Dromaeosauridae is a diverse family of predatory (carnivorous) dinosaurs with a plethora of species that have been discovered within the last two decades and a few that were known previously. The three newly discovered species were found at two nearby dinosaur sites: Doelling’s Bowl Bone Bed and Andrew’s Site.
One of the species is designated the holotype of the new genus and species Yurgovuchia doellingi. The species name honors Helmut Doelling in recognition of his more than 50 years of geological research and geological mapping of Utah for the UGS. Y. doellingi was found in Doelling’s Bowl Bone Bed; an extensive and important dinosaur site that was first discovered as a result of Doelling providing taped-together color photocopies of his then-unpublished geological maps of the Arches National Park region to an unknown young paleontologist named Jim Kirkland in 1990. This map revealed a number of unexplored areas resulting in the discovery of this important dinosaur bone bed. The locality is particularly important as it sits below a marker bed that had formerly been used to mark the base of the Cretaceous and is thus older than previously studied Lower Cretaceous dinosaur sites in the area.
Dromaeosaurids are remarkable for the presence of an enlarged, recurved claw on the second toe that may have functioned as a predatory weapon, a weapon for finding its place in the pack’s pecking order, a climbing aid, a digging tool, or a combination of functions. Several species from China are covered in birdlike feathers and closely related to birds; thus dromaeosaurids are important in studies of the origin of avian flight.
Body sizes in the family have a large range from about the size of a mockingbird (four-winged Microraptor) to the largest size of a bear (Utahraptor). Yurgovuchia doellingi — which appears to have been a smaller, perhaps ancestral relative of the giant primitive dromaeosaur Utahraptor — was about the size of a coyote. The genus name is derived from the Ute word yurgovuch, meaning “coyote,” a predator of similar size to Y. doellingi that currently inhabits the same region.
Y. doellingi was initially discovered in 2005 by UGS paleontologist Don DeBlieux when he found the partial vertebral column and part of the pelvis. A second species is represented by a part of the pelvis and a possibly-associated arm bone. Simultaneously, UGS State Paleontologist James Kirkland and UGS paleontologist Scott Madsen were investigating other skeletal remains in nearby areas and all three sites were later found to be portions of the same extensive bone bed larger than that of Dinosaur National Monument.
The third species, found a few miles to the west at Andrew’s Site (in honor of Andrew Milner, paleontologist at the St. George Dinosaur Discovery Site at Johnson Farm), consists of a tail skeleton that is unique among known Cedar Mountain dromaeosaurids. This tail is distinctive in the long extensions of bone off of each vertebrae stiffing the tail as a balancing organ. Although not providing enough information to permit the species to be properly defined, the fossil proves that there were more advanced dromaeosaurs like Velociraptor and Deinonychus living in the same habitats as the giant but more primitive Utahraptor.
Excavation of the Doelling’s Bowl Bone Bed has been conducted under Bureau of Land Management excavation permit # UT06-035E. Excavation of Andrew’s Site Dinosaur Quarry was conducted under Bureau of Land Management excavation permit # UT-EX-05-031 under the supervision of Jennifer Cavin (currently at John Day Fossil Beds National Monument).