Honghesaurus

Say it: HONG-heh-SORE-us

Name means: “Honghe lizard, named after the Honghe Prefecture in China where it was found”1

Ate: MeatOther sea reptilesMiddle TriassicNot technically a dinosaur

Honghesaurus was a small, lizard-like marine reptile that swam in the warm Tethys Ocean about 244 million years ago. It had an incredibly long tail, longer than any other pachypleurosaur, which helped it wiggle through the water like a fish.1

Fun fact: this sea reptile swam while dinosaurs walked on land. Everyone calls them dinos, but they were a different branch of reptiles.

Lived

244 to 243 million years ago2

Middle Triassic

Fossils found in

Luxi, Honghe, Yunnan, China1 2

Food

Meat1

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

cool stuff

Fun facts

Honghesaurus had 121 vertebrae in total, including 69 in its tail, making it the longest-tailed pachypleurosaur known.1

Its long trunk and tail gave it an advantage in maneuverability and energy efficiency for swimming with side-to-side movements.1

It had a unique feature: two fossae (small pits) in its retroarticular process, a part of the jaw, which is not seen in any other pachypleurosaur.1

Its tail was mostly laterally compressed because it had only five pairs of caudal ribs, helping it move through water efficiently.1

Honghesaurus had 29 dorsal (back) vertebrae, more than most other pachypleurosaurs, which usually have 25 or fewer.1

It lived in a semi-enclosed sea called the Yangtze Sea, part of the eastern Palaeotethys Ocean, during the Middle Triassic.1

AI-made picture of Honghesaurus — An AI-made picture of how Honghesaurus might have looked, made by a computer from what scientists know. It is a guess: the real animal may have looked different, and nobody knows its true colours.

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For dino experts

Scientific name: Honghesaurus
Named by: Xu et al. 20222
Group: Other sea reptiles
Family / clade: Pachypleurosauridae2
Classification: Sauropterygia2
Age of the rocks: 244 to 243 million years ()2
Rock formations: Guanling2
Countries: China2
Fossil records: 1 in the Paleobiology Database2
Discovery: The fossil was collected in 2021 during autumn fieldwork led by the first author, from the Guanling Formation in Luxi, Yunnan, China. It was named by Xu and colleagues in 2022.1 2
Still debated: Scientists are still debating how Honghesaurus and other pachypleurosaurs are related to each other, and whether they all came from Europe or spread from the east.1

Where the facts come from

A long-tailed marine reptile from China provides new insights into the Middle Triassic pachypleurosaur radiation | Scientific Reports (nature.com)
Honghesaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

Every fact on this page has a number that points to its source. If we got something wrong, sorry, we are dino fans, not a science journal. Tell us at [email protected] and we will fix it.

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