The Thai dinosaur is a cousin of T. rex

Scientists from the University of Bonn and the Sirindhorn Museum in Thailand have identified two new species of dinosaurs. They analyzed fossil discoveries already discovered 30 years ago in Thailand. Both species are distant relatives of T. rex, but with a somewhat more primitive structure. They were effective predators. The results have now been published in the journal Acta Palaeontologica Polonica.

Three decades ago, a Thai museum employee discovered fossilized bones during excavations. He gave them to the Sirindhorn Museum, where they were never examined in detail. "Five years ago, I discovered these discoveries during my research," says Adun Samathi. The Thai paleontologist is currently preparing his Ph.D. at the Steinmann Institute of Geology, Mineralogy and Paleontology of the University of Bonn. He brought some fossil casts here to analyze with his supervisor, Professor Martin Sander, using state-of-the-art methods.

The results cast a new look at the history of megaraptors ("giant thieves"). Among the members of this group of carnivorous predatory dinosaurs are the tyrannosaurus rex. Like the T. rex, they ran on their hind legs. Unlike the tyrant lizard, however, their arms were strong and armed with long claws. They also had more delicate heads ending in a long snout. "We were able to assign the bones to a megaraptor novel, which we named Phuwiangvenator yaemniyomi," says Samathi. The name recalls on the one hand the location, the Phuwiang District, and on the other hand the discoverer of the first Thai dinosaur fossil, Sudham Yaemniyom.

Phuwiangvenator was probably a fast runner. With a length of about six meters, it was considerably smaller than the T. rex, which measured about twelve meters. Megaraptors have so far been discovered mainly in South America and Australia. "We compared Thai fossils to discoveries," Samathi said. "Various characteristics of Phuwiangvenator indicate that he is one of the first representatives of this group.We consider this as an indication that the megapaptors are from Southeast Asia and then extended to other regions. "

During his research in Thailand, the PhD student discovered other unidentified fossils. They also belong to a predatory dinosaur, which was a little smaller with a length of about 4.5 meters. The material was not sufficient to clarify the exact pedigree. However, scientists assume that a smaller dinosaur, named Vayuraptor nongbualamphuenisis, is also related to Phuwiangvenator and T. rex. "Maybe the situation can be compared to that of African big cats," says Samathi. "If Phuwiangvenator was a lion, Vayuraptor would be a cheetah."

The two new predatory dinosaurs will be presented to the public today on the occasion of the Sirindhorn Museum's tenth anniversary. With the support of his blue blood: the event will be opened by Thai princess Maha Chakri Sirindhorn.