Open Paleo

Shaochilong

Brusatte et al., 2009 Sha-chi-long

From Chinese '鲨齿' (shāchǐ) meaning 'shark tooth' and '龙' (lóng) meaning 'dragon'; meaning 'shark-toothed dragon', referring to its shark-like serrated teeth.

121.4–100.5 million years ago Aptian–Albian, Early Cretaceous
Early Cretaceous stages

Shaochilong is an extinct genus of tetanuran theropod dinosaurs from the Early Cretaceous (Barremian to Albian stages) Miaogou Formation of China, though a more restrictive suggestion from the Aptian to the Albian has been suggested based on faunal composition. It was usually described as a carcharodontosaurid, but other phylogenies have suggested a different position as a tyrannosauroid or as a member of polytomic allosauroid. The genus contains a single species, Shaochilong maortuensis, which was originally placed in the genus Chilantaisaurus as C. maortuensis, but was re-described and reclassified in 2009.

Under dispute

Shaochilong maortuensis is recovered as a derived carcharodontosaurid, the first from Asia (Brusatte and colleagues, 2009; Carrano and colleagues, 2012; Novas and colleagues, 2013), but the two most recent analyses instead place it within Coelurosauria: Kellermann and colleagues (2025) recover it as a tyrannosauroid in all their analyses (rebutting the proposed carcharodontosaurid characters), and Rauhut and colleagues (2024) recover it as a coelurosaur. Carcharodontosauridae (Allosauroidea) and Tyrannosauroidea (Coelurosauria) are the two branches of Avetheropoda, the least-inclusive clade all these hypotheses accept.

Diagnosis

  1. Maxillary antorbital fossa reduced in extent and nearly absent
  2. Paradental groove on medial surface of maxilla absent
  3. Deep, dorsoventrally oriented grooves located dorsally on maxillary interdental plates
  4. Pneumatic recess penetrates to posterior end of nasal
  5. Sagittal crest on frontal
  6. Large pneumatic foramen at anterodorsal corner of dorsal tympanic recess of prootic
  7. Frontal sagittal crest rises from broad dorsal surface unlike in coelurosaurs and abelisaurids

Species

Shaochilong maortuensis Brusatte et al., 2009

Type species

Named for the Maortu locality in Inner Mongolia, China, where the fossil material was discovered.

Holotype
IVPP V2885.1, IVPP V2885.2, IVPP V2885.3, IVPP V2885.4, IVPP V2885.5, IVPP V2885.6, IVPP V2885.7 , Institute of Vertebrate Paleontology and Paleoanthropology
Material
Associated cranial and axial elements of a single individual, including braincase, frontals, parietals, right nasal, right maxilla, quadrates, axis, and six caudal vertebrae.
Horizon
Miaogou Formation, Aptian–Albian, Early Cretaceous , 121.4–100.5 million years ago
Locality
Maortu, Inner Mongolia, China

Synonyms of the genus

Name Type Reason
Alashansaurus nomen ex dissertatione Informally named by Chure in 2000; the specimen was later formally described as Shaochilong.

References

  1. Hao, M.; Li, Z.; Wang, Z.; Wang, S.; Ma, F.; Qinggele; Logan King, J.; Pei, R.; Zhao, Q.; Xu, X. (2024). A new oviraptorosaur from the Lower Cretaceous Miaogou Formation of western Inner Mongolia, China. Cretaceous Research 167(78): 106023. Elsevier BV. doi:10.1016/j.cretres.2024.106023

    Dates the Miaogou Formation at the Maortu locality Aptian-Albian, and lists Shaochilong among its three dinosaur species.

    hao2024a
  2. Brusatte, S. L.; Benson, R. B. J.; Chure, D. J.; Xu, X.; Sullivan, C.; Hone, D. W. E. (2009). The first definitive carcharodontosaurid (Dinosauria: Theropoda) from Asia and the delayed ascent of tyrannosaurids. Naturwissenschaften 96(9): 1051-1058. Springer Science and Business Media LLC. doi:10.1007/s00114-009-0565-2

    Redescription; recovered Shaochilong as a derived carcharodontosaurid, the first from Asia, rejecting earlier tyrannosauroid/coelurosaur readings.

    brusatte2009a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026c
  4. 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

    Recovered Shaochilong as a derived carcharodontosaurid.

    carrano2012a
  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 Shaochilong as a coelurosaur, not a carcharodontosaurid.

    rauhut2024a
  6. Kellermann, M.; Cuesta, E.; Rauhut, O. W. M. (2025). Re-evaluation of the Bahariya Formation carcharodontosaurid (Dinosauria: Theropoda) and its implications for allosauroid phylogeny. PLOS ONE 20(1): e0311096. Public Library of Science (PLoS). doi:10.1371/journal.pone.0311096

    Recovered Shaochilong within Tyrannosauroidea, not Carcharodontosauridae.

    kellermann2025a
  7. Novas, F. E.; Agnolín, F. L.; Ezcurra, M. D.; Porfiri, J.; Canale, J. I. (2013). Evolution of the carnivorous dinosaurs during the Cretaceous: The evidence from Patagonia. Cretaceous Research 45: 174-215.

    Recovered Shaochilong as the sister of Carcharodontosaurinae.

    novas2013a