Tuojiangosaurus (meaning "Tuo River lizard") is a genus of stegosaurid dinosaur from the Late Jurassic Period, recovered from the Upper Shaximiao Formation of what is now Sichuan Province in China.
Description[]
Physically similar to the North American Stegosaurus, Tuojiangosaurus is the best understood of the Chinese stegosaurids.[1] It was around 7 metres (23 ft) long and 2 metres (6.6 ft) high, with a postulated weight of around 4 tonnes (4.4 short tons).
Like Kentrosaurus, Tuojiangosaurus had two rows of pointed plates along the spine, which became taller over the hip region. It also had two outward-pointing spikes on each side of the end of the tail, angled at approximately 45 degrees to the vertical. In stegosaurids, this spike arrangement has become affectionately known as the "thagomizer". It also had the typical narrow head, bulky body, and low teeth of other stegosaurids.[1]
Because it lacked the tall spines for muscle attachment found on the vertebrae of Stegosaurus, it was probably unable to rear up on its hind legs like that animal. This suggests that it would have eaten low-lying, ground vegetation.
Discovery[]
The type and only species, T. multispinus, was named in 1977 (exactly a hundred years after Stegosaurus) on the strength of two specimens, one over half complete.
A mounted skeleton of Tuojiangosaurus multispinus is on display at the Municipal Museum of Chongqing. In addition, a mounted cast is on display at the Natural History Museum, in London.
Classification[]
Tuojiangosaurus was by Dong placed in Stegosauridae in 1977, more precisely in the Stegosaurinae.[1] In 2004, a cladistic analysis by Galton recovered Tuojiangosaurus in a rather derived position, as a sister species of Chialingosaurus.[2] An analysis by Octávio Mateus, Maidment, and Nicolai Christiansen, published in 2009, found that Tuojiangosaurus fell outside of Stegosauridae, though its exact position in Stegosauria (either as an early branching member of the group or a later branching species closer to stegosaurids) was uncertain due to the relatively fragmentary nature of the remains.[3] A more comprehensive analysis by Raven and Maidment in 2017 found that it grouped with Huayangosaurus and its relatives.[4]
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<ref>tag; no text was provided for refs namedGalton2004 - ^ Mateus, Maidment and Christiansen (2009). "A new long-necked ‘sauropod-mimic’ stegosaur and the evolution of the plated dinosaurs", Proc Biol Sci. 2009 May 22; 276(1663): 1815–1821.
- ^ Raven, T.j.; Maidment, S.C.R. (2017). "A new phylogeny of Stegosauria (Dinosauria, Ornithischia)". Palaeontology 2017 (3): 401–408. doi:. http://eprints.brighton.ac.uk/16844/1/Raven%26Maidment_AcceptedPreprint.pdf.