Dino card No. 1542 of 2,027

Rhaeticosaurus

Say it: ray-TEE-koh-SORE-us

Name means: “Rhaetian lizard”1

Ate: MeatPlesiosaursLate TriassicNot technically a dinosaur

Rhaeticosaurus was a small, early plesiosaur that swam in the seas of the Late Triassic. It had four flippers shaped like wings and a long neck, and it used its flippers to fly through the water. This marine reptile is one of the oldest plesiosaurs ever found.2

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

Lived

206 to 201 million years ago4

Late Triassic

Fossils found in

Bonenburg clay pit in North Rhine-Westphalia, Germany2 1

Food

Meat3 2

Length

2.37 m2

estimated total length

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

as long as 5 house cats nose to tailas long as 13 bananas end to end

How big was Rhaeticosaurus compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

cool stuff

Fun facts

Rhaeticosaurus is the first plesiosaur skeleton ever found from the Triassic period, showing that plesiosaurs were already around before the Jurassic.2

Its name means 'Rhaetian lizard' because it lived during the Rhaetian age, the last stage of the Triassic.1

Rhaeticosaurus had very short lower arm and leg bones compared to its upper limb bones, with a humerus-to-radius ratio of 3.8 and a femur-to-tibia ratio of 4.3.2

The holotype skeleton was discovered in 2013 by Michael Mertens, a private collector who reported it to authorities.1

Rhaeticosaurus was a basal member of the Pliosauridae, a group of plesiosaurs with large heads and short necks.2

Its teeth had sharp ridges on the enamel, a feature that helped scientists identify it as a plesiosaur.2

AI-made picture of Rhaeticosaurus — An AI-made picture of how Rhaeticosaurus 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.

you asked

Most asked questions about Rhaeticosaurus

?How big was Rhaeticosaurus?

Rhaeticosaurus grew up to about 2.37 metres (7.8 feet) long when fully grown, based on the holotype skeleton.1 2

?Was Rhaeticosaurus a dinosaur?

No, Rhaeticosaurus was a plesiosaur, a marine reptile, not a dinosaur. It lived in the sea and used its four flippers to swim.1 2

?When did Rhaeticosaurus live?

Rhaeticosaurus lived during the Rhaetian age of the Late Triassic, about 208 to 201 million years ago. It is one of the oldest plesiosaurs ever found.1 2

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For dino experts

Scientific name: Rhaeticosaurus
Named by: Wintrich et al. 20174
Group: Plesiosaurs
Family / clade: Plesiosauria4
Classification: Plesiosauria > Sauropterygia4
Age of the rocks: 206 to 201 million years (Rhaetian)4
Rock formations: Exter4
Countries: Germany4
Fossil records: 1 in the Paleobiology Database4
Discovery: Rhaeticosaurus was named in 2017 by Wintrich and colleagues based on a partial skeleton found in 2013 in a clay pit in Germany. The fossil was discovered by Michael Mertens and later prepared for study.1 3
Still debated: Scientists are still debating exactly how many neck vertebrae Rhaeticosaurus had, but they estimate at least 37.2

Where the facts come from

Rhaeticosaurus (en.wikipedia.org)
A Triassic plesiosaurian skeleton and bone histology inform on evolution of a unique body plan (pmc.ncbi.nlm.nih.gov)
PBDB Taxon (paleobiodb.org)
Rhaeticosaurus 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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