Credit: Natural History Museum, London/Mark Witton

Researchers have discovered the fossils of what might be the earliest known dinosaur. But they didn't find them in the ground - they found them sitting on a shelf.

The fossils of the dinosaur, Nyasasaurus parringtoni, were part of a collection at the Natural History Museum in London. They were originally collected in the 1930s in Tanzania. An international team decided to take another look at the fossils recently.

"This work highlights the important role of museums in housing specimens whose scientific importance might be overlooked unless studied and restudied in detail," co-researcher Paul Barrett said in a press release. “Many of the more important discoveries in paleontology are made in the lab, or museum storerooms, as well as in the field.”

The researchers had one arm bone and six vertebrae to work with, but that's often a lot of information for paleontologists to work from. For example, by examining the bones, they could tell that they experienced rapid growth, something common for dinosaurs. The bones also contained a lot of cells and blood vessels, which are also indicators of rapid growth. Those features are also seen in birds - the descendants of dinosaurs.

"Although we only know Nyasasaurus from fossil fragments, the anatomy of its upper arm bone and hip vertebrae have features that are unique to dinosaurs, making us confident that we’re dealing with an animal very close to dinosaur origin," said lead researcher Dr. Sterling Nesbit in a press release.

From the fossils the researchers have, the Nyasasaurus was between 7 to 10 feet in length and weighed somewhere between between 45 and 135 pounds. The dinosaur evolved in the Mid-Triassic, between 245 and 235 million years ago.

"Nyasasaurus and its age have important implications regardless of whether this taxon is a dinosaur or the closest relatives of dinosaurs," Nesbitt said in a separate release. "It establishes that dinosaurs likely evolved earlier than previously expected and refutes the idea that dinosaur diversity burst onto the scene in the Late Triassic, a burst of diversification unseen in any other groups at that time."

Another benefit of this find is that it provides further evidence that dinosaurs evolved in the southern portion of Pangaea, the supercontinent that existed in the Triassic period. The portions where dinosaurs evolved would eventually drift into Africa, Antarctica, and South America.

As Barrett stated in the release, "The new findings place the early evolution of dinosaurs and dinosaur-like reptiles firmly in the southern continents."
