat with Tsaagan include Protoceratops
, Shuvuuia
, the small mammal
Zalambdalestes
, the multituberculate mammal Kryptobaatar
, as well as several lizards and two yet-undescribed species of troodontid and dromaeosaurid.
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 carnivorous dromaeosaurid theropod 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...
from the Djadokhta Formation of the late Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
of Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
.
The fossil of Tsaagan was discovered in 1996 and first identified as a specimen of Velociraptor
Velociraptor
Velociraptor is a genus of dromaeosaurid theropod dinosaur that existed approximately 75 to 71 million years ago during the later part of the Cretaceous Period. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis; fossils...
. After a CAT-scan in May 1998 it was concluded that it represented a new genus. In December 2006 its 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...
was named and described by Mark Norell, James Clark
James Clark
James Clark may refer to:* James Clark , Ambassador from the United Kingdom to Luxembourg* James Clark , Governor of Kentucky from 1836 to 1839* James Clark , Mayor of Auckland...
, Alan Turner
Alan Turner
Alan Turner is a former Australian cricketer who played in 14 Tests and 6 ODIs from 1975 to 1977....
, Peter Makovicky, Rinchen Barsbold and Timothy Rowe. The species name, Tsaagan mangas, should be read as a whole with the generic name qualifying the specific epithet, and is derived from the Mongolian words for "white monster" , although with an accidental misspelling of the word Tsagaan
Tsagaan
- People :* Monguor or Tsagaan mongghol, a Mongol ethnic group in China* Okna Tsagaan Zam, a Kalmyk throat singer* Chagaan, the commander of the Mongol Empire, of Tangut origin.- Places :* Tsagaannuur, several places named "white lake"...
.
The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen, IGM 100/1015, was found near Xanadu
Xanadu
-Description of Xanadu by Toghon Temur :The lament of Toghon Temur Khan , concerning the loss of Daidu and Heibun Shanduu in 1368, is recorded in many Mongolian historical chronicles...
in Ömnögovi Province
Ömnögovi Province
Ömnögovi is an aimag of Mongolia, located in the south of the country, in the Gobi Desert. Ömnögovi is Mongolia's largest aimag. The capital is Dalanzadgad....
in layers of the Djadokhta Formation dating to the Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
, about 75 million years ago. It consists of a well-preserved skull and series of ten neck vertebrae as well as a damaged left shoulder girdle. It is the only specimen found of Tsaagan and belonged to an adult individual.
Tsaagan was a medium-sized dromaeosaurid. In 2010 Gregory S. Paul
Gregory S. Paul
Gregory Scott Paul is a freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dinosaurs and his detailed illustrations, both live and skeletal...
estimated its length at two metres, its weight at fifteen kilogrammes. The skull in general appearance resembles that of Velociraptor but differs from it in many details. It is more robust and smooth on top; unique derived traits, autapomorphies
Autapomorphy
In cladistics, an autapomorphy is a distinctive anatomical feature, known as a derived trait, that is unique to a given terminal group. That is, it is found only in one member of a clade, but not found in any others or outgroup taxa, not even those most closely related to the group...
, include long paroccipital processes and basipterygoids at the back of the skull and a jugal
Jugal
The jugal is a skull bone found in most reptiles, amphibians, and birds. In mammals, the jugal is often called the malar or Zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species....
touching the squamosal
Squamosal
The squamosal is a bone of the head of higher vertebrates. It is the principal component of the cheek region in the skull, lying below the temporal series and otic notch and bounded anteriorly by postorbital. Posteriorly, the squamosal articulates with the posterior elements of the palatal complex,...
.
Tsaagan was assigned to the Dromaeosauridae
Dromaeosauridae
Dromaeosauridae is a family of bird-like theropod dinosaurs. They were small- to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek dromeus meaning 'runner' and sauros meaning 'lizard'...
. A cladistic analysis by Norell et. al. indicated it was more precisely a member of the Velociraptorinae
Velociraptorinae
Velociraptorinae is a subfamily of the theropod group Dromaeosauridae. Velociraptorine remains are found mostly in northern hemisphere. In Late Cretaceous, they are mostly present in Mongolia, Romania and China,and in early, in USA. The earliest velociraptorines are probably Nuthetes from the...
. In 2010 an analysis showed it was closely related to Linheraptor
Linheraptor
Linheraptor is a genus of dromaeosaurid dinosaur which lived in what is now China in the Late Cretaceous. It was named by Xu Xing and colleagues in 2010, and contains the species Linheraptor exquisitus. This bird-like dinosaur was less than 2 m long and was found in Inner Mongolia...
.
Tsaagan represents the only dromaeosaurid remains (other than isolated teeth) known from the Ukhaa Tolgod region, though another dromaeosaurid, Velociraptor
Velociraptor
Velociraptor is a genus of dromaeosaurid theropod dinosaur that existed approximately 75 to 71 million years ago during the later part of the Cretaceous Period. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis; fossils...
, is known from the same formation. Animals that may have shared the same habitat with Tsaagan include Protoceratops
Protoceratops
Protoceratops is a genus of sheep-sized herbivorous ceratopsian dinosaur, from the Upper Cretaceous Period of what is now Mongolia. It was a member of the Protoceratopsidae, a group of early horned dinosaurs...
, Shuvuuia
Shuvuuia
Shuvuuia is a genus of bird-like theropod dinosaur from the late Cretaceous period of Mongolia. It is a member of the family Alvarezsauridae, small coelurosaurian dinosaurs which are characterized by short but powerful forelimbs specialized for digging. The type species is Shuvuuia deserti, or...
, the small mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
Zalambdalestes
Zalambdalestes
Zalambdalestes was a placental mammal living during the Upper Cretaceous in Mongolia. It is one of the oldest examples of a placental mammal known, and would have lived alongside the dinosaurs....
, the multituberculate mammal Kryptobaatar
Kryptobaatar
Kryptobaatar and also known as Gobiaatar, Gobibaatar or Tugrigbaatar is an extinct mammalian genus dating from the Upper Cretaceous Period and identified in Central Asia...
, as well as several lizards and two yet-undescribed species of troodontid and dromaeosaurid.