Dino card No. 1217 of 2,027

Muraenosaurus

Say it: myoo-REE-no-SORE-us

Name means: “eel lizard”1

Ate: MeatPlesiosaursMiddle Jurassic to Late JurassicNot technically a dinosaur

Muraenosaurus was a plesiosaur with a very long neck and a tiny head. It swam in warm, shallow seas during the Jurassic Period. Its name means 'eel lizard' because its neck looked like an eel's body.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

165 to 155 million years ago2

Middle Jurassic to Late Jurassic

Fossils found in

England (Oxford Clay) and France1 2

Food

Meat1

Length

5.2 m1

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 dogs nose to tailas long as 29 bananas end to end

How big was Muraenosaurus compared to YOU?

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

cool stuff

Fun facts

Muraenosaurus had 44 bones in its neck, which made up most of its 66 backbone bones before the hips.1

Its head was only about 37 centimeters (15 inches) long, very small compared to its 5.2-meter (17-foot) body.1

The first Muraenosaurus fossil was collected by Charles E. Leeds and described by Harry Seeley in 1874.1

Muraenosaurus lived in a warm, shallow sea that was less than 50 meters deep and about 20 °C (68 °F).1

Scientists think Muraenosaurus may have swallowed stones called gastroliths to help grind up food or to stop it from rolling in the water.1

Muraenosaurus was first thought to be an elasmosaur, but now scientists place it in the family Cryptoclididae.1

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

?How long was Muraenosaurus?

About 5.2 metres (17 feet) long.1

?What did Muraenosaurus eat?

It probably ate fish and cephalopods (like squid). Scientists think it may have swallowed stones to help grind up its food.1

?Could Muraenosaurus swim?

Yes, it was a marine reptile that swam in warm, shallow seas. Its long neck and flippers helped it move through the water.1

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Myth buster

Myth: Some people think Muraenosaurus was a dinosaur.

Truth: Muraenosaurus was a plesiosaur, a marine reptile that lived in the sea, not a dinosaur.1

For dino experts

Scientific name: Muraenosaurus
Named by: Seeley 18742
Group: Plesiosaurs
Family / clade: Cryptoclididae2
Classification: Plesiosauria > Sauropterygia2
Age of the rocks: 165 to 155 million years (Callovian / Oxfordian)2
Rock formations: Oxford Clay, Lajas, Argiles de Montaubert2
Countries: United Kingdom, Argentina, France2
Fossil records: 11 in the Paleobiology Database2
Also known as: Tremamesacleis (older names now counted as the same animal)2
Discovery: The first Muraenosaurus fossil was found by Charles E. Leeds in the Oxford Clay of England. Harry Seeley named it Muraenosaurus leedsii in 1874.1
Still debated: Scientists are not sure exactly how Muraenosaurus used its long neck to catch food. It may have attacked fish from below or grazed on the seafloor.1

Where the facts come from

Muraenosaurus (en.wikipedia.org)
Muraenosaurus 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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