Huaxiagnathus
"Chinese jaw"
- Lived
- 126 to 120 million years ago, Early Cretaceous
- Diet
- Carnivore
- Group
- Theropods, Compsognathidae
- Found in
- China
- Named by
- Hwang et al. 2004
Where its fossils were found
The evidence
Today
125 million years ago
Habitat
Forests and lakes in the Yixian Formation of China, shared with Sinosauropteryx, Psittacosaurus and Beipiaosaurus.
Field notes
About Huaxiagnathus
What it was like
Huaxiagnathus was a small, two-legged predator known from a nearly complete skeleton. It was larger than its relative Sinosauropteryx, with strong hands and long fingers suited to grabbing prey.
Its world
It lived about 126 to 120 million years ago, in the Early Cretaceous, in what is now China. Its bones come from the Yixian Formation, a land of forests and lakes shared with Sinosauropteryx, the small horned Psittacosaurus and the long-clawed Beipiaosaurus.
How it was found
Hwang and colleagues named it in 2004.
Field gallery
More views of Huaxiagnathus
Scenes reconstructed from the available fossil evidence.
1 of 3
Lived alongside
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Huaxiagnathus.
The evidence
The science behind Huaxiagnathus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- A nearly complete skeleton preserves the skull, backbone and limbs, with only the end of the tail missing.
- The hands have strongly curved claws, with a large claw on both the thumb and the next finger.
- The outer finger is shorter and slimmer, with a smaller claw.
Borrowed from relatives
- Most of the body is known from its own bones; the missing tail tip is restored by comparison with other early coelurosaurs such as Sinosauropteryx.
Still unknown
- Whether Sinotyrannus represents the adult form of Huaxiagnathus.
- Its exact place in the theropod family tree.
- Its skin covering and color.
Discovery timeline
- 2004Named itHwang et al.
- 2025Growing upCau & Paterna
Key papers
The research behind what we know of Huaxiagnathus
Named it
Described a nearly complete skeleton with strong grasping hands and identified Huaxiagnathus as an early member of the compsognathid family.
A large Compsognathid from the early cretaceous Yixian formation of China. Journal of Systematic Palaeontology 2: 13-30
Read the paper : A large Compsognathid from the early cretaceous Yixian formation of China (opens in a new tab)Growing up
Proposed that Sinotyrannus is the mature form of Huaxiagnathus, based on shared hip anatomy and differences consistent with growth.
Beyond the Stromer’s Riddle: the impact of lumping and splitting hypotheses on the systematics of the giant predatory dinosaurs from northern Africa. Italian Journal of Geosciences 144: 162-185
Read the paper : Beyond the Stromer’s Riddle: the impact of lumping and splitting hypotheses on the systematics of the giant predatory dinosaurs from northern Africa (opens in a new tab)
Close relatives
Other members of Compsognathidae
Sources: Wikidata