Siamosaurus in a hypothetical reconstruction Alive

  • Thailand
  • Siamosaurus suteethorni

Siamosaurus ( " reptile from Siam" ) is a genus of spinosauriden dinosaurs, which was first described by Buffetaut and Ingavat 1986 on the basis of teeth with the only kind Siamosaurus suteethorni (after Varavudh Suteethorn, a Thai paleontologists ). The teeth are from the Upper Jurassic Sao Khua formation at Phu Wiang in the Thai province of Khon Kaen.


From Siamosaurus suteethorni only teeth were found, similar in shape to those of Spinosaurus, making the assignment to the Spinosauridae was. In the following years, more teeth were found in layers of the Lower Cretaceous in Thailand, but also in Japan.

2004 parts of a theropod skeleton were found in the same formation, consisting of several parts of the spine, ribs, and a part of the midfoot.

Siamosaurus is so far the only species of this taxon from Asia, other findings are from Europe, Africa and South America.

Scientific Importance

Due to the sparse fossil material Siamosaurus suteethorni is considered by some scientists as a noun dubium and questioned the scientific validity of the description. According Siamosaurus was not included in systematic considerations of Spinosauridae in the past.