Chensaurus
Chensaurus was an early ichthyosaur, a marine reptile that swam in the seas during the Triassic Period. It had a long, narrow body and a small tail fin, and it moved through the water like an eel. It was not a dinosaur, but a distant relative of lizards and snakes.1
When did it live?
How big was it?
Fun facts
Chensaurus is one of the oldest known ichthyosaurs, living about 250 million years ago.3
It had a long, narrow body and a small caudal fin, which suggests it swam like an eel, not like a fish.1
Chensaurus had a high number of vertebrae in its body, which helped it move in a wavy, eel-like way.1
It is considered an evolutionary intermediate between land reptiles and later, more fish-like ichthyosaurs.1
The name Chensaurus was given in 1991, but some scientists think it is the same as another ichthyosaur called Chaohusaurus.2

Myth buster
Myth: Chensaurus was a dinosaur.
Truth: Chensaurus was an ichthyosaur, a marine reptile, not a dinosaur. Ichthyosaurs lived in the sea and were more closely related to lizards and snakes.1
For dino experts
- Scientific name
- Chensaurus
- Named by
- Mazin Suteethora et al. 19913
- Group
- Ichthyosaurs
- Family / clade
- Grippiidae3
- Classification
- Ichthyosauria > Ichthyosauromorpha3
- Age of the rocks
- 251 to 237 million years ()3
- Countries
- China3
- Fossil records
- 9 in the Paleobiology Database3
- Discovery
- Chensaurus was named by Mazin Suteethora and colleagues in 1991. The fossils were found in Anhui Province, China.33
- Still debated
- Scientists debate whether Chensaurus is a separate genus or just a younger name for Chaohusaurus, because the fossils are very similar.2
Where the facts come from
- Eel-like swimming in the earliest ichthyosaurs - ADS (ui.adsabs.harvard.edu)
- PBDB Taxon (paleobiodb.org)
- Chensaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.
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