Dino card No. 1422 of 2,027

Phosphorosaurus

Say it: FOS-for-oh-SORE-us

Name means: “phosphate lizard”1

Ate: MeatMosasaursLate CretaceousNot technically a dinosaur

Phosphorosaurus was a small marine lizard that lived in the late Cretaceous seas. It had huge eyes that helped it see in the dark, so it could hunt at night or in deep water. It was an ambush predator, waiting quietly for prey like squid and glowing fish.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

72 to 66 million years ago3

Late Cretaceous

Fossils found in

Belgium (Craie de Ciply Formation) and Japan (Hakobuchi Formation, Hokkaido)1 3

Food

Meat1

Length

2.5 to 3.5 m1

estimated from skull length of about 50 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 4 dogs nose to tailas long as 19 bananas end to end

How big was Phosphorosaurus compared to YOU?

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

cool stuff

Fun facts

Phosphorosaurus had eyes that pointed forward, giving it binocular vision and depth perception, which is rare among mosasaurs.1

It was a small mosasaur, only about 2.5 to 3.5 metres long, much smaller than giants like Mosasaurus.1

The name Phosphorosaurus means 'phosphate lizard' because its fossils were found in phosphate-rich rocks in Belgium.1

Two species are known: Phosphorosaurus ortliebi from Belgium and Phosphorosaurus ponpetelegans from Japan.1

The Japanese species P. ponpetelegans was discovered in a clean creek called Pankerusano-sawa, and its name means 'elegant creek lizard'.1

Phosphorosaurus lived during the Maastrichtian age, about 72 to 66 million years ago, just before the dinosaurs went extinct.1 3

It was an ambush predator, not a fast swimmer, so it likely hid and waited for prey to come close.1

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

?How big was Phosphorosaurus?

About 3 metres (10 feet) long. That is small for a mosasaur, about the size of a small car.2

?Did Phosphorosaurus have binocular vision?

Yes. Its eyes pointed forward, giving it depth perception. This is rare among mosasaurs and helped it hunt in the dark.2

?What did Phosphorosaurus eat?

It likely ate squid and bioluminescent fish, like modern lanternfish. It was an ambush predator that waited for prey.1 2

?Where was Phosphorosaurus found?

Fossils have been found in Belgium and Japan. One species, P. ponpetelegans, was discovered in a creek in Hokkaido, Japan.1 2

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For dino experts

Scientific name: Phosphorosaurus
Named by: Dollo 18893
Group: Mosasaurs
Family / clade: Mosasauridae3
Classification: Mosasauroidea3
Age of the rocks: 72 to 66 million years (Maastrichtian)3
Rock formations: Mocuio, Craie de Ciply, Hakobuchi3
Countries: Angola, Belgium, Japan3
Fossil records: 3 in the Paleobiology Database3
Discovery: Belgian paleontologist Louis Dollo named Phosphorosaurus in 1889, based on a partial skull from the Craie de Ciply Formation in Belgium. The second species, P. ponpetelegans, was described in 2015 from a well-preserved skeleton found in Hokkaido, Japan.1
Still debated: Scientists are not sure if Phosphorosaurus ponpetelegans really belongs to this genus or if it should be placed in a new genus, as some studies suggest it is more closely related to Halisaurus.1

Where the facts come from

Phosphorosaurus (en.wikipedia.org)
International research partnership yields discovery of a new fossil species, UC reveals new fossil discovery, University of Cincinnati (magazine.uc.edu)
Phosphorosaurus 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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