Gigantspinosaurus sichuanensis was an early stegosaur that lived during the mid-Jurassic, about 166 million years ago, in what is now southwestern China.
Around 4.5m long (~14'9"), it had relatively small back plates and a pair of enormous shoulder spikes. It's unclear exactly how the shoulder spines were positioned in life, but based on how they were found articulated in a fairly complete skeleton they seem to have swept sideways and backwards, protecting Gigantspinosaurus' flanks.
Skin impressions show a mosaic of polygonal scales with scattered "rosettes" made up of larger scales surrounded by a ring of smaller scales, with a rough ridged surface texture that may have reduced light glare – suggesting an overall more matte appearance rather than glossy.
The thigh bones of one specimen are pathological, showing evidence that these dinosaurs sometimes suffered from bone tumors.
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References:
Hao, Baoqiao, et al. "Redescription of Gigantspinosaurus sichuanensis (Dinosauria, Stegosauria) from the Late Jurassic of Sichuan, Southwestern China." Acta Geologica Sinica‐English Edition 92.2 (2018): 431-441. https://doi.org/10.1111/1755-6724.13535
Hao, Baoqiao, et al. "Femoral osteopathy in Gigantspinosaurus sichuanensis (Dinosauria: Stegosauria) from the Late Jurassic of Sichuan Basin, Southwestern China." Historical Biology 32.8 (2020): 1028-1035. https://doi.org/10.1080/08912963.2018.1561673
Wikipedia contributors. “Gigantspinosaurus” Wikipedia, 04 Aug. 2025, https://en.wikipedia.org/wiki/Gigantspinosaurus
Xing, Lida, Peng, G.-Z., and Shu, C.-K. "Stegosaurian skin impressions from the Upper Jurassic Shangshaximiao Formation, Zigong, Sichuan, China: A new observation." Geological Bulletin of China 27.7 (2008): 1049-1053. http://www.xinglida.net/pdf/XING_et_al_2008_Stegosaurian_skin.pdf
Zhou, Yuxuan, et al. "Zircon geochronology of the new dinosaur fauna in the Middle Jurassic lower Shaximiao Formation in Chongqing, SW China." Palaeogeography, Palaeoclimatology, Palaeoecology 592 (2022): 110894. https://doi.org/10.1016/j.palaeo.2022.110894
Somehow neglected to share this Stegosaurus bas-relief project here, when I began in December 2024, so now that I'm starting it over I may as well share both versions. The more finished-looking one, in soft clay, is now unworkable because its plastic base has warped too badly, and so the new, slightly larger air-hardening clay version is mounted on a pane of glass instead. Thankfully, water restores this Paperclay's pliability, so I'll be able to texture and reshape this project even as it dries.
More detail and context in the image descriptions.
Did you know? Humans are closer to T. rex in the geological timeline than T. rex was to Stegosaurus.
What kind of dinosaur is Stegosaurus? And what were its plates used for? Learn more about Stegosaurus and its fellow stegosaurs with Museum paleontologist Roger Benson! Explore what we’ve learned from fossils like the recently discovered Apex—the most complete Stegosaurus ever found. These specimens can give us clues into the dinosaurs’ diet, lifespan, size, and natural history.
