February 24, 2010

New Dinosaur Species Discovered

Two complete skull fossils from sauropods were found at Dinosaur National Monument, scientists announced on Tuesday.

Parts of this extremely rare find had to be freed with explosives, due to the hard Utah sandstone in which they were incased. The bones were from long-necked, plant-eating sauropods, which were the biggest animals known to have lived on land, reported the Associated Press.

The find provides more information about the lives of dinosaurs some 105 million years ago, including the evolution of sauropod teeth that reveals how they ate and other information, said Dan Chure, a paleontologist at the monument that straddles the Utah-Colorado border.

"You can hardly overstate the significance of these fossils," he told AP.

There are 120 or so known species of sauropods, but only eight complete skulls have been accounted for. Researchers believe that this is likely because their skulls were comprised of thin, fragile bones held together with soft tissue that were easily destroyed after death.

"This is absolutely No. 1 in terms of projects I've had the opportunity to work on," said Brooks Britt, a Brigham Young University paleontologist who co-authored a study on the fossils along with University of Michigan researchers.

The new species, Abydosaurus McIntosh, is part of the larger brachiosaurus family of huge four-legged vegetarians that include sauropods, said researchers.

The peer-reviewed science journal Naturwissenschaften will publish the findings this week.

The bones were lodged in a quarry called DNM 16. The quarry was originally found in 1977, but extensive excavations did not begin until the late 1990s.

The skulls were found in 2005. Tantalized researchers, though, were stymied by rocks around the bones that were so hard that workers were unable to break through, even with use of a jackhammers and concrete saws.

Last year, the rocks were loosened by a Rocky Mountain National Park crew in Colorado as they spent three days detonating handset explosives without harming the bones. Scientists were then able to uncover other fossils, including leg bones, shoulder blades and other parts.

At least four dinosaur remains are likely at that site, according to paleontologists. Britt said they all appear to be juveniles around 25 feet long.

"We don't know how much bigger they could get," Britt said.

Scientists are also interested in what the skulls can teach them about how the sauropods ate their food.

"They didn't chew it. They just grabbed it and swallowed it," Britt said.

Earlier sauropods chewed with broad teeth, while later versions had narrow, pencil-like teeth. The abydosaurus teeth are mid-sized, giving scientists an idea of how their eating techniques and diet changed over time.

"Abydosaurus is the right dinosaur at the right time to answer some of these questions," University of Michigan researcher John Whitlock said in a statement.

The find may be the most complete view to date of certain sauropods roaming North America from the Lower Cretaceous period spanning roughly 145 million to 99 million years ago, said Jim Kirkland, Utah's state paleontologist, who was not involved in the discovery announced Tuesday.

The fossils can be seen at BYU's Museum of Paleontology, where they are temporarily on display.


Image 1: BYU geology professor Brooks Britt. Credit: BYU

Image 2: BYU student Ashley Scheetz preparing an Abydosaurus jaw. Credit: BYU

Image 3: Artist impression of Abydosaurus McIntosh by Michael Skrepnick


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