A new member of the family of animals that were the largest ever to walk the Earth has been discovered at Dinosaur National Monument.
Scientists from Utah's Brigham Young University and the federal preserve that spans northeastern Utah and northwestern Colorado announced last week the identification of Abydosaurus mcintoshi, a species of long-necked, plant-eating sauropod dinosaur.
The circumstances of its discovery were both unusual and dramatic.
The researchers stumbled on four skulls in a quarry at the preserve. Two were still intact.
Sauropod skolls are rarely found in the fossil record because the soft tissue from which they are constructed is unlikely to be preserved after death.
“Their heads are built lighter than mammal skulls because they sit way out at the end of very long necks,” Brooks Britt, a BYU paleontologist said in a news release. “Instead of thick bones fused together, sauropod skulls are made of thin bones bound together by soft tissue."
Of more than 120 known species of sauropods, there have been only eight instances in which scientists have been able to recover intact skulls.
The fossils, which were unearthed at Cedar Quarry in the western part of Dinosaur National Monument, is the first-ever discovery of an intact sauropod skull in the western hemisphere.
Removal of the fossils also required the use of explosives.
While scientists and students did employ jackhammers and saws to cut through rock and remove the remains, National Park Service personnel had to blast away the upper layers of the 105-million year old bed of hardened sandstone.
The species, which lived during the Cretaceous period, most likely did not chew the plant material consumed.
Instead, the plants would have been broken down in the animal's stomach by means of stones called gastroliths.
Although its eating habits weren't much different from its Jurassic period predecessors, Abydosaurus' teeth were.
There were more of them and they were smaller, which indicates that an animal of the species experienced tooth replacement more than its Jurassic ancestors did.
The species' dentition is consistent with the evolutionary pattern seen in other sauropod species before they went extinct, along with other non-avian dinosaurs, at the end of the Cretaceous period.
Scientists expect that the Abydosaurus skulls will provide substantial new insights into the eating behavior of sauropods.
The skulls are on display at BYU's Museum of Paleontology.
The species' generic name, Abydosaurus, refers to the Greek city along the the Nile fomerly known as Abydos. There, according to legend, the head and neck of the Egyptian god of the underworld was buried.
The specific name mcintoshi honors the American paleontologist Jack McIntosh. In 1975 McIntosh debunked the myth of the sauropod Brontosaurus and clarified that the animal that had been known by that moniker was actually a sauropod called Apatosaurus.
Britt is a co-author on the discovery paper, which appears in Naturwissenshaften. The lead author is National Park Service paleontologist Daniel Chure. University of Michigan researchers John Whitlock and Jeffery Wilson are also co-authors.
Comments