Chungkingosaurus

*Chungkingosaurus jiangbeiensis*

***Chungkingosaurus*** is a Stegosaur from late Jurassic China. It is about 11.5 feet long (3.5 meters) and is a fairly small Stegosaur.

## Description

The *Chungkingosaurus jiangbeiensis* holotype was one of the smallest stegosaurs with a length of less than four metres (about thirteen feet), even though it was apparently an adult, judging by the ossification of the sacrum. *Chungkingosaurus* sp. 1 was estimated at five metres; *Chungkingosaurus* sp. 2 was seen as longer than five metres. *Chungkingosaurus* strongly resembled *Tuojiangosaurus*, found in the same formation, in many anatomical details. *Chungkingosaurus* was different in its smaller size, deeper snout and front lower jaws (resulting in a relatively high and narrow skull), and non-overlapping teeth with less pronounced denticles.

*Chungkingosaurus* probably possessed two rows of plates and spikes on its back, which were arranged in pairs, but the total number is unknown. A skeleton model in the Chongqing Municipal museum shows fourteen pairs of plates. This model also has two pairs of tail spikes. The plates of *Chungkingosaurus* have a thickened middle section, as if they were modified spikes. The plates resemble those of *Tuojiangosaurus*. The form of the thagomizer, the tail end spikes used as a defensive weapon, is only known from specimen CV 00208. It preserves two pairs of obliquely vertical, rather stout, spikes. A third pair to the front of these was originally present but lost during the excavation. A unique feature is the presence of an additional pair at the very tail end, consisting of long thin spikes oriented almost horizontally and obliquely to the sides and rear in top view. Paul described this kind of thagomizer as a "pin-cushion array". The thagomizer of *Tuojiangosaurus* is not known from articulated remains.

## Discovery and species

The type species, *Chungkingosaurus jiangbeiensis*, was found near Chongqing, China. in 1977 and described by Dong Zhiming, Zhou Shiwu, and Chang Yihong in 1983. There were many stegosaurs found in China in 1977 (the year *Chungkingosaurus* was found), but *Chungkingosaurus* was the smallest of these.

## Paleobiology

Like all stegosaurs, it was a herbivore. *Chungkingosaurus* had spiny plates on its back, which were arranged in pairs, but the total number is unknown. A specimen in the Chongqing Municipal museum is represented as having 14 pairs of plates. This specimen also had two pairs of tail spikes.

*Chungkingosaurus* is thought to have coexisted with large plant-eaters and stegosaurids such as *Chialingosaurus*, *Tuojiangosaurus*, *Mamenchisaurus*, and *Omeisaurus*. It may have also faced being a meal of predators such as the theropods *Yangchuanosaurus* and *Szechuanosaurus*.

## Dinosaur Earth Description

Chungkingosaurus was a moderate sized dinosaur from the same family as Stegosaurus. It is known from only a single individual, so not a whole lot is understood about this creature. The plates along its back were spike like, and it had 4 or 5 pair of tail spikes, pointed to the rear of the animal. Three additional specimens have been tentatively referred to this genus. It is considered a primitive form of the stegosaur.