Ratchasimasaurus Facts
Pronunciation: rat-cha-SEE-ma-SORE-us
Name meaning: Ratchasima lizard (after Nakhon Ratchasima province)
| Diet | Herbivore |
| Height | 2.5m |
| Length | 6m |
| Weight | 1.5 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Early Cretaceous |
| Type | Ornithopod |
| Location | Thailand |
Ratchasimasaurus was an ornithopod dinosaur that lived during the Early Cretaceous period, approximately 121 million years ago, in what is now northeastern Thailand. This herbivorous dinosaur belonged to a group called Styracosterna, which includes the famous Iguanodon and its relatives. However, the validity of Ratchasimasaurus as a distinct genus remains contentious amongst palaeontologists.
The dinosaur was discovered in the Khok Kruat Formation of Nakhon Ratchasima province and was estimated to have been around 6 metres long and 2.5 metres tall at the hip, weighing roughly 1.5 tonnes. Like other ornithopods, Ratchasimasaurus was primarily bipedal but could also move on all fours when feeding or resting. Its powerful hind limbs and long tail would have provided balance whilst walking upright.
As a herbivore, Ratchasimasaurus possessed the typical ornithopod features for plant processing, including rows of grinding teeth and powerful jaw muscles. It would have fed on ferns, cycads, and early flowering plants that grew in the warm, humid climate of Cretaceous Thailand. The dinosaur's hands were well-adapted for grasping vegetation, with thumb spikes that may have been used for defence or manipulation of food.
The species name R. suranareae honours Thao Suranari, a beloved 19th-century Thai war heroine, making this one of the few dinosaurs named after a historical figure from Southeast Asia.
What made Ratchasimasaurus distinctive?
Ratchasimasaurus shared many features common to styracosternan ornithopods, including a robust build, powerful hind limbs for bipedal locomotion, and hands equipped with defensive thumb spikes. Unfortunately, the fragmentary nature of the fossils makes it difficult to identify unique characteristics that would distinguish it from closely related species.
Behaviour
Like other ornithopods, Ratchasimasaurus likely lived in herds for protection against predators and may have migrated seasonally in search of fresh vegetation. It probably spent much of its time feeding on low-growing plants whilst on all fours, but could rear up on its hind legs to reach higher foliage or to scan for danger.
Discovery
Ratchasimasaurus was first described by Buffetaut and Suteethorn in 2011. The original fossils were discovered at Khok Kruat Formation, Nakhon Ratchasima province, Thailand.
Ratchasimasaurus FAQ
What did Ratchasimasaurus eat?
Ratchasimasaurus was a herbivore that fed on plants such as ferns, cycads, and early flowering plants. It used its rows of grinding teeth to process tough vegetation, and could feed both on all fours for low plants and rear up on its hind legs to reach higher foliage.
How big was Ratchasimasaurus?
Ratchasimasaurus was estimated to be around 6 metres long and 2.5 metres tall at the hip, weighing approximately 1.5 tonnes. However, these estimates are based on limited fossil material, so the actual size may have varied.
When did Ratchasimasaurus live?
Ratchasimasaurus lived during the
Early Cretaceous period, approximately 121.4 million years ago. This was a time when flowering plants were beginning to diversify and dinosaurs dominated terrestrial ecosystems.
Where was Ratchasimasaurus found?
Fossils of Ratchasimasaurus were discovered in the Khok Kruat Formation in Nakhon Ratchasima province, northeastern Thailand. This region has yielded numerous important dinosaur discoveries from the Cretaceous period.
How do you pronounce Ratchasimasaurus?
Ratchasimasaurus is pronounced 'rat-cha-SEE-ma-SORE-us'. The name can be broken down as Ratchasima (rat-cha-SEE-ma) plus saurus (SORE-us), meaning lizard.
What does Ratchasimasaurus mean?
Ratchasimasaurus means 'Ratchasima lizard', named after Nakhon Ratchasima province in Thailand where it was discovered. The species name suranareae honours Thao Suranari, a 19th-century Thai war heroine.
How fast could Ratchasimasaurus run?
The running speed of Ratchasimasaurus is unknown due to limited fossil evidence. However, like other ornithopods of similar size, it may have been capable of reaching moderate speeds when fleeing from predators, possibly around 15-25 km/h.
What type of dinosaur was Ratchasimasaurus?
Ratchasimasaurus was an ornithopod dinosaur, specifically belonging to a group called Styracosterna. However, some scientists consider it a nomen dubium, meaning the fossil evidence may be too fragmentary to definitively establish it as a separate genus.
Was Ratchasimasaurus related to birds?
As an ornithopod, Ratchasimasaurus was not closely related to birds. Birds evolved from theropod dinosaurs, whilst Ratchasimasaurus belonged to the ornithischian lineage, which includes dinosaurs like
Triceratops and
Stegosaurus.
How many Ratchasimasaurus fossils have been found?
Only limited fossil material of Ratchasimasaurus has been discovered, which is why some scientists question its validity as a distinct genus. The fragmentary nature of the remains makes it difficult to fully understand this dinosaur's anatomy and relationships.
