Apparently, our official state dinosaur is an impostor.
Bones discovered in the 1990s that spurred the Legislature to declare the pleurocoelus the state's official dinosaur were misidentified and actually came from a different species, according to a student's research.The findings of Peter Rose, a former graduate student at Southern Methodist University, were published recently in "Palaeontologia Electronica," an online journal of the Society of Vertebrate Paleontology.
Mainstream scientists have been quick to accept Rose's findings, said Louis Jacobs, a professor of geological science at SMU.
"I'm one of those ones who presumed the bones were pleurocoelus, and now I'm convinced he is right," said Jacobs, adding that the new species should be promoted to Official Dinosaur of Texas.
Rose studied the bones for three years as part of his master's thesis. His comparison of the bones with a pleurocoelus (pronounced pluro-SEE-lus) specimen at the Smithsonian Institution revealed that the leg and shoulder bones were significantly different.
He named the previously unknown species the paluxysaurus (pronounced pah-luxy-sah-rus), because the bones were found near the Paluxy River.
"I wasn't going in with any assumptions. I thought that what I was looking at was the pleurocoelus," said Rose, 28, who is now a graduate geology student at the University of Minnesota.
"But in the process of describing the bones, I came to the conclusion that it had to be something really different."
Scientists believe the pleurocoelus was a plant-eater that lived in what is now Central Texas 110 million years ago. They thought the giant creature, which was up to 60 feet long and weighed up to 45 tons, was the only dinosaur of it size in North America during that period.
Rose said the discovery of a new species means there was more diversity among dinosaurs of that period than was previously thought.
Jacobs said the original identification of the bones was based more on assumption than systematic study. The bones were covered in limestone, making them difficult to identify.
"They couldn't see the bones very well, and they assumed that anything of that size and age had to be pleurocoelus," Jacobs said.
The bones are now in the possession of the Fort Worth Museum of Science and History, where they were on display as the remains of a pleurocoelus. The museum is currently renovating the display, and the bones will be identified as paluxysaurus when it's reopened in 2009, said Charlie Walter, the museum's chief operating officer.
Walter said the museum will petition the Legislature to designate the paluxysaurus as the state's rightful official dinosaur.