Genus: Siamotyrannus BUFFETAUT, SUTEETHORN & TONG, 1996
Etymology: Generic name from Siam, the old name of Thailand, Greek, tyrannos, “tyrant”: Siam Tyrant.

Species: isanensis BUFFETAUT, SUTEETHORN & TONG, 1996
Etymology: Isan, the local name for the northeastern part of Thailand.

Holotype: PW9-1

Locality: Phu Wiang 9, Phu Wiang District, Khon Kaen Province, northeastern Thailand.

Horizon: Sao Khua Formation, Khorat Group.

Biostratigraphy:

Age: Aptian-Albian Stage, Middle Gallic Subepoch, Upper Early Cretaceous Epoch, Early Cretaceous.

Material: Left half of the pelvis, sacrum, 13 anterior most caudal vertebrae, 7 chevron bones, and 5 dorsal vertebrae.

 

Note: There is some question on whether or not this genus is a tyrannosaurid.