Lariosaurus

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

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

Ate: FishOther sea 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 ago3

Early Triassic to Middle Triassic

Fossils found in

Italy, Switzerland, Germany, Spain, France, the Netherlands, Austria, and China3 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)

Artist's life restoration of Lariosaurus — How Lariosaurus may have looked, by SimoneZoc. CC BY-SA 4.0, 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

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

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 18473
Group: Other sea reptiles
Family / clade: Nothosauridae3
Classification: Sauropterygia3
Age of the rocks: 251 to 237 million years ()3
Rock formations: Falang, Meride, Perledo-Varenna3
Countries: Italy, China, Germany, Spain, Switzerland, Netherlands3
Fossil records: 27 in the Paleobiology Database3
Also known as: Deirosaurus, Eupodosaurus, Macromerosauro, Macromerosaurus, Macromirosaurus, Rhaeticonia, Silvestrosaurus (older names now counted as the same animal)3
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)
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.