Osmakasaurus

Say it: oz-MAK-ah-SORE-us

Name means: “canyon lizard”1

Ate: PlantsBeaked plant-eatersLate Jurassic to Early Cretaceous

Osmakasaurus was a plant-eating dinosaur that lived about 137 million years ago. It walked on two legs but could also go on all fours to eat low plants. Its fossils were found in a canyon in South Dakota, USA.1 5

Lived

155 to 121 million years ago5

Late Jurassic to Early Cretaceous

Fossils found in

Buffalo Gap, South Dakota, USA1

Food

Plants5

Length

4 to 5 m3

Weight

300 kg4

largest known specimen

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

How long was it?

How heavy was it?

as heavy as 10 big dogs

as long as 5 dogs nose to tailas long as 28 bananas end to endas heavy as 60 watermelons

How big was Osmakasaurus compared to YOU?

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cool stuff

Fun facts

Osmakasaurus was first thought to be a different dinosaur called Camptosaurus depressus.1

The name Osmakasaurus comes from the Lakota word 'ósmaka' meaning canyon.1

Its fossils were found in the Lakota Formation, which is Early Cretaceous in age, about 137 million years old.1

The only known specimen of Osmakasaurus is a partial skeleton discovered in 1896 by Nelson Horatio Darton.1

Osmakasaurus belongs to a group of plant-eating dinosaurs called iguanodontians, which are relatives of the famous Iguanodon.5 1

Scientists once thought Osmakasaurus belonged to the genus Planicoxa, but later studies gave it its own genus.1 2

AI-made picture of Osmakasaurus — An AI-made picture of how Osmakasaurus 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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Scientific name: Osmakasaurus
Named by: McDonald 20115
Group: Beaked plant-eaters
Family / clade: Iguanodontia5
Classification: Ornithischia > Ornithopoda > Iguanodontia5
Age of the rocks: 155 to 121 million years (Kimmeridgian / Barremian)5
Rock formations: Lakota, Morrison5
Countries: USA5
Fossil records: 3 in the Paleobiology Database5
Discovery: The first fossils of Osmakasaurus were found by Nelson Horatio Darton in 1896 in South Dakota. It was named Osmakasaurus by Andrew T. McDonald in 2011.1
Still debated: Scientists are not sure exactly how big Osmakasaurus was because only a partial skeleton has been found.1

Where the facts come from

Osmakasaurus (en.wikipedia.org)
The taxonomy of species assigned to Camptosaurus (Dinosauria: Ornithopoda) | Zootaxa (biotaxa.org)
PaleoCodex :: Osmakasaurus (paleocodex.com)
Osmakasaurus depressus | Dinosaur Database by DinoAnimals.com (dinoanimals.com)
Osmakasaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

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