Chilantaisaurus
Encyclopedia
Chilantaisaurus is a genus
of neovenatorid
theropod dinosaur
from the late Cretaceous
Ulansuhai Formation
of China
(Turonian
stage, about 92 million years ago). The type species
, C. tashuikouensis, was described by Hu in 1964. Chilantaisaurus was a large theropod, estimated as weighing between 2.5 metric tons (2.8 ST) and 4 metric tons (4.4 ST). Recently, Brusatte et al. (2010) estimated it to weight 6000 kilograms (13,227.7 lb).
, though some subsequent studies suggested that it may be a spinosauroid, possibly a primitive member of the spinosaurid family (Sereno, 1998; Chure, 2002; Rauhut, 2001) because it had large claw on the forelimbs thought to be unique to that group. Other studies suggested that it could be a member of an alternate offshoot of neotetanuran
theropods, with some similarities to allosauroids, spinosauroids, and coelurosauria
ns. A 2009 study noted that it was difficult to rule out the possibility that Chilantaisaurus was the same animal as the carnosaur Shaochilong
, which is from the same geological formation. However, they did note an enormous size difference between the two. Further study by Benson, Carrano and Brusatte found that it was not as closely related to Shaochilong as first thought, but that it was a carnosaur (of the family Neovenatoridae
), closely related to Allosaurus as Hu had initially thought.
Several species have been described based on very poor remains. Chilantaisaurus? sibiricus is based on a single distal metatarsal IV from the Turginskaya Svita
of the Buryat Autonomous Soviet Socialist Republic
, Russia
, dating to the Early Cretaceous
(Berriasian
-Hauterivian
). It is poorly described, so its relationships cannot be accurately determined (Chure, 2002). "Chilantaisaurus" maortuensis was reclassified as Shaochilong maortuensis in 2009. Bones attributed to "Chilantaisaurus" zheziangensis come from a therizinosaur
, and may in fact come from the same individual as the type specimen
of Nanshiungosaurus
.
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 neovenatorid
Neovenatoridae
Neovenatoridae is a family of large carnivorous dinosaurs. The group is a branch of the allosauroids, a large group of carnosaurs that also includes the sinraptorids, carcharodontosaurids, and allosaurids...
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 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...
Ulansuhai Formation
Ulansuhai Formation
The Ulansuhai Formation is a geological formation in Inner Mongolia, north China. Dinosaur remains are among the fossils that have been recovered from the formation....
of 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...
(Turonian
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...
stage, about 92 million years ago). 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...
, C. tashuikouensis, was described by Hu in 1964. Chilantaisaurus was a large theropod, estimated as weighing between 2.5 metric tons (2.8 ST) and 4 metric tons (4.4 ST). Recently, Brusatte et al. (2010) estimated it to weight 6000 kilograms (13,227.7 lb).
Classification
Hu considered Chilantaisaurus to be a carnosaur related to AllosaurusAllosaurus
Allosaurus is a genus of large theropod dinosaur that lived 155 to 150 million years ago during the late Jurassic period . The name Allosaurus means "different lizard". It is derived from the Greek /allos and /sauros...
, though some subsequent studies suggested that it may be a spinosauroid, possibly a primitive member of the spinosaurid family (Sereno, 1998; Chure, 2002; Rauhut, 2001) because it had large claw on the forelimbs thought to be unique to that group. Other studies suggested that it could be a member of an alternate offshoot of neotetanuran
Tetanurae
Tetanurae, or "stiff tails", is a clade that includes most theropod dinosaurs, as well as birds. Tetanurans first appear during the early or middle Jurassic Period.-Definition:...
theropods, with some similarities to allosauroids, spinosauroids, and coelurosauria
Coelurosauria
Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...
ns. A 2009 study noted that it was difficult to rule out the possibility that Chilantaisaurus was the same animal as the carnosaur Shaochilong
Shaochilong
Shaochilong is a genus of carcharodontosaurid dinosaur from the mid Cretaceous Ulansuhai Formation of China . The type species, S...
, which is from the same geological formation. However, they did note an enormous size difference between the two. Further study by Benson, Carrano and Brusatte found that it was not as closely related to Shaochilong as first thought, but that it was a carnosaur (of the family Neovenatoridae
Neovenatoridae
Neovenatoridae is a family of large carnivorous dinosaurs. The group is a branch of the allosauroids, a large group of carnosaurs that also includes the sinraptorids, carcharodontosaurids, and allosaurids...
), closely related to Allosaurus as Hu had initially thought.
Several species have been described based on very poor remains. Chilantaisaurus? sibiricus is based on a single distal metatarsal IV from the Turginskaya Svita
Turginskaya Svita
The Turginskaya Svita is an Early Cretaceous geologic formation. Dinosaur remains have been recovered from it, including Chilantaisaurus? sibiricus.-See also:* List of dinosaur-bearing rock formations...
of the Buryat Autonomous Soviet Socialist Republic
Buryat Autonomous Soviet Socialist Republic
The Buryat Autonomous Soviet Socialist Republic was an Autonomous Soviet Socialist Republic in the former Soviet Union....
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, dating to the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
(Berriasian
Berriasian
In the geological timescale, the Berriasian is an age or stage of the Early or Lower Creteceous. It is the oldest or lowest subdivision in the entire Cretaceous. It spanned between 145.5 ± 4.0 Ma and 140.2 ± 3.0 Ma...
-Hauterivian
Hauterivian
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous epoch or a stage in the Lower Cretaceous series. It spans the time between 136.4 ± 2 Ma and 130 ± 1.5 Ma...
). It is poorly described, so its relationships cannot be accurately determined (Chure, 2002). "Chilantaisaurus" maortuensis was reclassified as Shaochilong maortuensis in 2009. Bones attributed to "Chilantaisaurus" zheziangensis come from a therizinosaur
Therizinosaur
Therizinosaurs are theropod dinosaurs belonging to the clade Therizinosauria. Therizinosaur fossils have been found in Early through Late Cretaceous deposits in Mongolia, the People's Republic of China and Western North America...
, and may in fact come from the same individual as the type specimen
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...
of Nanshiungosaurus
Nanshiungosaurus
Nanshiungosaurus is a genus of therizinosaurian theropod dinosaur from the Cretaceous of China.Two species have been named in the genus: the type species Nanshiungosaurus brevispinus and Nanshiungosaurus bohlini.-Discovery and naming:...
.
External links
- Chilantaisaurus in the Dinosaur Encyclopedia