During more than twenty five years of intensive exploration and research on dinosaurs, the Department of Mineral Resources has discovers over 2,000 bones belonging to several groups of dinosaurs. On the basis of this material, five new dinosaur specimens have so far been described. They are Phuwianggosaurus sirindhornae, Siamosaurus suteethorni, Siamotyrannus isanensis, Isanosauruus attavipachi, and Psittacosaurus sattayaraki.