Dino card No. 1446 of 2,015

Pliosaurus

Say it: PLY-oh-SORE-us

Name means: “more lizard”1

Ate: MeatPlesiosaursMiddle Jurassic to Late CretaceousNot technically a dinosaur

Pliosaurus was a giant marine reptile that ruled the Jurassic oceans. It had a huge head, a short neck, and powerful jaws full of sharp teeth. This predator could grow as long as a school bus and ate big prey like other sea creatures.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 66 million years ago3

Middle Jurassic to Late Cretaceous

Fossils found in

United Kingdom (especially England), France, Russia, Norway, Argentina, and Poland3

Food

Meat1

Length

10 to 15 m2

estimates are debated

Artist's life restoration of Pliosaurus — How Pliosaurus may have looked, by Dmitry Bogdanov. CC BY-SA 3.0, via Wikimedia Commons. Scientists still argue about colours and details.

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

cool stuff

Fun facts

Pliosaurus had a skull that could be up to 2.1 metres (about 7 feet) long, making it one of the largest-headed marine reptiles.1

Its teeth were trihedral, meaning they had three flat sides, which helped it grip slippery prey.1

Pliosaurus lived during the Late Jurassic, about 165 to 66 million years ago, and its fossils are often found in the Kimmeridge Clay Formation in England.3

The first Pliosaurus fossil was discovered in 1822 near Weymouth, England, and it was named by the famous scientist Richard Owen in 1841.1

Pliosaurus was a plesiosaur, but unlike the long-necked plesiosaurs, it had a short neck and a huge head.1

Some scientists think Pliosaurus could grow up to 15 metres (about 49 feet) long, but these estimates are debated.2

Myth buster

Myth: Pliosaurus was a dinosaur.

Truth: Pliosaurus was not a dinosaur. It was a marine reptile called a plesiosaur, which lived in the ocean during the time of dinosaurs.1

For dino experts

Scientific name: Pliosaurus
Named by: (Owen 1841)3
Group: Plesiosaurs
Family / clade: Pliosauridae3
Classification: Plesiosauria > Pliosauridae > Sauropterygia3
Age of the rocks: 165 to 66 million years (Callovian to Maastrichtian)3
Rock formations: Kimmeridge Clay, Coral Rag, Oxford Clay3
Countries: United Kingdom, France, Russia, Norway, Argentina, Poland3
Fossil records: 57 in the Paleobiology Database3
Also known as: Ischyrodon, Spondylosaurus, Stretosaurus (older names now counted as the same animal)3
Discovery: The first Pliosaurus fossils were found in the early 1800s in England. Richard Owen named the genus Pliosaurus in 1841, based on a partial skeleton from Market Rasen, Lincolnshire.1
Still debated: Scientists still debate the exact maximum size of Pliosaurus, with estimates ranging from 10 to 15 metres long.2

Where the facts come from

A Giant Pliosaurid Skull from the Late Jurassic of England | PLOS One (journals.plos.org)
A taxonomic revision of the genus Pliosaurus (Owen, 1841a) Owen, 1841b (geologi.no)
Pliosaurus 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.