Dino card No. 0857 of 2,027

Ichthyotitan

Say it: IK-thee-oh-TIE-tan

Name means: “giant fish lizard of the Severn”1

Ate: MeatIchthyosaursLate TriassicNot technically a dinosaur

Ichthyotitan was one of the biggest marine reptiles that ever lived. It was a giant ichthyosaur, a fish-shaped reptile that swam in the seas during the time of the dinosaurs. Scientists think it could have been as long as a blue whale!2 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

206 to 201 million years ago7

Late Triassic

Fossils found in

Somerset, UK (Blue Anchor and Lilstock)2 1

Food

Meat3

Length

20 to 25 m2 1

estimated from a jaw bone over 2 m long

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 Ichthyotitan compared to YOU?

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

cool stuff

Fun facts

Ichthyotitan is known from only two jaw bones, called surangulars, found on the coast of Somerset, England.2 1

The larger jaw bone is over 2 metres long, which helped scientists estimate the whole animal was about 25 metres in length.2 1

Ichthyotitan lived at the very end of the Triassic Period, about 205 to 201 million years ago.3

It is the first giant ichthyosaur to be named from the Rhaetian stage of the Triassic.2 1

Ichthyotitan probably belongs to a group called shastasaurids, which includes some of the largest ichthyosaurs.2 1

The name Ichthyotitan means 'giant fish lizard', from Greek words for fish and giant, plus the Severn River estuary where the fossils were found.1

The jaw bones show unique features, like an upturned back end and a bulbous coronoid process, that set Ichthyotitan apart from other giant ichthyosaurs.1

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

?How big was Ichthyotitan?

Ichthyotitan was enormous, scientists estimate it reached about 25 metres long, which is about 5 metres shorter than a 30 metre blue whale. It is likely the largest marine reptile ever discovered.4 2

?Was Ichthyotitan a dinosaur?

No, Ichthyotitan was not a dinosaur. It was an ichthyosaur, a type of marine reptile that swam in the oceans at the same time as dinosaurs lived on land.5

?What did Ichthyotitan eat?

Scientists are not certain, but because Ichthyotitan was a shastasaurid ichthyosaur, it probably ate fish and squid. Its large size suggests it was a top predator in its ocean.6

?When did Ichthyotitan live?

Ichthyotitan lived at the very end of the Triassic Period, about 205 to 201 million years ago. It died out in the mass extinction that ended the Triassic.6 4

?Where was Ichthyotitan found?

Its fossils were found on the coast of Somerset, England, near the Severn Estuary. The first jaw bone was discovered by a father and his 11-year-old daughter in 2020.4 5

?How do scientists know how big Ichthyotitan was?

They compared its jaw bone (the surangular) to the same bone in other giant ichthyosaurs. The jaw is over 2 metres long, and scaling it up gives a body length of about 25 metres.2 6

?Could Ichthyotitan swim?

Yes, Ichthyotitan was a marine reptile that lived in the ocean and swam using its flippers and tail. It was built like a fish and was a fast, powerful swimmer.6

?Is Ichthyotitan bigger than a blue whale?

No, Ichthyotitan was about 25 metres long, while the biggest blue whales can reach about 30 metres. So Ichthyotitan was almost as big, but not quite as large as the largest blue whales.5

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Myth buster

Myth: Some people think Ichthyotitan was a dinosaur.

Truth: Ichthyotitan was an ichthyosaur, a marine reptile that lived in the sea, not a dinosaur. Dinosaurs lived on land.2

For dino experts

Scientific name: Ichthyotitan
Named by: Lomax et al. 20247
Group: Ichthyosaurs
Family / clade: Shastasauridae7
Classification: Ichthyosauria > Ichthyosauromorpha7
Age of the rocks: 206 to 201 million years (Rhaetian)7
Rock formations: Westbury7
Countries: United Kingdom7
Fossil records: 1 in the Paleobiology Database7
Discovery: Ichthyotitan was named in 2024 by Lomax and colleagues based on a jaw bone found at Blue Anchor, Somerset, UK. A second jaw bone from Lilstock, found earlier in 2018, was also assigned to this species.2 1
Still debated: Scientists are not sure whether Ichthyotitan belongs to the shastasaurid family because the known fossils are too incomplete.2 1

Where the facts come from

The last giants: New evidence for giant Late Triassic (Rhaetian) ichthyosaurs from the UK (pmc.ncbi.nlm.nih.gov)
The last giants: New evidence for giant Late Triassic (Rhaetian) ichthyosaurs from the UK | PLOS One (journals.plos.org)
PBDB Taxon (paleobiodb.org)
Giant marine reptile found in the UK could be the largest ever discovered | Natural History Museum (nhm.ac.uk)
Gigantic marine reptile's fossils found by British girl and father (reuters.com)
Ichthyotitan (Wikipedia) (Wikipedia)
Ichthyotitan 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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