Dino card No. 0770 of 2,027

Haasiasaurus

Say it: HAH-see-uh-SORE-us

Name means: “Haas's lizard”1

Ate: MeatMosasaursLate CretaceousNot technically a dinosaur

Haasiasaurus was an early marine lizard, not a dinosaur, that lived about 100 to 93 million years ago. It was only about 1 meter (3.3 feet) long, making it one of the smallest and oldest mosasaurs. It swam in shallow seas near what is now the West Bank.1 3

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

Lived

100 to 94 million years ago3

Late Cretaceous

Fossils found in

Ein Yabrud, Palestinian West Bank1 3

Food

Meat3

Length

1 m1

estimate

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

as long as 2 house cats nose to tailas long as 6 bananas end to end

How big was Haasiasaurus compared to YOU?

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cool stuff

Fun facts

Haasiasaurus was one of the oldest known mosasaurs, living during the Cenomanian age of the Late Cretaceous.1 2

Its name was originally Haasia, but that name was already used for a millipede, so scientists changed it to Haasiasaurus in 2003.1 3

Fossils of Haasiasaurus were found at Ein Yabrud, a site that also produced ancient snakes with small legs, like Pachyrhachis.2

It lived in warm, shallow seas with surface temperatures similar to today's tropical oceans, around 20 to 30 degrees Celsius.2

Haasiasaurus is named after paleontologist Georg Haas, who studied fossils from Israel.1

Some scientists think Haasiasaurus might be a chimera, meaning its skull and body bones may come from different animals.1

This small mosasaur is closely related to other early marine lizards like Dallasaurus and Russellosaurus.2

AI-made picture of Haasiasaurus — An AI-made picture of how Haasiasaurus 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.

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For dino experts

Scientific name: Haasiasaurus
Named by: Polcyn et al. 20033
Group: Mosasaurs
Family / clade: Mosasauridae3
Classification: Mosasauroidea3
Age of the rocks: 100 to 94 million years (Cenomanian)3
Rock formations: Bet Meir or Amminadav3
Countries: Palestine3
Fossil records: 1 in the Paleobiology Database3
Discovery: Haasiasaurus was first described in 1999 under the name Haasia by Polcyn, Tchernov, and Jacobs. The name was changed to Haasiasaurus in 2003 because Haasia was already taken by a millipede.1 3
Still debated: Scientists are not sure if Haasiasaurus is truly a mosasaur or a more primitive pythonomorph lizard, because its skull and skeleton were not found together.1 2

Where the facts come from

Haasiasaurus (en.wikipedia.org)
Haasiasaurus gen. nov., a new generic name for the basal mosasauroid Haasia Polcyn et al., 1999 (researchgate.net)
Haasiasaurus 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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