Gasosaurus
Encyclopedia
Gasosaurus was a tetanuran dinosaur
discovered in Dashanpu, China
. The scientific name, meaning "Gas Lizard", honours the gasoline
company that found the Dashanpu fossil quarry in Sichuan
Province, now named as the Lower Shaximiao Formation. It had strong legs but short arms, and like most theropods, it was a carnivore
. It measured between 3.5 to 4 m (11.5 to 13.1 ft) in length, with a weight of around 150 kilogram, placing it in the midrange of theropods by size. However, some estimates put its weight as high as 400 kilograms (881.8 lb), as very little is known about this dinosaur. It lived during the mid-Jurassic
period (Bathonian
and/ or Callovian
stages), around 164 million years ago.
The first and to date only fossil
s, albeit postcranial (missing the skull
), were recovered in 1985 during the construction of a gas facility, which explains the unusual name of the dinosaur. The fossils were defined as the type species
Gasosaurus constructus by the paleontologists Dong Zhiming
and Tang Zilu. There have still been very few fossils retrieved, so exact details are unknown. Specifically, no skull has been found. Some paleontologists have speculated that Gasosaurus and Kaijiangosaurus
may be one and the same species. Traditionally thought to be a megalosauroid, Holtz (2000) found it to be a basal coelurosauria
n, although later Holtz et al. (2004) suggested it was a basal carnosaur, possibly a sinraptorid
, on the basis of data from undescribed specimens. It may in fact be the most basal
coelurosaurian yet known, or may even be close to the common ancestor of the two groups; in any case, it represents one of the oldest definitive tetanuran theropods.
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...
discovered in Dashanpu, 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 scientific name, meaning "Gas Lizard", honours the gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
company that found the Dashanpu fossil quarry in Sichuan
Sichuan
' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...
Province, now named as the Lower Shaximiao Formation. It had strong legs but short arms, and like most theropods, it was a 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...
. It measured between 3.5 to 4 m (11.5 to 13.1 ft) in length, with a weight of around 150 kilogram, placing it in the midrange of theropods by size. However, some estimates put its weight as high as 400 kilograms (881.8 lb), as very little is known about this dinosaur. It lived during the mid-Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
period (Bathonian
Bathonian
In the geologic timescale the Bathonian is an age or stage of the Middle Jurassic. It lasted from approximately 167.7 Ma to around 164.7 Ma...
and/ or Callovian
Callovian
In the geologic timescale, the Callovian is an age or stage in the Middle Jurassic, lasting between 164.7 ± 4.0 Ma and 161.2 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian....
stages), around 164 million years ago.
Discovery and species
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s, albeit postcranial (missing the skull
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...
), were recovered in 1985 during the construction of a gas facility, which explains the unusual name of the dinosaur. The fossils were defined as 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...
Gasosaurus constructus by the paleontologists Dong Zhiming
Dong Zhiming
Dong Zhiming , from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, is one of China's leading paleontologists. He began working at the IVPP in 1962, learning from Yang Zhongjian who was director at the time...
and Tang Zilu. There have still been very few fossils retrieved, so exact details are unknown. Specifically, no skull has been found. Some paleontologists have speculated that Gasosaurus and Kaijiangosaurus
Kaijiangosaurus
Kaijiangosaurus is the name given to a genus of dinosaur from the Middle Jurassic. It was a theropod like Megalosaurus. Its fossils, fragmentary remains of the skull, cervical vertebrae and elements of the pectoral girdle and both limbs, were found in China...
may be one and the same species. Traditionally thought to be a megalosauroid, Holtz (2000) found it to be a basal 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...
n, although later Holtz et al. (2004) suggested it was a basal carnosaur, possibly a sinraptorid
Sinraptoridae
Sinraptorids were a family of carnivorous theropod dinosaurs. They tended to be large predators, some growing to sizes of . Sinraptorids are carnosaurs, and many were initially classified within Megalosauridae or Allosauridae prior to recent analysis...
, on the basis of data from undescribed specimens. It may in fact be the most basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
coelurosaurian yet known, or may even be close to the common ancestor of the two groups; in any case, it represents one of the oldest definitive tetanuran theropods.
External links
- Bristol University, England; source for the high weight estimate
- Thescelosaurus!
- Dinosaur.net; source for Chinese name