Ratchasimasaurus

Say it: rat-cha-SEE-mah-SORE-us

Name means: “Nakhon Ratchasima lizard”1

Ate: PlantsBeaked plant-eatersEarly Cretaceous

Ratchasimasaurus was a plant-eating dinosaur that lived in what is now Thailand. It had a long, flat jawbone that helped it chew tough plants. This dinosaur was about the size of a small car.1 2

Lived

121 to 113 million years ago3

Early Cretaceous

Fossils found in

Ban Pong Malaengwan, Nakhon Ratchasima province, northeastern Thailand3 1

Food

Plants3

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

cool stuff

Fun facts

Ratchasimasaurus is only known from a single left lower jawbone, called a dentary, which is 198.1 millimetres (7.80 inches) long.1

Its jawbone was long and flat, a unique feature that helps scientists tell it apart from other dinosaurs.1 2

This dinosaur lived during the Early Cretaceous period, about 121 to 113 million years ago.3

Ratchasimasaurus had both primitive and advanced features, like a backward-slanting coronoid process and a shelf between its teeth and jaw joint.1 2

The fossil was found by a local farmer near a pond in Thailand, likely between 2002 and 2004.1

Its species name, suranareae, honors Thao Suranari, a 19th-century war heroine from Thailand.1

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

?What did Ratchasimasaurus eat?

Ratchasimasaurus was a plant-eating dinosaur, as shown by its beaked mouth and jaw features for chewing tough plants. Its diet is listed as herbivore in the Paleobiology Database.3

?How big was Ratchasimasaurus?

The only known fossil is a jawbone, so its full size is uncertain. The dentary is 198.1 millimetres (7.80 inches) long, and the dinosaur was about the size of a small car, based on the page's intro.1

?When did Ratchasimasaurus live?

It lived during the Early Cretaceous period, about 121 to 113 million years ago (Aptian stage). This is based on the age range given in the Paleobiology Database.3

Ask Rex about Ratchasimasaurus

Rex only answers questions about this page. 3 questions a day.

Rex is an AI and can make mistakes. He runs on servers in the EU and questions are never saved. Never type your name or other personal things.

For dino experts

Scientific name: Ratchasimasaurus
Named by: Shibata et al. 20113
Group: Beaked plant-eaters
Family / clade: Hadrosauroidea3
Classification: Ornithischia > Ornithopoda > Iguanodontia3
Age of the rocks: 121 to 113 million years (Aptian)3
Rock formations: Khok Kruat3
Countries: Thailand3
Fossil records: 1 in the Paleobiology Database3
Discovery: Ratchasimasaurus was named in 2011 by Masateru Shibata, Pratueng Jintasakul, and Yoichi Azuma based on a jawbone found in the Khok Kruat Formation of Thailand.3 1
Still debated: Some scientists think Ratchasimasaurus might be a nomen dubium, meaning its fossils are too incomplete to be sure it is a distinct species.1

Where the facts come from

Ratchasimasaurus (en.wikipedia.org)
A New Iguanodontian Dinosaur from the Lower Cretaceous Khok Kruat Formation, Nakhon Ratchasima in Northeastern Thailand (onlinelibrary.wiley.com)
Ratchasimasaurus 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.

Rex is hungry! Dino Wiki is a dad's project for his dino-loving son, free with no ads. Grown-ups can feed Rex a snack to help keep it online.Feed Rex