Wednesday, Feb 24, 2010
A team of paleontologists from Dinosaur National Monument, Brigham Young University, and the University of Michigan has announced the discovery of a new, large, plant-eating dinosaur, Abydosaurus mcintoshi (pronounced Ab-id-o-saurus mak-in-toshi). The discovery is described this week in the on-line first section of the science journal Naturwissenschaften.
The fossil remains were excavated from the 105-million-year-old Cedar Mountain Formation in Dinosaur National Monument. The new find contains rare and spectacular fossils, including the only complete sauropod skull in the entire Western Hemisphere from the last 80 million years of the Age of Dinosaurs.
“Because skulls are made up of many thin and fragile bones they are easily destroyed and rarely preserved. So although more than 120 species of sauropods have been discovered across the globe, complete skulls are extremely rare,” says Dr. Dan Chure, park paleontologist. “However, skulls are complex structures that provide a great deal of information about the dinosaur’s biology and evolution, so they are extremely important. You can hardly overstate the significance of these fossils.”
“Discovering a complete sauropod skull is remarkable. I've been collecting dinosaurs since the age of 14, and these complete skulls are the most spectacular fossils I've had the opportunity to work on,” says BYU researcher Brooks Britt. “All the Abydosaurus fossils we have collected to date are juveniles, only a mere 25 feet or so in length. How large a fully adult individual was is unknown but it was certainly much larger. Although we haven’t found a complete skeleton yet, hope springs eternal in paleontology and we will continue excavations this summer.”
University of Michigan researcher Jeff Wilson and his graduate student John Whitlock studied the feeding adaptations of Abydosaurus.
“Sauropods, one of the most diverse and long lived lineages of dinosaurs, are surprising in that they show none of the adaptations seen in other plant-eating dinosaurs, such as beaks for slicing or cheeks to hold in food while chewing,” says Wilson. “Yet in spite of the lack of any specializations, they were around for 150 million years and are the largest land dwelling animals in the history of life.”
“Abydosaurus is from a time period when titanosauriform sauropods began to develop a slimmer tooth shape from the broader teeth of their ancestors,” adds Whitlock. “This change in tooth shape is related to changes in diet in a way we are only just beginning to understand, in part because we haven't always had the fossils to tell the whole story. Abydosaurus is the right dinosaur at the right time to answer some of these questions."
This announcement is the result of a several years of research, beginning with excavations started in the late 1990s. The site contains not just one individual but the remains of a group of sauropods – at least four individuals and likely more since additional fossils are still in the ground. Most parts of the skeleton are present, including neck and tail vertebrae, shoulder blades, pelvis, arms, legs, hands, feet, and four skulls – two complete and two incomplete.
The excavation and preparation of this new dinosaur’s remains has been a collaborative effort among the National Park Service, volunteers, students, paleontologists, academic institutions, CESU members, and outside researchers. The new fossils are being prepared and stored at the Paleontology Museum at Brigham Young University in Provo, Utah.
Abydosaurus mcintohsi is described in Chure, D.J., Britt, B.B., Whitlock, J., and Wilson, J.S. 2010. “First Complete Sauropod Dinosaur Skull from the Cretaceous of the Americas and the Evolution of Sauropod Dentition.” Naturwissenschaften. A copy of the paper is freely available and can be downloaded at http://www.springerlink.com/content/100479/.