New Tyrannosaur Fossils Rewrite the Story of T-Rex Origins

Post by : Bianca Suleiman

Photo: Reuters

For 50 years, a set of dinosaur bones sat quietly in a drawer at a museum in Mongolia. Scientists had thought they belonged to an already known dinosaur called Alectrosaurus. But recently, researchers discovered that they had made a mistake.

These bones are actually from a brand-new species of tyrannosaur, which is a group of dinosaurs that includes the famous Tyrannosaurus Rex (T-Rex). This new species has been named Khankhuuluu mongoliensis, which means "dragon prince of Mongolia." Scientists gave it this name because it’s smaller than the T-Rex, which is often called the "king" of dinosaurs.

This new dinosaur was about 13 feet long and weighed around 750 kilograms — about as big as a large horse. It lived about 90 million years ago and is believed to be an early ancestor of the T-Rex.

The bones were first dug up in the 1970s in southeastern Mongolia, but they were wrongly identified and then stored away in drawers at the Institute of Paleontology in Ulaanbaatar, the capital city. It wasn’t until a Canadian PhD student named Jared Voris visited the museum that the truth came out. He noticed the bones looked different and might belong to a separate species.

Darla Zelenitsky, a scientist from the University of Calgary, explained that the discovery helped clear up some confusion about the history of the tyrannosaur family. She said the family tree of these dinosaurs used to be quite “messy.”

Scientists now believe that Khankhuuluu — or a dinosaur similar to it — may have crossed from Asia to North America using a land bridge that once connected Siberia and Alaska. This happened around 20 million years before the T-Rex appeared.

Once in North America, tyrannosaurs changed and evolved into different kinds. Later, some of them went back to Asia and formed two new groups. One group had long, thin snouts and was smaller — like the "Pinocchio rex." The other group was much larger and included dinosaurs like the Tarbosaurus, which was almost the same size as the T-Rex.

Eventually, one of these giant dinosaurs returned to North America and became the famous T-Rex. It ruled as the top predator there for about two million years before a huge asteroid hit Earth 66 million years ago. That asteroid caused the extinction of most life, including all the dinosaurs that didn’t turn into birds.

This exciting discovery shows that there may be many more unknown species hiding in museum drawers around the world, just waiting to be recognized.