Acta Geologica Sinica - English Edition
Volume 85, Issue 5, pages 969–976, October 2011
A New Iguanodontian Dinosaur from the Lower Cretaceous Khok Kruat Formation, Nakhon Ratchasima in Northeastern Thailand
Masateru SHIBATA, Pratueng JINTASAKUL & Yoichi AZUMA
Here we report a new iguanodontian dentary found from the Lower Cretaceous Khok Kruat Formation, Nakhon Ratchasima, northeast Thailand. A unique character, which is an elongated and flat shape of the dentary ramus, makes it possible to assign the specimen to the new genus of non-hadrosaurid iguanodontian, Ratchasimasaurus suranareae gen. et sp. nov. R. suranareae shows both primitive and derived characters, such as a caudally inclined coronoid process and alveolar trough with a primitive crown impression, and a derived buccal shelf between tooth row and coronoid process. The discovery of a new iguanodontian from the Indochina Terrene, considering that the previously reported “Probactrosaurus-like” iguanodontian, points out a great diversity of this group in the late Early Cretaceous in Thailand, and corresponds to the Asian iguanodontian diversity at that time.