Open Paleo

Kelmayisaurus

Dong, 1973 kuhl-MAH-yi-SAWR-us

Named for Karamay (Kelmay in Uyghur), the petroleum-producing city in Xinjiang, China near where it was found, combined with Greek 'sauros' meaning 'lizard', hence 'Karamay lizard'.

137.1–100.5 million years ago Valanginian–Albian, Early Cretaceous
Early Cretaceous stages

Kelmayisaurus is an extinct genus of carcharodontosaurian theropod dinosaur from the Early Cretaceous. It was roughly 10-12 meters (33-39 feet) long and its name refers to the petroleum-producing city of Karamay in the Xinjiang province of western China near where it was found.

Under dispute

Kelmayisaurus petrolicus, once considered a nomen dubium, was revalidated as a basal carcharodontosaurid on the basis of a single autapomorphy (Brusatte and colleagues, 2012); its fragmentary material yields weak, unstable support, and Kellermann and colleagues (2025) recover it in varying positions across Allosauroidea. It is placed conservatively at Carcharodontosauridae incertae sedis.

Diagnosis

  1. Deeply inset, dorsally concave groove on the anterior part of the lateral surface of the dentary
  2. Maxillary interdental plates more than twice as tall dorsoventrally as they are broad anteroposteriorly
  3. Prominent anterior process of the maxilla
  4. No anteroventral chin-like process on the dentary

Species

Kelmayisaurus petrolicus Dong, 1973

Type species

From Latin 'petrolicus' meaning 'of petroleum', referring to the petroleum-producing city of Karamay near the discovery locality in Xinjiang, China.

Holotype
IVPP V4022 , Institute of Vertebrate Paleontology and Paleoanthropology
Material
Partial skull
Horizon
Lianmuqin Formation, Valanginian–Albian, Early Cretaceous , 137.1–100.5 million years ago
Locality
field locality 64043-6, Xinjiang, China

References

  1. Dong, Z. (1973). [Dinosaurs from Wuerho]. Reports of Paleontological Expedition to Sinkiang (II): Pterosaurian Fauna from Wuerho, Sinkiang. Memoirs of the Institute of Vertebrate Paleontology and Paleoanthropology, Academia Sinica 11: 45-52. dong1973a
  2. Xu, X.; Choiniere, J.; Tan, Q.; Benson, R. B. J.; Clark, J.; Sullivan, C.; Zhao, Q.; Han, F.; Ma, Q.; He, Y.; Wang, S.; Xing, H.; Tan, L. (2018). Two Early Cretaceous Fossils Document Transitional Stages in Alvarezsaurian Dinosaur Evolution. Current Biology 28(17): 2853-2860.e3. Elsevier BV. doi:10.1016/j.cub.2018.07.057

    Gives "(Barremian-Aptian?)" only for the Xiyunykus horizon at Wucaiwan, not for the Lianmuqin at Wuerho.

    xu2018c
  3. 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

    Re-evaluated Bahariya carcharodontosaurid material, finding unstable allosauroid position for Kelmayisaurus.

    kellermann2025a
  4. Brusatte, S. L.; Benson, R. B. J.; Xu, X. (2012). A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China. Acta Palaeontologica Polonica 57(1): 65-72. doi:10.4202/app.2010.0125

    Revalidated Kelmayisaurus as a basal carcharodontosaurid, on one dentary autapomorphy and a unique combination of maxillary and dentary characters. Dates the Lianmuqin Formation "?Valanginian-Albian".

    brusatte2012c