Dino card No. 1317 of 2,027

Oplosaurus

Say it: OP-loh-SORE-us

Name means: “armed lizard or weapon lizard”1

Ate: PlantsLong-necksEarly Cretaceous

Oplosaurus was a huge, long-necked plant-eater that lived on the Isle of Wight during the Early Cretaceous. It is known from just one big tooth, but that tooth tells us it was a giant, like a Brachiosaurus. Imagine a gentle giant munching on leaves with a tooth as big as your hand!1 2

Lived

137 to 121 million years ago3

Early Cretaceous

Fossils found in

Brighstone Bay (formerly Brixton Bay), Isle of Wight, England1 3 2

Food

Plants2

Length

22 to 25 m1 2

estimate based on tooth size

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

as long as 6 cars parked in a rowas long as 140 bananas end to end

How big was Oplosaurus compared to YOU?

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

cool stuff

Fun facts

Oplosaurus is known only from a single tooth, found in the 1850s. This tooth is 85 mm (3.35 inches) tall, about as long as a credit card.1 2

The tooth looks very similar to a Brachiosaurus tooth, so scientists think Oplosaurus was a giant sauropod, maybe 25 metres (82 feet) long.1 2

Its name means 'armed lizard' or 'weapon lizard', probably because the tooth looked like a weapon. The species name armatus also means 'armed' in Latin.1

Some scientists think Oplosaurus might have been a turiasaur, a group of primitive sauropods with heart-shaped teeth. Others place it in the Camarasauridae family.1

The tooth has a pointed tip and wear facets from grinding plants. This shows Oplosaurus was a plant-eater that chewed its food.1

Oplosaurus lived on the Isle of Wight when it was a low plain with rivers and lakes. The climate was warm and humid, like a subtropical forest.1

Because only one tooth has been found, Oplosaurus is a 'tooth taxon'. Scientists are not sure if it is a valid genus or if the tooth belongs to another dinosaur like Pelorosaurus.1 2

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

?How big was Oplosaurus?

About 25 metres (82 feet) long, based on its tooth being as big as a Brachiosaurus tooth.1 2

?What did Oplosaurus eat?

It was a plant-eater. Its tooth has wear facets from grinding tough vegetation.1 2

?Where was Oplosaurus found?

On the Isle of Wight, England, in the Wessex Formation near Brighstone Bay.1 2

?Is Oplosaurus a dinosaur?

Yes, it is a sauropod dinosaur, a long-necked plant-eater from the Early Cretaceous.1 3

Ask Rex about Oplosaurus

Rex only answers questions about this page. 3 questions a day.

Rex is an AI and can make mistakes. He runs on servers in the EU and questions are never saved. Never type your name or other personal things.

Myth buster

Myth: Oplosaurus was an armoured dinosaur like Hylaeosaurus.

Truth: Scientists once thought the tooth belonged to an armoured dinosaur because it was sharp, but Oplosaurus is now considered a long-necked sauropod, not an armoured dinosaur.1

For dino experts

Scientific name: Oplosaurus
Named by: Gervais 18523
Group: Long-necks
Family / clade: Sauropoda3
Classification: Sauropodomorpha > Sauropoda3
Age of the rocks: 137 to 121 million years (Valanginian / Barremian)3
Countries: United Kingdom3
Fossil records: 1 in the Paleobiology Database3
Discovery: In 1852, geologist Thomas Wright reported a large tooth found near Brixton Bay on the Isle of Wight. French paleontologist Paul Gervais named it Oplosaurus armatus the same year.1
Still debated: Scientists are not sure if Oplosaurus is a valid dinosaur or if its tooth belongs to another sauropod such as Pelorosaurus or a turiasaur.1 2

Where the facts come from

Oplosaurus (en.wikipedia.org)
Oplosaurus, a possible Camarasaur from the Isle of Wight - DinoWight (dinowight.org.uk)
Oplosaurus 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.

Rex is hungry! Dino Wiki is a dad's project for his dino-loving son, free with no ads. Grown-ups can feed Rex a snack to help keep it online.Feed Rex