Ceresiosaurus

Say it: SEH-ree-zee-oh-SORE-us

Name means: “lizard of Ceresio (Lake Lugano)”1

Ate: MeatOther sea reptilesMiddle TriassicNot technically a dinosaur

Ceresiosaurus was a long, swimming reptile that lived in warm, shallow seas during the Middle Triassic, about 242 million years ago. It was not a dinosaur, but a relative of plesiosaurs, with flippers like paddles and a very short skull. It grew up to 3 metres (9.8 feet) long, making it one of the biggest animals in its lagoon home.1 3

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

Lived

241 to 237 million years ago3

Middle Triassic

Fossils found in

Monte San Giorgio, Switzerland and Italy1 3

Food

Meat1

Length

up to 3 m1

snout-tail length

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

as long as 1.5 bicycles in a rowas long as 17 bananas end to end

How big was Ceresiosaurus compared to YOU?

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

cool stuff

Fun facts

Ceresiosaurus had the shortest skull of any known nothosaur, making it look more like a plesiosaur.1

Its flippers were very long, with many extra finger bones, just like later plesiosaurs.1

Scientists think Ceresiosaurus swam like a penguin, using its powerful tail and hips to push through the water instead of wiggling its body.1

There are two species: Ceresiosaurus calcagnii and Ceresiosaurus lanzi, which lived at slightly different times.1

The older species, C. calcagnii, had heavy, dense bones in its ribs, which helped it stay underwater like a diver's weight belt.2

The younger species, C. lanzi, had lighter bones and was probably a faster swimmer in open water.2

Ceresiosaurus lived in a warm, subtropical lagoon with many other small marine reptiles.1

AI-made picture of Ceresiosaurus — An AI-made picture of how Ceresiosaurus 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 Ceresiosaurus

?How did Ceresiosaurus swim?

It probably swam like a penguin, using its powerful tail and hips to push through the water instead of wiggling its body.1

?Was Ceresiosaurus a dinosaur?

No, it was a marine reptile called a sauropterygian, and a relative of plesiosaurs, not a dinosaur.1

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For dino experts

Scientific name: Ceresiosaurus
Named by: Peyer 19313
Group: Other sea reptiles
Family / clade: Nothosauridae3
Classification: Sauropterygia3
Age of the rocks: 241 to 237 million years (Ladinian)3
Rock formations: Cassina, Meride, Muschelkalk3
Countries: Switzerland, Spain3
Fossil records: 12 in the Paleobiology Database3
Discovery: Ceresiosaurus was named by Bernhard Peyer in 1931, based on fossils found at Monte San Giorgio, Switzerland. The name means 'lizard of Ceresio', after Lake Lugano.1 3
Still debated: Scientists still debate whether Ceresiosaurus is really a separate genus or just a species of Lariosaurus.1

Where the facts come from

Ceresiosaurus (en.wikipedia.org)
zora.uzh.ch (zora.uzh.ch)
Ceresiosaurus 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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