Professor helps identify new dinosaur species

Carthage professor Thomas Carr in the Dinosaur Discovery Museum in Kenosha.

Carthage biology professor Thomas Carr has co-authored a paper published this week about a new dinosaur species. Meet Alioramus altai — an eight-horned, slender-snouted cousin of Tyrannosaurus rex.

The paper will be published in the Proceedings of the National Academy of Sciences on Oct. 13. It was published online on Oct. 5.

"The article describes a brand new species of dinosaur that was completely unknown before," said Prof. Carr, a vertebrate paleontologist and senior scientific advisor for the Dinosaur Discovery Museum in Kenosha.

'Something completely different'

The skeleton was found in 2001 on an American Museum of Natural History expedition to the Gobi Desert of Mongolia. It was found at the same site as a Tarbosaurus fossil.

"It wasn't a priority for the American Museum of Natural History staff to open up; they had other things to get to," Prof. Carr said. "When they opened it up, they were expecting to see a baby tyrannosaur that's well known, but they quickly realized that it was something completely different."

Scientists in the museum's Division of Paleontology invited Prof. Carr to study the fossil because of his expertise on tyrannosaurs.

"The animal is a tyrannosaur, a meat-eating dinosaur related to T. rex," Prof. Carr said. "Its skull is very slender — much more slender than other tyrannosaurs. ... What's really cool about this dinosaur is that it has an extra set of horns on its face that no other tyrannosaur has. They stick out from the sides of the cheeks. Usually tyrannosaurs only have six horns; this one has eight horns. That's really different.

"It was beyond the pale of what has been seen before."

'Like a ballerina'

According to the Museum's press release, the skeleton is exceptionally well preserved, and sheds light on a previously poorly understood genus of tyrannosaurs.

"This spectacular fossil tells us that there is a lot more anatomical and ecological variety in tyrannosaurs than we previously thought," said Stephen Brusatte, a graduate student affiliated with the American Museum of Natural History. "Not all tyrannosaurs were megapredators adapted for stalking and dismembering large prey. Some tyrannosaurs were small and slender. Compared to Tyrannosaurus, this new animal is like a ballerina."

Prof. Carr took measurements of every bone to analyze where Alioramus altai fits on the tyrannosaur family tree, co-wrote the description of the species, and determined its age based on its features. "In terms of relative maturity, it’s a teenager," he said.

Related links:

Professor Carr featured on National Geographic Channel

Proceedings of the National Academy of Sciences: A long-snouted, multihorned tyrannosaurid from the Late Cretaceous of Mongolia

American Museum of Natural History: Bizarre New Horned Tyrannosaur From Asia ... Shared Environment With Larger Cousins

American Museum of Natural History Science Bulletins: Interactive slideshow introducing the new species