Open Paleo

Yuanmouraptor

Zou et al., 2025 yoo-AHN-moo-RAP-tuh

From 'Yuanmou' (Yuanmou County, Yunnan Province, China, the type locality) and Latin 'raptor' (robber).

174.7–168.2 million years ago Aalenian–Bajocian, Middle Jurassic
Middle Jurassic stages

Yuanmouraptor is an extinct genus of basal metriacanthosaurid theropod from the early Middle Jurassic (Aalenian-Bajocian) Zhanghe Formation at Xiabanjing Village, Yuanmou County, Chuxiong Yi Autonomous Prefecture, Yunnan Province, China. The single species, Yuanmouraptor jinshajiangensis, is known from a near-complete skull with mandible (reconstructed length ~60 cm) articulated with 10 cervical vertebrae and the first dorsal (LFGT-ZLJ0115). Zou and colleagues (2025) recover Yuanmouraptor as the most basal-branching member of Metriacanthosauridae in their equal-weights phylogenetic analysis.

Diagnosis

  1. Anterior process of postorbital sheet-shaped with depth remaining consistent throughout its length.
  2. Ventral ramus of postorbital bearing a laterally twisted trough running along its lateral surface.
  3. Strongly posteriorly elongated epipophyses on anterior cervical vertebrae.
  4. Strongly ventromedially excavated pneumatic foramen on the third cervical vertebra.
  5. Posterior cervical vertebrae with sheet-shaped and subrectangular neural spines.

Species

Yuanmouraptor jinshajiangensis Zou et al., 2025

Type species

From 'Jinshajiang' (the Jinsha River, the middle reach of the Yangtze) and Latin '-ensis' (of); the type locality lies on the river's north bank in Yuanmou County.

Holotype
LFGT-ZLJ0115 , Lufeng World Dinosaur Valley
Material
Nearly complete skull with mandible and 11 articulated anterior vertebrae comprising 10 cervical vertebrae and the first dorsal vertebra.
Horizon
Zhanghe Formation, Aalenian–Bajocian, Middle Jurassic , 174.7–168.2 million years ago
Locality
Xiabanjing Village, Jiangyi Township, Yunnan, China

References

  1. Zou, Y.; Chen, L.; Wang, T.; Wang, G. F.; Zhang, W. G.; Zhang, X. Q.; Wang, Z. J.; Wu, X. C.; You, H. L. (2025). A new metriacanthosaurid theropod dinosaur from the Middle Jurassic of Yunnan Province, China. PeerJ 13: e19218. PeerJ. doi:10.7717/peerj.19218

    Erects Yuanmouraptor on a near-complete skull and articulated anterior cervical column; recovered as the most basal-branching metriacanthosaurid in equal-weights phylogenetic analysis.

    zou2025a