Fossil dinosaur samples haven't been found in Vietnam yet

 The university that I used to learnt at - Hanoi university of mining and geology is one of few places retaining fossil dinosaur samples in Vietnam. 

The samples, however, were discovered in Savannakhet, Laos by Prof. Josué Heilman Hoffet in 1936 and when he came to Vietnam to work as a teacher of geology at Indochina University established by the French in 1941, he brought some samples with him. 

The fossil samples belongs to the species named Tangvayosaurus, which is named after the site where they found the fossils.

Despite of the geographical proximity and contrary to the fact that people have been discovered a large quantity of fossil dinosaur samples in Laos, they haven't been found in Vietnam yet.

Dinosaurs mainly existed in Mesozoic era (252-66 Mega annum ago and their thriving time was Jura period (201-145 ma ago). 

Now take a look at the formation history of  Vietnam territory. There are few area were formed after Jura period (Hong river delta, central coastal plain, western central highland and most of the southern areas). The rest of the mainland Vietnam is form earlier. That's why there is a possibility that Vietnam was once the habitats of dinosaur. Tangvayosaurus, as mentioned above, existed in late cretaceous period (83-66 ma ago)

Vietnam and Laos are separated by Truong Son range. In Vietnam side, the terrain is mainly mountainous and often divided by tectonic fault rather than the terrain of wide and plain plateau like Laos. Therefore it is really difficult for any discovery.

Quangngai, November, 25th, 2022