A North American Oviraptorosaur, the second substantial specimen of its kind, was discovered by Burpee Museum of Natural History paleontology crews on BLM-administered lands near Ekalaka last July.
Burpee Museum Board Member and Highland Community College Professor, Steve Simpson and one of his students were credited with the find. Both were working an exposed section of the Hell Creek Formation in Carter County when they found claw and toe bones weathering out of a hillside belonging to a mid-sized “theropod”–a meat-eating dinosaur.
Further excavation uncovered more toe and foot bones. Within minutes, several other bones were discovered including vertebrae and ribs. The bones were disarticulated, but closely associated. About 40 bones were collected over the course of 10 days including: toe bones, metatarsals, ankle bones, tibia, partial femur, hip bones, vertebra and ribs. The bones were oriented as to be headed into the hillside and the rest of the skeleton remains covered, hopefully including the skull.
“Initially we thought this could be another juvenile tyrannosaur,” said Scott Williams, Burpee Museum director of Science and Exhibits. “But there were some features in the toe bones and in the foot bones that are different from Tyrannosaurus rex; they’re not curved as much, not as robust or stocky; the claws are also different. The kicker was the tail vertebrae. They were fairly stubby, not as elongated as what you would find in a juvenile tyrannosaur and they had pneumatic openings visible.”
Williams likened the animal to “a parrot on steroids.”
“Based on the length of its tibia and other bones we have, it’s probably going to be 5 to 6 feet tall at the hip,” said Williams. “You’re looking at an animal that is probably pretty fleet of foot, very lightly built, lots of hollow bones that have air sacs. This animal could get around pretty good.”
Oviraptorosaur means “egg thief lizard.” Paleontologists first thought these dinosaurs were nest raiders based on a Mongolian fossil of an adult sprawled on top of a clutch of eggs. Later studies concluded that the animal died upon its own nest. Several preserved specimens have since been recovered positioned in similar brooding postures. Oviraptors are thought to be omnivorous.
Artist conceptions based on existing skeletons depict an upright, ostrich-like animal with fairly long, three-fingered upper limbs and a skull that has a pronounced crest and a parrot-like beak. There are many varieties of oviraptors ranging in size from the turkey-sized Caudipteryx to the 1.4 ton Gigantoraptor. Some have crests, some don’t, and other characteristics vary. The most complete specimens have been found in Asia. North American finds are exceptionally rare.
Oviraptors have been found with impressions of well-developed feathers, particularly on the wings or hands, and tail. Well preserved oviraptor tails have evidence of developed “pygostyles” — a bony structure located at the end of the tail that supports a fan of feathers, possessed by modern birds. Quill knobs have also been found on some oviraptor specimens.
Dr. Thomas Holtz, noted paleontologist and theropod expert from the University of Maryland, arrived in Montana the day after the initial discovery and helped identify the specimen as a Caenagnathid oviraptorosaur based on the air sac spaces in its tail vertebra.
“It appears to be a large (perhaps the largest so-far) of the as-yet unnamed species of big (ostrich-sized or larger) oviraptorosaur from the very end of the age of dinosaurs in western North America,” wrote Holtz in an Aug. 19 letter to the Burpee Museum Board of Directors.
“Based on very preliminary estimates (as most of the bones were still in the ground at the time I last saw them), this individual dinosaur may be 15 to 20 percent larger than the Carnegie Museum specimen,” said Holtz. “It could be that this is simply an older and larger individual of this rare species. Alternatively, it might be a new species of the same sort…detailed examination of the bones of this new skeleton compared to those of previously discovered ones will determine this.”
The specimen has been nicknamed “Pearl” for Pearl City, Ill. and Pearl City Street, where Simpson and his students are from. Burpee field crews will return to Montana and collect the remainder of the specimen and is currently preparing “Pearl” for scientific description by Dr. Holtz.
Currently, the Carnegie Museum in Pittsburgh, Pennsylvania has the only one complete mounted North American oviraptorosaur in the world. The Carnegie specimen is the composite of two individuals and is missing its feet. Not only does “Pearl” have elements missing from the Carnegie specimen, but it is similar in size.
BLM-permitted excavation teams working on public land must be Federally-recognized repositories for paleontological specimens before they can be considered qualified to excavate on Federal lands. Permits are issued to professional paleontologists who must agree to preserve their finds in a public museum, a college, or a university because of their scientific importance. These remains must also be made available to other researchers and are held in trust for the People of the United States.
“Burpee Museum has a phenomenal track record of conducting paleontological field work under permit on public lands in southeastern Montana. One of the great things about collecting material on public lands is that the specimens, once prepared and curated, are truly available to the public,” said Williams. “Specimens like our juvenile Tyrannosaurus rex ‘Jane,’ our sub-adult Triceratops ‘Homer,’ on down to shed dinosaur teeth and fish vertebra, are available not only for the general public and school tours to enjoy; they are available to qualified researchers to study.”
Williams went on to say that when Pearl, is completely prepared “she” will be available for what he termed as the “the trifecta:” scientific study, public exhibition and educational programming. The accessibility of these specimens to the general public is incredibly important to help excite and encourage children to take an interest in science, said Williams.
“Equally important is the accessibility of specimens to qualified paleontologists,” he said. “Through their research and study we are better able to educate all people about the history of our natural world.”
“Our paleontological field successes in Montana have allowed us a wonderful opportunity to collaborate with the Bureau of Land Management as well as to maintain a great relationship with many ranchers in the Carter County area,” said Williams. “There’s a rich paleontological history in that part of Montana and I feel lucky to be able to share that with so many people.”
The Burpee Museum formally announced their discovery of this rare North American, Montana dinosaur in a Nov. 15 news release.
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