Open Paleo

Shidaisaurus

Wu et al., 2009 shih-DYE-SAWR-us

Named for the Jin-Shidai ('Golden Age') Company, which oversaw excavation and inspection of the Jurassic World Park near the discovery site, combined with Greek 'sauros' meaning 'lizard'.

170.9–168.2 million years ago Bajocian, Middle Jurassic
Middle Jurassic stages

Shidaisaurus is a genus of metriacanthosaurid dinosaur. Its fossil was found in early Middle Jurassic-age rocks of the Chuanjie Formation in Yunnan, China. It is known from a partial skeleton, holotype DML-LCA 9701-IV, found at the bottom of an assemblage of nine dinosaur individuals, lacking most of the tail vertebrae, ribs, pectoral girdle, and limb bones. Shidaisaurus was described in 2009 by Wu and colleagues. The type species is Shidaisaurus jinae. Generic name and specific name in combination refer to the Jin-Shidai ("Golden Age") Company that oversaw excavation and inspection of the Jurassic World Park near the site.

Under dispute

Shidaisaurus jinae is a basal metriacanthosaurid. Carrano, Benson and Sampson (2012) recover it as a basal metriacanthosaurine once unstable taxa are pruned, but in an unresolved basal position within Metriacanthosauridae in their full analysis, and Zou and colleagues (2025) and Rauhut and colleagues (2024) place it outside Metriacanthosaurinae. It is placed conservatively at Metriacanthosauridae incertae sedis.

Diagnosis

  1. Supraoccipital excluded from foramen magnum by exoccipitals
  2. Paroccipital process downturned approximately 110° from vertical
  3. Axis with large, sharply pointed epipophysis and thin lamina between epipophysis and neural spine broader than in other theropods
  4. Anteroventral to dorsoposterior pubic length nearly equal to height of iliac blade
  5. Lacks ventral notch distal to obturator process on ischium
  6. Ischium relatively long (more than 96% the length of pubis)
  7. Absence of pleurocoels in axis and anterior dorsal vertebrae

Species

Shidaisaurus jinae Wu et al., 2009

Type species

Named for the Jin-Shidai ('Golden Age') Company, which oversaw excavation and inspection of the Jurassic World Park near the discovery site in Yunnan, China.

Holotype
LDM-LCA 9701-IV , Lufeng Dinosaur Museum
Material
Partial skeleton lacking most caudal vertebrae, ribs, pectoral girdles, and limb bones
Horizon
Chuanjie Formation, Bajocian, Middle Jurassic , 170.9–168.2 million years ago
Locality
Quarry 1, Laochangqing, Yunnan, China

References

  1. Wu, X.; Currie, P. J.; Dong, Z.; Pan, S.; Wang, T. (2009). A New Theropod Dinosaur from the Middle Jurassic of Lufeng, Yunnan, China. Acta Geologica Sinica (English Edition) 83(1): 9-24. Wiley. doi:10.1111/j.1755-6724.2009.00002.x wu2009a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026c
  3. Carrano, M. T.; Benson, R. B. J.; Sampson, S. D. (2012). The phylogeny of Tetanurae (Dinosauria: Theropoda). Journal of Systematic Palaeontology 10(2): 211-300. Informa UK Limited. doi:10.1080/14772019.2011.630927

    Tetanurae phylogeny allowing Shidaisaurus's possible Metriacanthosaurinae placement.

    carrano2012a
  4. Zou, Y.; Chen, L.; Wang, T.; Wang, G. F.; Zhang, W. G.; Zhang, X. Q.; Wang, Z. J.; Wu, X. C.; You, H. L. (2025). A new metriacanthosaurid theropod dinosaur from the Middle Jurassic of Yunnan Province, China. PeerJ 13: e19218. PeerJ. doi:10.7717/peerj.19218

    New metriacanthosaurid description bearing on Shidaisaurus's basal position.

    zou2025a
  5. Rauhut, O. W. M.; Bakirov, A. A.; Wings, O.; Fernandes, A. E.; Hübner, T. R. (2024). A new theropod dinosaur from the Callovian Balabansai Formation of Kyrgyzstan. Zoological Journal of the Linnean Society 201(4). Oxford University Press (OUP). doi:10.1093/zoolinnean/zlae090

    Recovered Shidaisaurus as the earliest-branching metriacanthosaurid.

    rauhut2024a