Organism · Dinosaurs
Yinlong downsi
Source time context (not species duration) · ≈ 201–143 Ma
Inferred life reconstruction
Yinlong downsi
Overview
Yinlong downsi was an early ceratopsian with a short frill behind its head. The low, triangular skull narrows toward the front and widens at the cheeks. Its small Late Jurassic head reveals an ancient ceratopsian form.[1][2]
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Key facts
Large oval projections occur on the cheeks, but the frill behind the head is very short. Compare it after imagining the large frill of Triceratops. Head ornament size and arrangement varied greatly even within ceratopsians.[1]
Time and place
It was a Late Jurassic dinosaur from the Shishugou Formation in present-day Xinjiang, China. The Jurassic spans approximately 200–140 million years ago. Yinlong specimens preserve the head and body of this early ceratopsian together.[1][2][3]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
The skull is low and triangular, broadest at the cheeks. A short frill projects slightly behind the head. Descriptions of short forelimbs and long, robust hind limbs invite attention to differences between the legs as well as the skull.[1][2]
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Habitat and reproduction
Differences between forelimbs and hind limbs provide clues to interpreting a body supported on two legs. The original 2006 description explained the short forelimbs and long hind limbs. It offers a body arrangement of an early relative beyond familiar impressions of ceratopsians.[2]
Fossil discovery
After the original 2006 description, a detailed skull study appeared in 2015. Reference specimen IVPP V14530 includes the skull, lower jaw, and a nearly complete postcranial skeleton. It allows head features to be compared with body structure.[1][2]
References
- Cranial anatomy of Yinlong downsi
- Xu et al. (2006) — Early ceratopsians from the Late Jurassic
- International Commission on Stratigraphy (2024) — Geological time chart
- Natural History Museum — The size of Diplodocus carnegii
- Taylor et al.2025 — History of the Carnegie Diplodocus skeleton
- Natural History Museum — Diplodocus
Research questions
Did ceratopsians have large frills from the beginning? Yinlong’s short frill and cheek projections show a different arrangement in early ceratopsian heads. Comparing several features with later relatives helps reveal change.[1]
Observation
Look for the cheek projections and short rear frill along the low skull’s profile. Then compare forelimbs and hind limbs to examine head ornaments and body organization together.[1][2]
Related organisms
Diplodocus carnegiiDinosaursSource time context (not species duration) · ≈ 201–143 MaDifferent bodies among dinosaurs
Compare the bodies and backgrounds of Yinlong downsi and Diplodocus carnegii. Yinlong downsi: an early ceratopsian with a short frill behind the head and a low, triangular skull narrowing forward and widening at the cheeks. Diplodocus carnegii: a giant plant-eating dinosaur with a long neck and an even longer tail. Its small head and slender teeth contrast with its enormous body.