Open Paleo

Xiaotingia

Xu et al., 2011 shyow-TIN-gee-uh

Named in honor of Chinese paleontologist Zheng Xiaoting; the generic name is derived from Xiaoting, the first part of Zheng's given name

165.3–149.2 million years ago Callovian–Kimmeridgian, Middle Jurassic–Late Jurassic
Middle Jurassic and Late Jurassic stages

Xiaotingia is a genus of paravian theropod dinosaur, possibly an anchiornithid, from Middle Jurassic or early Late Jurassic deposits of western Liaoning, China. It contains a single species, Xiaotingia zhengi.

Under dispute

Xiaotingia has been recovered in many positions: as an archaeopterygid at the base of Deinonychosauria (Xu and colleagues, 2011), as an anchiornithid on the avialan stem (Foth and Rauhut, 2017; Pei and colleagues, 2020; Xu and colleagues, 2023), as a more stemward avialan outside the anchiornithids (Foth and colleagues, 2025), as a sinovenatorine troodontid (Hartman and colleagues, 2019), and as a basal scansoriopterygid (Lefèvre and colleagues, 2017). The competing avialan and deinonychosaur hypotheses agree only on Eumaniraptora, where it is placed.

Diagnosis

  1. Maxillary posterior ramus depth at mid-length exceeds dentary depth
  2. Surangular has little lateral exposure and forms a wide, flat dorsal surface over posterior mandible
  3. Extremely large surangular foramen extends over more than 6% of total mandibular length
  4. Posterior end of mandible is blunt and dorsoventrally expanded
  5. Anteriormost caudal centra less than half as long as posterior dorsal centra
  6. Metacarpal IV more robust than metacarpals II and III
  7. Manual phalanx III-2 longer than metacarpal III

Species

Xiaotingia zhengi Xu et al., 2011

Type species

Named for paleontologist Zheng Xiaoting, together with the genus name forming a combined honorific for the same individual.

Holotype
STM 27-2 , Shandong Tianyu Museum of Nature
Material
An articulated skeleton, missing parts of the pelvis and hindlimbs and most of the caudal vertebrae, with some associated integumentary structures.
Horizon
Tiaojishan Formation, Callovian–Kimmeridgian, Middle Jurassic–Late Jurassic , 165.3–149.2 million years ago
Locality
Linglongta, Liaoning, China The holotype was bought from a dealer who could not name the quarry it came from, so Xu and colleagues (2011) place it in the formation by matching the slab's lithology against better-studied exposures, noting that Tiaojishan and Yixian shale slabs cannot be told apart on macro-sedimentary features alone.

References

  1. Xu, X.; You, H.; Du, K.; Han, F. (2011). An Archaeopteryx-like theropod from China and the origin of Avialae. Nature 475(7357): 465-470. Springer Science and Business Media LLC. doi:10.1038/nature10288 xu2011d
  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. Foth, C.; Rauhut, O. W. M. (2017). Re-evaluation of the Haarlem Archaeopteryx and the radiation of maniraptoran theropod dinosaurs. BMC Evolutionary Biology 17(1). Springer Science and Business Media LLC. doi:10.1186/s12862-017-1076-y

    Recovered Xiaotingia as an anchiornithid on the avialan stem.

    foth2017a
  4. Pei, R.; Pittman, M.; Goloboff, P. A.; Dececchi, T. A.; Habib, M. B.; Kaye, T. G.; Larsson, H. C. E.; Norell, M. A.; Brusatte, S. L.; Xu, X. (2020). Potential for Powered Flight Neared by Most Close Avialan Relatives, but Few Crossed Its Thresholds. Current Biology 30(20): 4033-4046.e8. Elsevier BV. doi:10.1016/j.cub.2020.06.105

    Recovered Xiaotingia among close avialan relatives near powered flight threshold.

    pei2020a
  5. Xu, L.; Wang, M.; Chen, R.; Dong, L.; Lin, M.; Xu, X.; Tang, J.; You, H.; Zhou, G.; Wang, L.; He, W.; Li, Y.; Zhang, C.; Zhou, Z. (2023). A new avialan theropod from an emerging Jurassic terrestrial fauna. Nature 621(7978): 336-343. Springer Science and Business Media LLC. doi:10.1038/s41586-023-06513-7

    New avialan theropod description bearing on Xiaotingia's avialan placement.

    xu2023a
  6. Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ 7: e7247. PeerJ. doi:10.7717/peerj.7247

    Recovered Xiaotingia as a sinovenatorine troodontid.

    hartman2019a
  7. Lefèvre, U.; Cau, A.; Cincotta, A.; Hu, D.; Chinsamy, A.; Escuillié, F.; Godefroit, P. (2017). A new Jurassic theropod from China documents a transitional step in the macrostructure of feathers. The Science of Nature 104(9-10). Springer Science and Business Media LLC. doi:10.1007/s00114-017-1496-y

    Recovered Xiaotingia as a basal scansoriopterygid.

    lefèvre2017a
  8. Foth, C.; van de Kamp, T.; Tischlinger, H.; Kantelis, T.; Carney, R. M.; Zuber, M.; Hamann, E.; Wallaard, J. J. W.; Lenz, N.; Rauhut, O. W. M.; Frey, E. (2025). A new Archaeopteryx from the lower Tithonian Mörnsheim Formation at Mühlheim (Late Jurassic). Fossil Record 28(1): 17-43. doi:10.3897/fr.28.131671

    Recovered Xiaotingia as a stemward avialan outside the anchiornithids.

    foth2025a