Dino card No. 0622 of 2,027

Eremiasaurus

Say it: eh-REM-ee-ah-SORE-us

Name means: “desert lizard”1

Ate: MeatMosasaursLate CretaceousNot technically a dinosaur

Eremiasaurus was a marine reptile that swam in warm seas during the time of the dinosaurs. It was a mosasaur, not a dinosaur, and it lived about 70 to 66 million years ago. This predator had a streamlined body and a long tail to help it zoom through the water.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

72 to 66 million years ago2

Late Cretaceous

Fossils found in

Morocco, especially the Ouled Abdoun Basin near Oued Zem1

Food

Meat1 2

Length

4.5 to 5 m1

estimates based on two skeletons

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

as long as 3 bicycles in a rowas long as 28 bananas end to end

How big was Eremiasaurus compared to YOU?

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cool stuff

Fun facts

Eremiasaurus had very different-shaped teeth in its jaws, a rare trait for mosasaurs. Its species name heterodontus means 'different teeth'.1

The first fossils of Eremiasaurus were teeth found in Morocco in 1952. Scientists at first thought they belonged to another mosasaur called Mosasaurus.1

Eremiasaurus was named in 2012 from two nearly complete skeletons. One skeleton was found by a scientist, and the other came from a commercial fossil collector.1

This mosasaur had a tail that bent downward and a fan of bones in its tail, which helped it swim fast. Its tail was similar to the fast-swimming mosasaur Plotosaurus.1

Eremiasaurus lived in a warm, shallow sea called the Mediterranean Tethys. Many other mosasaurs and fish lived there too.1

Scientists think Eremiasaurus ate different food than its larger mosasaur neighbors, like Thalassotitan and Prognathodon. This helped them avoid competing for the same prey.1

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

?How big was Eremiasaurus?

About 5 metres (16 feet) long, which is a bit shorter than a minibus.1

?What did Eremiasaurus eat?

Nobody knows for sure. Its different-shaped teeth make it unclear what prey it ate.1

?Could Eremiasaurus swim fast?

Yes. Its tail bones suggest it was a high-speed pursuit predator, built for fast swimming.1

?Where did Eremiasaurus live?

It lived in a warm, shallow sea called the Mediterranean Tethys, near what is now Morocco.1

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For dino experts

Scientific name: Eremiasaurus
Named by: LeBlanc et al. 20122
Group: Mosasaurs
Family / clade: Mosasauridae2
Classification: Mosasauroidea2
Age of the rocks: 72 to 66 million years (Maastrichtian)2
Rock formations: Phosphates, Couche III2
Countries: Morocco2
Fossil records: 7 in the Paleobiology Database2
Discovery: Eremiasaurus was named in 2012 by paleontologists Aaron LeBlanc, Michael Caldwell, and Nathalie Bardet. They described it from two skeletons found in the phosphate mines of the Ouled Abdoun Basin in Morocco.1
Still debated: Scientists are not sure exactly what Eremiasaurus ate. Its unusual teeth make it hard to guess its favorite prey.1

Where the facts come from

Eremiasaurus (en.wikipedia.org)
Eremiasaurus 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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