The fossils of a newly discovered long-necked dinosaurs are forcing scientists to rethink the origins of one the most iconic dinosaur lineages.

Artistic rendition of Lingwulong shenqi. Credit: Zhang Zongda.

Xing Xu and colleagues at the Chinese Academy of Sciences in Beijing examined the partial skeletons of as many ten individuals belonging to a new sauropod species. Sauropods were among the largest creatures to have ever walked Earth, a family of dinosaurs that includes Brontosaurus or Diplodocus.

The new species was named Lingwulong shenqi, which literally means “amazing dragon of Lingwu”, after the town near where it was found.

What’s special about this new dinosaur is that seems like it’s the oldest Diplodocoid found so far, pushing back the appearance of advanced sauropods by 15 million years. Diplodocoidea is a superfamily of sauropod dinosaurs, which included some of the longest animals of all time, including slender giants like Supersaurus, Diplodocus, Apatosaurus, and Amphicoelias.

Lingwulong wasn’t nearly as large as its most famous cousins, the largest individual identified by the Chinese researchers being about 18 meters (57 feet) long. Like most sauropods, the “amazing dragon” must have congregated in groups and stuck to a vegetarian diet. Because its neck wasn’t as long as other sauropods, scientists think that Lingwulong grazed on low- soft plants with its peg-like teeth.

Being the earliest member of its evolutionary family (Diplodocoidea), the dinosaur’s discovery in East Asia — which lived during a time when the region was still connected to other continents — will likely force palaeontologists to re-evaluate how sauropods appeared and evolved. Before this dinosaur was identified, the prevailing line of thought was that advanced sauropods first appeared in the late Jurassic and quickly spread throughout the planet. Now, it seems like these dinosaurs evolved earlier and spread slower than previously thought.

Neosauropod fossils have been found in North America, Europe, and eastern Africa, but until now, none were older than 160 million years old, nor was any found in Asia.

“The new discovery challenges conventional biogeographical ideas, and suggests that dispersal into East Asia occurred much earlier than expected,” the researchers wrote in the journal Nature Communications. “Moreover, the age of this new taxon indicates that many advanced sauropod lineages originated at least 15 million years earlier than previously realised, achieving a global distribution while Pangaea was still a coherent landmass.”

There are still many unexplored areas in China, which Xu and colleagues hope to investigate them in order to unravel the sauropod family tree even further.