From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Temporal range: Early Cretaceous, Aptian
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Suborder: Ornithopoda
Clade: Iguanodontia
Genus: Ratchasimasaurus
Shibata, Jintasakul, & Azuma, 2011
Type species
Ratchasimasaurus suranareae
Shibata, Jintasakul, & Azuma, 2011

Ratchasimasaurus (meaning "Ratchasima lizard") is a genus of non-hadrosaurid iguanodontian ornithopod dinosaur from Early Cretaceous (Aptian stage) Khok Kruat Formation of Nakhon Ratchasima Province in northeastern Thailand. The type and only species is R. suranareae, named after Thao Suranari, a 19th-century war heroine.[1] It was considered by one study to be a nomen dubium, diagnosed with characters widespread in Styracosterna.[2]


One autapomorphy (unique characteristic) of Ratchasimasaurus is its elongated and flat ramus of the dentary. Ratchasimasaurus shows both primitive and derived characters for Iguanodontia, such as "a caudally inclined coronoid process and alveolar trough with a primitive crown impression, and a derived buccal shelf between the tooth row and the coronoid process".[1]


  1. ^ a b Shibata M., Jintasakul P., Azuma Y. (2011). "A new iguanodontian dinosaur from the Lower Cretaceous Khok Kruat Formation, Nakhon Ratchasima in northeastern Thailand". Acta Geologica Sinica (English Edition). 85 (5): 969–976. doi:10.1111/j.1755-6724.2011.00530.x.CS1 maint: Multiple names: authors list (link)
  2. ^ "Phylogeny and Biogeography of Iguanodontian Dinosaurs, with Implications from Ontogeny and an Examination of the Function of the Fused Carpal-Digit I Complex - ProQuest".