Dino card No. 1016 of 2,027

Lariosaurus

Say it: LAR-ee-oh-SORE-us

Name means: “lizard from Larius, the ancient name of Lake Como”1

Ate: FishSea reptilesEarly Triassic to Middle TriassicNot technically a dinosaur

Lariosaurus was a small, ancient sea reptile that lived in warm, shallow seas during the Triassic Period. It had a short neck, small flippers, and webbed feet, and it probably spent a lot of time hunting in shallow water or even on land.1 2

Fun fact: this sea reptile swam while dinosaurs walked on land. Everyone calls them dinos, but they were a different branch of reptiles.

Lived

251 to 237 million years ago4

Early Triassic to Middle Triassic

Fossils found in

Italy, Switzerland, Germany, Spain, France, the Netherlands, Austria, and China4 1

Food

Fish1

Length

0.7 to 0.8 m1

based on complete specimens of L. xingyiensis (70.5 cm) and L. hongguoensis (up to 80 cm)

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

as long as 1.5 house cats nose to tailas long as 4 bananas end to end

How big was Lariosaurus compared to YOU?

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

cool stuff

Fun facts

Lariosaurus was one of the smallest nothosaurs, measuring less than one meter long.1

Its front legs were adapted into paddles, but its back legs still had five toes, which is unusual among nothosaurs.1

Scientists think Lariosaurus could give birth to live young, because fossils of babies have been found inside adults.1

A fossil with preserved skin shows that Lariosaurus had webbed hands and feet, like a duck.2

Lariosaurus had a short neck and small flippers, making it a poor swimmer compared to other nothosaurs.1

The first Lariosaurus fossil was discovered in 1830 near Lake Como, Italy, making it one of the earliest known marine reptiles from the Alps.1

Lariosaurus had a sturdy armor of belly ribs (gastralia) that protected its underside.1

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

?What did Lariosaurus eat?

It ate small prey like fish and other reptiles. One fossil had two young placodonts (a type of shelled reptile) in its stomach.1

?How did Lariosaurus swim?

It swam by rowing its strong front limbs like a seal, using a 'flying-rowing' motion. Its hands and feet were webbed, not flippers.2 3

?Did Lariosaurus have live babies?

Yes, scientists think it gave birth to live young. Fossils of baby Lariosaurus have been found inside adults.1

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Myth buster

Myth: Some people thought Lariosaurus was a dinosaur or a stegosaur.

Truth: Lariosaurus is a nothosaur, a type of marine reptile, not a dinosaur. The nothosaur Eupodosaurus was once mistaken for a stegosaurian dinosaur but is now considered the same as Lariosaurus.1

For dino experts

Scientific name: Lariosaurus
Named by: Curioni 18474
Group: Sea reptiles
Family / clade: Nothosauridae4
Classification: Sauropterygia4
Age of the rocks: 251 to 237 million years ()4
Rock formations: Falang, Meride, Perledo-Varenna4
Countries: Italy, China, Germany, Spain, Switzerland, Netherlands4
Fossil records: 27 in the Paleobiology Database4
Also known as: Deirosaurus, Eupodosaurus, Macromerosauro, Macromerosaurus, Macromirosaurus, Rhaeticonia, Silvestrosaurus (older names now counted as the same animal)4
Discovery: Lariosaurus was named in 1847 by Curioni, based on a fossil found in 1830 at Perledo on Lake Como, Italy.1
Still debated: Scientists debate whether the genera Ceresiosaurus and Silvestrosaurus should be considered the same as Lariosaurus.1

Where the facts come from

Lariosaurus (en.wikipedia.org)
The first specimen with skin preserved of Lariosaurus (Eusauropterygia) from the Middle Triassic of Monte San Giorgio (Switzerland) allows inferences about its swimming method | Swiss Journal of Palaeontology | Springer Nature Link (link.springer.com)
An ancient reptile’s fossilized skin reveals how it swam like a seal (sciencenews.org)
Lariosaurus 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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