Open Paleo

Yinlong

Xu et al., 2006 yin-long

From Mandarin Chinese yin (隱) meaning 'hidden' and long (龍) meaning 'dragon'; translates as 'hidden dragon,' a reference to the film Crouching Tiger, Hidden Dragon filmed near the discovery site in Xinjiang

165.3–154.8 million years ago Callovian–Oxfordian, Middle Jurassic–Late Jurassic
Middle Jurassic and Late Jurassic stages

Yinlong is a genus of basal ceratopsian dinosaur from the Late Jurassic Period of China. By far the earliest known ceratopsian, it was a small, primarily bipedal herbivore.

Diagnosis

  1. Distinct fossa along the midline of the frontals
  2. Trapezoidal quadratojugal longer than deep
  3. Sharp ridges and grooves on the anterior surface of the proximal half of the paroccipital process
  4. Long basipterygoid process oriented posteroventrally
  5. Slit-like carotid canal laterally bordered by a lamina
  6. Prominent tubercle on the posteroventral surangular and vertical wear facet with a basal shelf on premaxillary teeth

Species

Yinlong downsi Xu et al., 2006

Type species

Named for William Randall Downs III, an American vertebrate paleontologist who frequently participated in paleontological expeditions to China and died the year before the holotype was discovered.

Holotype
IVPP V14530 , Institute of Vertebrate Paleontology and Paleoanthropology
Material
A nearly complete skeleton missing only the distal tail.
Horizon
upper Shishugou Formation, Callovian–Oxfordian, Middle Jurassic–Late Jurassic , 165.3–154.8 million years ago
Locality
Wucaiwan, Xinjiang, China Xu and colleagues (2006) place the holotype in the upper Shishugou and correlate it with the Oxfordian. Han and colleagues (2015) put the same part of the formation between tuffs dated 162.2 and 159.7 Ma, which on the ICS chart v2024/12 straddle the base of the Oxfordian.

References

  1. Xu, X.; Forster, C. A.; Clark, J. M.; Mo, J. (2006). A basal ceratopsian with transitional features from the Late Jurassic of northwestern China. Proceedings of the Royal Society B: Biological Sciences 273(1598): 2135-2140. The Royal Society. doi:10.1098/rspb.2006.3566 xu2006a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

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

    jones2026a
  3. Han, F.; Forster, C. A.; Clark, J. M.; Xu, X. (2015). A new taxon of basal ceratopsian from China and the early evolution of Ceratopsia. PLOS ONE 10(12): e0143369. Public Library of Science (PLoS). doi:10.1371/journal.pone.0143369

    Places Hualianceratops in the same part of the Shishugou as Yinlong, between tuffs dated 162.2 and 159.7 Ma.

    han2015a