Open Paleo

Tianyuraptor

Zheng et al., 2010 tyen-YOO-RAP-tor

Named after the Shandong Tianyu Museum of Nature where the holotype specimen is housed, combined with Latin 'raptor' meaning 'robber', referring to the action of grabbing prey

125.8–121.4 million years ago Barremian, Early Cretaceous
Early Cretaceous stages

Tianyuraptor is a genus of short-armed dromaeosaurid dinosaur ('running lizard'; a type of small dinosaur considered to be closely related to birds) that lived during the Early Cretaceous, about 122 million years ago. Its remains have been found in western Liaoning, China. It was similar to other dromaeosaurids found in Liaoning, with the exception of being somewhat more primitive. The type specimen, formally named in 2010, shows features not seen in previously known Northern Hemisphere (Laurasian) dromaeosaurids, but present in Southern Hemisphere (Gondwanan) species and early birds. Because of this, the scientists who first studied Tianyuraptor described it as a "transitional species", bridging the gap between northern and southern types of dromaeosaurid. Tianyuraptor also differs from previously known dromaeosaurids in that it possesses a relatively small furcula ("wishbone"), and unusually short forelimbs.

Under dispute

The finer placement of Tianyuraptor is unsettled. It has been recovered as a basal microraptorine (Turner and colleagues, 2012; Agnolín and Novas, 2013) and, more often in recent work, as a short-armed basal dromaeosaurid just outside Microraptorinae and stemward of Eudromaeosauria, sometimes in a clade with Zhenyuanlong and Daurlong (Lü and Brusatte, 2015; Wang and colleagues, 2022). It is placed at Dromaeosauridae incertae sedis pending resolution.

Diagnosis

  1. Middle caudal vertebrae more than twice the length of posterior dorsal vertebrae
  2. Small and extremely slender furcula
  3. Elongated hindlimb approximately three times as long as dorsal series

Species

Tianyuraptor ostromi Zheng et al., 2010

Type species

Named for John Ostrom, the paleontologist who contributed greatly to the study of dromaeosaurid fossils including Deinonychus, and who was among the earliest modern advocates for a close evolutionary relationship between birds and dinosaurs.

Holotype
STM1-3 , Shandong Tianyu Museum of Nature
Material
Nearly complete and fully articulated skeleton
Horizon
Yixian Formation, Barremian, Early Cretaceous , 125.8–121.4 million years ago
Locality
Dawangzhangzi, Liaoning, China

References

  1. Zheng, X.; Xu, X.; You, H.; Zhao, Q.; Dong, Z. (2010). A short-armed dromaeosaurid from the Jehol Group of China with implications for early dromaeosaurid evolution. Proceedings of the Royal Society B: Biological Sciences 277(1679): 211-217. The Royal Society. doi:10.1098/rspb.2009.1178 zheng2010a
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the body length and mass estimates.

    paul2024a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

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

    jones2026c
  4. Turner, A. H.; Makovicky, P. J.; Norell, M. A. (2012). A Review of Dromaeosaurid Systematics and Paravian Phylogeny. Bulletin of the American Museum of Natural History 371: 1-206. doi:10.1206/748.1

    Recovered Tianyuraptor as a basal microraptorine dromaeosaurid.

    turner2012a
  5. Lü, J.; Brusatte, S. L. (2015). A large, short-armed, winged dromaeosaurid (Dinosauria: Theropoda) from the Early Cretaceous of China and its implications for feather evolution. Scientific Reports 5(1). Springer Science and Business Media LLC. doi:10.1038/srep11775

    Described Zhenyuanlong, recovering it with Tianyuraptor and Daurlong in short-armed dromaeosaurid clade

    lü2015a
  6. Wang, X.; Cau, A.; Guo, B.; Ma, F.; Qing, G.; Liu, Y. (2022). Intestinal preservation in a birdlike dinosaur supports conservatism in digestive canal evolution among theropods. Scientific Reports 12(1). Springer Science and Business Media LLC. doi:10.1038/s41598-022-24602-x

    Described Daurlong, nesting it near Tianyuraptor closer to eudromaeosaurs than microraptorines

    wang2022a
  7. Agnolín, F. L.; Novas, F. E. (2013). Avian Ancestors. SpringerBriefs in Earth System Sciences. Springer Netherlands. doi:10.1007/978-94-007-5637-3

    Recovered Tianyuraptor as a basal microraptorine.

    agnolín2013a