EKALAKA, Mont. | Another major dinosaur fossil has been found in southeastern Montana, not far from the Belle Fourche area.
A North American oviraptorosaur, the second substantial specimen of its kind, was discovered by Burpee Museum of Natural History paleontology crews on BLM-administered federal land near Ekalaka, Mont.
Ekalaka is northwest of Belle Fourche in Carter County, Mont., across the state line from Butte County.
It's also an area where many major dinosaur fossils have been discovered through the years.
According to a news release from the Bureau of Land Management office in Miles City, Burpee Museum Board Member Steve Simpson, who also is a Highland Community College professor, and one of his students are credited with the discovery.
They 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, which is 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 not connected, but were found near each other.
About 40 bones were collected over 10 days, including toe bones, metatarsals, ankle bones, tibia, partial femur, hip bones, vertebra and ribs. The rest of the skeleton remains covered. Paleontologists hope that the fossil skeleton eventually will include 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," he said. "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,” he said.
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,” Williams said. “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 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 a bony structure at the end of the tail that supports a fan of feathers similar to modern birds. Quill knobs have also been found on some oviraptor specimens.
Dr. Thomas Holtz, 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 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,” Holtz wrote in an Aug. 19 letter to the Burpee Museum board of directors.
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 to collect the remainder of the specimen.
Currently, the Carnegie Museum in Pittsburgh has the only complete mounted North American oviraptorosaur in the world. The Carnegie specimen is a 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.
Williams said that when Pearl is prepared “she” will be available for scientific study, public exhibition and educational programming.