New analysis of dinosaur fossils reveal that a number of specimens of the genus Psittacosaurus are of a single species

Updated on: Monday, August 12, 2013

A new analysis of dinosaur fossils has revealed that a number of specimens of the genus Psittacosaurus once believed to represent three different species are all members of a single species.

The differences among the fossil remains that led other scientists to label them as separate species in fact arose from how the animals were buried and compressed, the study by University of Pennsylvania researchers has found.

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

The research involved a cutting-edge technique, known as three dimensional geometric morphometrics, which uses lasers to generate data about the shape of different specimens.

This is the first time the approach has been used to study dinosaur fossils and could lead to a re-examination of the taxonomic classifications of additional dinosaur species as well as other long-extinct fossil organisms.

The investigation focused on dinosaurs in the genus Psittacosaurus, a word that comes from the Greek for "parrot lizard."

The group was named for the animal's beaked face, not unlike that of a turtle. Originally discovered in 1923, 15 species have been classified as Psittacosaurus, though a recent analysis confirmed only nine of these as definite members of the genus.

These animals were small plant-eaters that lived 120 to 125 million years ago.

"Meat-eaters are sexy; plant-eaters are not. This isn't a flashy dinosaur. But it has an interesting feature in that it's one of the most abundant dinosaurs known to science," Dodson said.

Indeed, many hundreds of Psittacosaurus specimens have been found. This abundance made the genus ideal for comparative study, as it is easier to determine relationships within and between species when there are more individuals to compare.

The scientists examined Psittacosaurus skulls discovered in the fossilised ashes of the Lujiatun beds of northeastern China's Yixian Formation.

The study appears in the journal PLOS ONE.

New analysis of dinosaur fossils reveal that a number of specimens of the genus Psittacosaurus are of a single species

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