Open Paleo

Zhenyuanlong

Lü & Brusatte, 2015 jen-HWAHN-long

Named after Sun Zhenyuan, who discovered the specimen, combined with Chinese Pinyin lóng (龙/龍) meaning 'dragon'; thus 'Zhenyuan's dragon'

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

Zhenyuanlong is a genus of dromaeosaurid dinosaur from the Yixian Formation of Liaoning, China. It lived during the Aptian age of the early Cretaceous period, approximately 125 million years ago. It is known from a single specimen belonging to the species Zhenyuanlong suni (Chinese: 孫氏振元龍). This type specimen preserved a nearly complete skeleton that contains traces of feathers, including long tail feathers and large wings. In addition to further complicating diversity of Liaoning dromaeosaurids, this specimen provides the first direct evidence of well-developed pennaceous feathers in a large, non-flying dromaeosaur, raising the question of what function such wings would serve.

Under dispute

Zhenyuanlong is a large, short-armed Jehol dromaeosaurid whose finer placement is unresolved. Its describers recovered the Liaoning dromaeosaurids in a basal polytomy and explicitly did not recover a Zhenyuanlong + Tianyuraptor clade (Lü and Brusatte, 2015), whereas Wang and colleagues (2022, 2026) group it with Tianyuraptor and Daurlong just stemward of Eudromaeosauria. It is placed at Dromaeosauridae incertae sedis.

Diagnosis

  1. Extremely slender radius whose shaft is thinner than manual phalanx I-1
  2. Shortened metacarpal II, shorter than combined metacarpal I and phalanx I-1
  3. Six sacral vertebrae (uniquely among Liaoning dromaeosaurids)
  4. Forelimb approximately half the length of hindlimb with humerus:femur ratio less than 0.65
  5. Absence of prominent lateral tubercle at midpoint of lateral pubic shaft surface
  6. Antorbital fossa bordered ventrally by sharp rim with weak pitting on lateral surface

Species

Zhenyuanlong suni Lü & Brusatte, 2015

Type species

Named for Zhenyuan Sun, a representative of the Jinzhou Paleontological Museum who secured the specimen for study, with 'suni' being the Latin genitive of the family name.

Holotype
JPM-0008 , Jinzhou Museum of Paleontology
Material
Nearly complete skeleton with skull and lower jaws preserved; likely sub-adult based on unfused neural arches in anterior dorsals and sacrals.
Horizon
Yixian Formation, Barremian, Early Cretaceous , 125.8–121.4 million years ago
Locality
Sihedang, Lingyuan, Liaoning, China

References

  1. 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 lü2015a
  2. 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

    Recovered a Zhenyuanlong plus Tianyuraptor clade, contra earlier basal polytomy result.

    wang2022a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Illustrated by E. Viola.

    jones2026c
  4. Wang, X.; Ji, Y.; Cau, A.; Kundrát, M.; Liu, Y.; Wang, Y.; Ji, Q. (2026). Independent assembly of the flight apparatus in a non-avian dinosaur clade. Nature Communications 17(1): 10074. Springer Science and Business Media LLC. doi:10.1038/s41467-026-77804-6

    Recovered Zhenyuanlong with Daurlong and Tianyuraptor.

    wang2026b