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Amanasaurus

Say it: ah-MAH-nah-SORE-us

Name means: “rain lizard”1

Ate: PlantsBeaked plant-eatersLate Triassic

Amanasaurus was a plant-eating dinosaur that lived about 233 million years ago in what is now Brazil. It had a beak-like mouth and walked on four legs, munching on ferns and other plants. This dinosaur was about the size of a large dog, making it one of the bigger plant-eaters of its time.2 6

Lived

237 to 227 million years ago6

Late Triassic

Fossils found in

Pivetta site, between Restinga Sêca and São João do Polêsine, Rio Grande do Sul, Brazil2 6

Food

Plants6 2

Length

up to 1.27 m3

estimate, largest known specimen

Weight

up to 3.5 kg3

estimate, 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 29 bananas

as long as 2.5 house cats nose to tailas long as 7 bananas end to endabout as heavy as a house catas heavy as 29 bananas

How big was Amanasaurus compared to YOU?

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

cool stuff

Fun facts

Amanasaurus lived during a time called the Carnian pluvial episode, a wet period when it rained a lot. Its name 'rain lizard' comes from that.1 2

Scientists know Amanasaurus from just two leg bones: a top part of a right thigh bone and a bottom part of a left thigh bone. These bones were found in the same spot.2 1

Amanasaurus was about the same size as the earliest dinosaurs that lived alongside it. This surprised scientists, who thought silesaurids were always smaller.2

The thigh bone of Amanasaurus had a special groove called a cleft between the top of the anterior trochanter and the shaft. This is the oldest such feature seen in any silesaurid.2

Amanasaurus is named after Dr. Sterling J. Nesbitt, a paleontologist who studied many Triassic reptiles. The species name 'nesbitti' honors his work.1 2

Some scientists think Amanasaurus might be a very early type of ornithischian dinosaur, the group that includes plant-eaters like Stegosaurus and Triceratops. Others say it is a close cousin of dinosaurs.2 1

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

?How big was Amanasaurus?

About 1.3 metres (4.3 feet) long, based on the larger leg bone found. That is roughly the size of a large dog.4

?Was Amanasaurus a dinosaur?

Scientists disagree. Some say it was a very early ornithischian dinosaur, while others say it was a close cousin of dinosaurs. Either way, it is a dinosauriform, meaning it is closely related to dinosaurs.5 1

?What did Amanasaurus eat?

It was a plant-eater. It used its beak-like mouth to munch on ferns and other plants that grew during the rainy Carnian period.4

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For dino experts

Scientific name: Amanasaurus
Named by: Müller and Garcia 20236
Group: Beaked plant-eaters
Family / clade: Silesauridae6
Classification: Ornithischia6
Age of the rocks: 237 to 227 million years (Carnian)6
Countries: Brazil6
Fossil records: 1 in the Paleobiology Database6
Discovery: Amanasaurus was named in 2023 by paleontologists Rodrigo T. Müller and Maurício S. Garcia. They studied two fossil leg bones found at the Pivetta site in Brazil.6 2
Still debated: Scientists are not sure if Amanasaurus was a true dinosaur or a very close relative. Some studies place it inside Ornithischia, while others put it just outside Dinosauria.2 1

Where the facts come from

Amanasaurus (en.wikipedia.org)
A new silesaurid from Carnian beds of Brazil fills a gap in the radiation of avian line archosaurs (nature.com)
Amanasaurus nesbitti | Dinosaur Database by DinoAnimals.com (dinoanimals.com)
Paleontólogos da UFSM descobrem nova espécie pré-histórica que preenche lacuna na evolução dos dinossauros – UFSM (ufsm.br)
A new silesaurid from Carnian beds of Brazil fills a gap in the radiation of avian line archosaurs | Scientific Reports (nature.com)
Amanasaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

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