Horned Dinosaur Pelvic Bone Points to a Utah Original

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Lying bones tell no lies and the truth being whispered from a hip bone of a young horned dinosaur found in Utah’s San Rafael Swell is that its origin and age may not be what scientists previously thought.
Sorry Central Asia, but North America, Utah in particular, may actually have bragging rights to this distant relative of Triceratops, according to Kenneth Carpenter, director and curator of paleontology at Utah State University Eastern Prehistoric Museum.
It appears that these horned dinosaurs were roaming Utah’s ancient sea shores around 98 million years ago ? some 8 million years prior to the ones found in Uzbekistan and New Mexico, according to Carpenter in a paper recently published in the science journal “Cretaceous Research,” and co-authored by Richard L. Cifelli, curator of vertebrate paleontology with the Oklahoma Museum of Natural History.
“Prior to this discovery, it was a toss-up as to whether they originated in the United States or Central Asia because advanced horned dinosaurs of the same age were found in both places,” Carpenter says. “This specimen pushes the evidence towards a North American origin and from here migrating across an ancient Bering land bridge to Asia.”
It means, that at least for now, Utah can claim more than 71 species of dinosaurs, of which 28 are unique to the Beehive state, the most famous of these being the Utahraptor, Carpenter says.
Cifelli had previously found in Montana a little skull of a small ceratopsian related to Protoceratops in rock roughly the same age. That dinosaur was named Aquilops. Its discovery was not so unexpected because it fit in the early evolutionary scheme of ceratopsians, and was even the right age, Carpenter says.
“The Utah pelvic bone, however, is totally surprising because it shows the presence of an even more advanced ceratopsian, and so it was not what was expected,” Carpenter says. “It is like finding a Boeing 747 in a Da Vinci drawing.”
While intact skeletons are always the preference, scientists have learned to make due with whatever is left them. In this particular case, the Utah native horned dinosaur left behind a pelvic bone that provided many clues to its species and age, specifically characteristics of immature bone that closely resembled the ilium of a ceratopsid Agujaceratops, Carpenter says.
The ancient bone measures a little over 10 inches long. It was found by Nick Czaplewski in 1991 during the first complete field season in the Cedar Mountain Formation by parties from the Oklahoma Museum of Natural History. It was discovered among the bones of long-ago fish, turtles and crocodiles between volcanic ash beds southwest of the San Rafael Swell in the Mussentuchit Wash area, Carpenter says.
Carpenter first became interested in analyzing this single bone ever since he first saw it in the OU museum collections 10 years ago. He knew then that it belonged to a ceratopsian. But it wasn’t until a year ago that he had the time to describe it. He and Cifelli spent about 11 months in research and writing before publishing the paper in late December.
The main significance of this find is that it supports the hypothesis that this group of dinosaur inhabited the earth during the earliest Late Cretaceious period, which means it had a longer history in North America than previously thought, Carpenter says.
In late January, Carpenter published another paper in which he helped to name a new genus of stegosaur showing that the dinosaurs of the Jurassic period were far more diverse than what scholars previously thought.
The truth these bones utter about time, history and diversity, combine to provide scientists greater clarity of what life was like on earth millions of years ago, including some of Utah’s earliest residents, Carpenter says.