Open Paleo

Sinornithosaurus

Xu et al., 1999 SIEN-or-nith-o-SAWR-us

From Latin 'Sinae' (China) + Greek 'ornis' (bird) + Greek 'sauros' (lizard), meaning 'Chinese bird-lizard', reflecting its Chinese origin and bird-like features.

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

Sinornithosaurus is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period (late Barremian) of the Yixian Formation in what is now China. It was the fifth non-avian feathered dinosaur genus discovered by 1999. The original specimen was collected from the Sihetun locality of western Liaoning. It was found in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago. Additional specimens have been found in the younger Dawangzhangzi bed, dating to around 122 million years ago.

Diagnosis

  1. Ornament-like pits and ridges on anterolateral surface of antorbital fossa
  2. Posterolateral process of parietal turning sharply posteriorly
  3. Dentary bifurcated posteriorly
  4. Unserrated premaxillary teeth
  5. Supracoracoid fenestra of coracoid
  6. Manual phalanx III-1 more than twice the length of phalanx III-2
  7. Pronounced tubercle near midshaft of pubis
  8. Posterodorsal process of ischium
  9. Partially arctometatarsalian metatarsal III

Species

Sinornithosaurus millenii Xu et al., 1999

Type species

From Latin 'millennium', referring to the turn of the millennium; the species was described in 1999 and dubbed the 'millennium Chinese bird-lizard'.

Holotype
IVPP V12811 , Institute of Vertebrate Paleontology and Paleoanthropology
Material
A small dromaeosaur from Layer 6. Specimen includes articulated shoulder girdle, forelimbs, pelvic girdle, hindlimbs, and filamentous integument.
Horizon
Jianshangou Member, Yixian Formation, Barremian, Early Cretaceous , 125.8–121.4 million years ago
Locality
Sihetun, Liaoning, China

Synonyms of the genus

Name Type Reason
Jeholraptor informal Informal replacement name for Sinornithosaurus haoiana (J. haoiana); never formally published.

Notable specimens

  • “Dave”

    NGMC 91 National Geological Museum of China exceptional preservation

    Incredibly well-preserved, completely articulated microraptorian nicknamed "Dave", with feather impressions, found near Lingyuan City in the Dawangzhangzi beds. Originally left unnamed, later referred to Sinornithosaurus millenii and concluded to be a subadult of the species.

    Ji et al. (2001)Ji et al. (2002)

References

  1. Ji, Q.; Norell, M. A.; Gao, K. Q.; Ji, S. A.; Ren, D. (2001). The distribution of integumentary structures in a feathered dinosaur. Nature 410(6832): 1084-1087. ji2001a
  2. Ji, Q.; Ji, S. A.; Yuan, C. X.; Ji, X. X. (2002). Restudy on a small dromaeosaurid dinosaur with feathers over its entire body. Earth Science Frontiers 9(3): 57-63. ji2002b
  3. Xu, X.; Wang, X. L.; Wu, X. C. (1999). A dromaeosaurid dinosaur with a filamentous integument from the Yixian Formation of China. Nature 401(6750): 262-266. Springer Science and Business Media LLC. doi:10.1038/45769 xu1999a
  4. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the appearance features.

    paul2024a
  5. Wang, Y.; Olsen, P. E.; Sha, J.; Yao, X.; Liao, H.; Pan, Y.; Kinney, S.; Zhang, X.; Rao, X. (2016). Stratigraphy, correlation, depositional environments, and cyclicity of the Early Cretaceous Yixian and ?Jurassic-Cretaceous Tuchengzi formations in the Sihetun area (NE China) based on three continuous cores. Palaeogeography, Palaeoclimatology, Palaeoecology. Elsevier BV.

    Establishes Chaomidianzi as a junior synonym of the Jianshangou bed, and raises it to member rank.

    wang2016a