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Mollesaurus

Say it: mol-ee-SORE-us

Name means: “lizard from the Los Molles Formation”1

Ate: MeatIchthyosaursMiddle JurassicNot technically a dinosaur

Mollesaurus was a large, fast-swimming marine reptile that lived in the Jurassic seas. It looked a bit like a dolphin but was actually an ichthyosaur, not a dinosaur. With its big eyes and sharp teeth, it was a top hunter in the ocean.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

171 to 169 million years ago3

Middle Jurassic

Fossils found in

Neuquén Basin, northwestern Patagonia, Argentina1 2

Food

Meat3

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

cool stuff

Fun facts

Mollesaurus is one of the oldest known ophthalmosaurid ichthyosaurs, living about 171 to 170 million years ago.1

Its name comes from the Los Molles Formation in Argentina, where its fossils were found.1

The only known fossil of Mollesaurus is a partial skeleton including part of the skull and most of the backbone.1

Mollesaurus was a thunnosaur, meaning it had a tuna-like body built for fast swimming.1

Some scientists once thought Mollesaurus was a species of Ophthalmosaurus, but newer studies show it is its own genus.1

Mollesaurus and another ichthyosaur called Chacaicosaurus were found at the same spot in Argentina.1

AI-made picture of Mollesaurus — An AI-made picture of how Mollesaurus 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: Mollesaurus
Named by: Fernandez 19993
Group: Ichthyosaurs
Family / clade: Ophthalmosauridae3
Classification: Ichthyosauria > Ichthyosauromorpha3
Age of the rocks: 171 to 169 million years (Bajocian)3
Rock formations: Los Molles3
Countries: Argentina3
Fossil records: 2 in the Paleobiology Database3
Discovery: Mollesaurus was named by paleontologist Marta S. Fernández in 1999 based on a partial skeleton found in the Los Molles Formation of Argentina.1 3
Still debated: Scientists are not sure exactly how big Mollesaurus grew, because only one partial skeleton has been found.1

Where the facts come from

Mollesaurus (en.wikipedia.org)
A new ichthyosaur from the Los Molles Formation (early Bajocian), Neuquen Basin, Argentina | Journal of Paleontology | GeoScienceWorld (pubs.geoscienceworld.org)
Mollesaurus 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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