Gasosaurus

*Gasosaurus constructus*

***Gasosaurus*** (Chinese: 气龙属) 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 metres (11 to 13 ft) in length, with a weight of around 150 kilograms (330 lb), placing it in the midrange of theropods by size. However, some estimates put its weight as high as 400 kilograms (880 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.

## Discover and naming

The first and to date only fossils, albeit postcranial (missing the skull), were recovered in 1985 during the construction of a gas facility, which explains the dinosaur's unusual name. The fossils were defined as the type species *Gasosaurus constructus* by the paleontologists Dong Zhiming and Tang Zilu.

## Description

*Gasosaurus* is a carnivorous theropod with strong legs but short arms. It measured between 3.5 to 4 metres (11 to 13 ft) in length, with a weight of around 150 kilograms (330 lb). However, some estimates put its weight as high as 400 kilograms (880 lb), as very little is known it.

Many potentially informative features of the holotype skeleton (IVPP V7264) are difficult to assess based on published descriptions and images. The taxon represents a tetanuran based on the presence of a pubic peduncle of the ilium that is substantially larger than the ischial peduncle. Examination of casts reveals that the lesser trochanter does not rise above the level of the femoral head, and instead, the proximal portion of the femoral head is broken and the lesser trochanter reaches approximately midlevel of the head as in non-coelurosaurian tetanurans.

Furthermore, it is recognized by an amphiplatyan cervical centra with incipient weak ventral keel, dorsals with amphiplatyan centra, low neural arches and plate-like neural spines, dorsal neural spines lacking expanded bulks at tips, five sacral centra and arches firmly fused while neural spines not fused, presence of a humeral foramen, low ilium with a less developed anterior process, and distal ends of pubis and ischium expanded but lacking foot-like processes.

## Classification

Traditionally thought to be a megalosauroid, Holtz (2000) found it to be a basal coelurosaurian, although later Holtz *et al.* (2004) suggested it was a basal carnosaur (possibly a metriacanthosaurid) 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. Some paleontologists have speculated that *Gasosaurus* and *Kaijiangosaurus* may be one and the same species.

Because of the fragmentary nature of the known *Gasosaurus* fossils, it has an uncertain position within Tetanurae, and probably lays outside Coelurosauria. A detailed restudy of the holotype is underway that may change its classification.

## JPInstitute.com Description

Gasosaurus was a fierce and fast, medium-sized meat-eater. It may have been related to Megalosaurus, but very little fossil material has been found. It is known from only a few bones, so many of its exact features are educated guesses on the part of scientists.

The skull on the type specimen is complete conjecture. Described in 1985, it is possible that this dinosaur is the same as Kaijiangosaurus.

## Appearance in other media

### *Jurassic Park*

* Gasosaurus appeared in the Jurassic World toys.

## Links

https://web.archive.org/web/20040214155200fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_gasos.html

## References

1. ↑ Dong and Tang, 1985. A new Mid-Jurassic theropod (*Gasosaurus constructus* gen et sp. nov.) from Dashanpu, Zigong, Sichuan Province, China. Vertebrata PalAsiatica. 23(1), 77-82.[1]
2. ↑ Holtz, 2000. A new phylogeny of the carnivorous dinosaurs. Gaia. 15, 5-61.
3. ↑ Holtz TR Jr, Molnar RE, Currie PJ. 2004. Basal Tetanurae. In: Weishampel DB, Dodson P, Osmólska H, eds. The dinosauria, 2nd edn. Berkeley, CA: University of California Press, 71–110.
4. ↑ Template:Cite journal