Three 'Species' of Plant-Eating Dinosaur are Really Just One

There may be a few fewer species than we once thought in the realm of the dinosaurs. Scientists have discovered that fossils that were once thought to be three, distinct dinosaurs actually belong to a single species.

So how did scientists mistake one dinosaur for three? No fossil in the same and sometimes, species vary only by a small amount physically. This means that it can relatively easy to think that there may possibly be enough differences to name a completely new species.

"Because of the vagaries of fossilization, no two fossils are the same," said Peter Dodson, the senior author of the new study, in a news release. "Animals are alive and they die, but what's crucial in paleontology is what happens to the animals after they die."

The dinosaur actually belongs to the genus Psittacosaurus. These creatures were named for the dinosaur's beaked face, not unlike a turtle's. So far about 15 species have been classified as Psittacosaurus. Yet with recent analysis, only nine of these are definite members. Known as being plant-eaters, these dinosaurs lived between 120 and 125 million years ago.

In order to better examine the fossils, the researchers used three-dimensional geometric morphometrics, which uses lasers to generate data about the shape of different specimens. More specifically, the researchers looked at Psittacosaurus skulls that were found in the fossilized ashes of the Lujiatun beds of China's Yixian Formation. In addition, the scientists also conducted a traditional study to examine the specimens. This allowed them to use both old and new techniques in order to compare the various "species."

"Our study found all these false 'species' that are not biological species but are apparent species caused by the process of fossilization," said Dodson.

The first time three-dimensional geometrics morphometrics has been used to study dinosaur fossils, it could lead to a re-examination of the taxonomic classifications of other dinosaur species, which could allow scientists to learn more about the fossils that they've discovered.

The findings are published in the journal PLOS One.