Psittacosaurus Dinosaur Skull Study Reveals Three Species Are Actually One

08/13/2013 02:22 pm ET | Updated Aug 14, 2013

Were scientists all wrong when it came to Psittacosaurus -- or "parrot lizard" -- dinosaurs? A new study has found that multiple skulls of a single species were mislabeled for years as three different species. Oops.

Researchers at the University of Pennsylvania uncovered this identity crisis using a high-tech technology that generates 3D renderings, similar to a CT scan, to measure and analyze differences in the shape of Psittacosaurus skulls from northeastern China. They found that variations in shape could be explained by the skulls being crushed and molded differently as they gradually turned into fossils over time -- and so the fossils didn't represent separate species after all.

"It takes a great deal of effort for sedimentary processes to bury a carcass," study co-author Dr. Peter Dodson, a professor of veterinary anatomy and paleontology at the university told The Huffington Post. "The chances of it being buried without any parts being lost are actually very poor. So paleontologists are almost always dealing with partial skeletons."

A small, horned dinosaur that may have stood at around 2 feet tall and 4 feet long, Psittacosaurus is thought to have lived around 100 million years ago. Fossils of the dinosaur have been found across Mongolia, China, Russia and perhaps Thailand, making it a good candidate for study because of its large sample size.

“This isn’t a flashy dinosaur," Dodson said in a written statement. "But it has an interesting feature in that it’s one of the most abundant dinosaurs known to science.”

This study was the first time the 3D geometric technology was used to examine dinosaur fossils. Dodson told HuffPost that the new research analysis method could be of use in other studies.

"It is a very valuable technique, and there is no question it will be used in the future on other types of dinosaurs," he said, adding that it would not be a surprise if other dinosaur species also turned out to be duplicates.

“Hopefully this will open up the paleontological community to using three-dimensional geometrics morphometrics in a variety of ways,” study co-author Brandon Hedrick, a doctoral student at the university, said in the written statement. “This technique has limitless applications to understanding dinosaurs.”

This new research published in the journal PLOS One on Aug. 9.

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