|Utahceratops (above) and Kosmoceratops (below).|
© Lukas Panzarin
For those of you who have seen the various talks, and specifically the new paper in the recently published in 'New Perspectives on Horned Dinosaurs' (Getty et al. 2010), referring to these animals as "Kaiparowits New Taxon A" and "Kaiparowits New Taxon B" you will be happy to know that Taxon A is Kosmoceratops and Taxon B is Utahceratops. At least three individuals (an adult and two subadults) of Utahceratops were recovered from one monodominant bonebed, the first of its kind in the Kaiparowits Formation.
Chasmosaurus irvinensis is also addressed and renamed Vagaceratops irvinensis (“wandering horned face”) in this paper, as it was found to share closest affinities not with Chasmosaurus, as originally believed, but with Kosmoceratops. The study has helped to show that there is some sort of northern and southern provincialism taking place during the Campanian stage of western North America, also known as Laramidia [read more here]. Both specimens are curated at the Utah Museum of Natural History in Salt Lake City, Utah, and are currently on display for the rest of this year.
Sampson, S. D., M. A. Loewen, A. A. Farke, E. M. Roberts, C. A. Forster, J. A. Smith, and A. L. Titus. 2010. New horned dinosaurs from Utah provide evidence for intracontinental dinosaur endemism. PLoS ONE 5(9): e12292. doi:10.1371/journal.pone.0012292
Getty, M.A., M.A. Loewen, E. Roberts, A. L. Titus, and S.D. Sampson. 2010. Taphonomy of Horned Dinosaurs (Ornithischia: Ceratopsidae) from the Late Campanian Kaiparowits Formation, Grand Staircase-Escalante National Monument, Utah. Pp. 478-494 in M. J. Ryan, B. J. Chinnery-Allgeier, and D. A. Eberth (eds.), New Perspectives on Horned Dinosaurs. Indiana University Press, Bloomington.
From the official press release:
Amazing Horned Dinosaurs Unearthed on “Lost Continent”
Discoveries Include Bizarre Beast with 15 Horns
September 22, 2010 – Two remarkable new species of horned dinosaurs have been found in Grand Staircase-Escalante National Monument, southern Utah. The giant plant-eaters were inhabitants of the “lost continent” of Laramidia, formed when a shallow sea flooded the central region of North America, isolating the eastern and western portions of the continent for millions of years during the Late Cretaceous Period. The newly discovered dinosaurs, close relatives of the famous Triceratops, were announced today in PLoS ONE, the online open-access journal produced by the Public Library of Science.
The study, funded in large part by the Bureau of Land Management and the National Science Foundation, was led by Scott Sampson and Mark Loewen of the Utah Museum of Natural History (UMNH) and Department of Geology and Geophysics, University of Utah. Additional authors include Andrew Farke (Raymond Alf Museum), Eric Roberts (James Cook University), Joshua Smith (University of Utah), Catherine Forster (George Washington University), and Alan Titus (Grand Staircase-Escalante National Monument).
|Image of Utahceratops from "The Whirlpool of Life"|
|Image of Kosmoceratops from "Scratching the Surface"|
Although much speculation has ensued about the function of ceratopsian horns and frills—from fighting off predators to recognizing other members of the same species or controlling body temperature—the dominant idea today is that these features functioned first and foremost to enhance reproductive success. Sampson added, “Most of these bizarre features would have made lousy weapons to fend off predators. It’s far more likely that they were used to intimidate or do battle with rivals of the same sex, as well as to attract individuals of the opposite sex.”
Monumental Dinosaurs on a Small Continent
The dinosaurs were discovered in Grand Staircase-Escalante National Monument (GSENM), which encompasses 1.9 million acres of high desert terrain in south-central Utah. This vast and rugged region, part of the National Landscape Conservation System administered by the Bureau of Land Management, was the last major area in the lower 48 states to be formally mapped by cartographers. Today GSENM is the largest national monument in the United States. Sampson added that, “Grand Staircase-Escalante National Monument is now one of the country’s last great, largely unexplored dinosaur boneyards.”
For most of the Late Cretaceous, exceptionally high sea levels flooded the low-lying portions of several continents around the world. In North America, a warm, shallow sea called the Western Interior Seaway extended from the Arctic Ocean to the Gulf of Mexico, subdividing the continent into eastern and western landmasses, known as Appalachia and Laramidia, respectively. Whereas little is known of the plants and animals that lived on Appalachia, the rocks of Laramidia exposed in the Western Interior of North America have generated a plethora of dinosaur remains. Laramidia was less than one-third the size of present day North America, approximating the area of Australia.
Most known Laramidian dinosaurs were concentrated in a narrow belt of plains sandwiched between the seaway to the east and mountains to the west. Today, thanks to an abundant fossil record and more than a century of collecting by paleontologists, Laramidia is the best known major landmass for the entire Age of Dinosaurs, with dig sites spanning from Alaska to Mexico. Utah was located in the southern part of Laramidia, which has yielded far fewer dinosaur remains than the fossil-rich north. The world of dinosaurs was much warmer than the present day; Utahceratops and Kosmoceratops lived in a subtropical swampy environment about 100 km from the seaway.
|Distribution of ceratopsians during the Campanian|
stage of the Late Cretaceous period
During the past decade, crews from the University of Utah and several partner institutions (e.g., the Utah Geologic Survey, the Raymond Alf Museum of Paleontology, and the Bureau of Land Management) have unearthed a new assemblage of more than a dozen dinosaurs in GSENM. In addition to Utahceratops and Kosmoceratops, the collection includes a variety of other plant-eating dinosaurs—among them duck-billed hadrosaurs, armored ankylosaurs, and dome-headed pachycephalosaurs—together with carnivorous dinosaurs great and small, from “raptor-like” predators to mega-sized tyrannosaurs (not T. rex but rather its smaller-bodied relatives). Also recovered have been fossil plants, insect traces, clams, fishes, amphibians, lizards, turtles, crocodiles, and mammals, offering a direct glimpse into this entire ancient ecosystem. Most remarkable of all is that virtually every identifiable dinosaur variety found in GSENM turns out to be new to science, offering dramatic confirmation of the dinosaur provincialism hypothesis. Many of these animals are still under study, but two have been previously named: the giant duck-billed hadrosaur Gryposaurus monumentensis and the raptor-like theropod Hagryphus giganteus.
Utahceratops and Kosmoceratops are part of a recent spate of ceratopsian dinosaur discoveries. Andrew Farke, another of the paper’s authors, stated, "The past year has been a remarkable one for horned dinosaurs, with several new species named. The new Utah creatures are the icing on the cake, showing anatomy even more bizarre than typically expected for a group of animals known for its weird skulls."
Clearly many more dinosaurs remain to be unearthed in southern Utah. “It’s an exciting time to be a paleontologist,” Sampson added. “With many new dinosaurs still discovered each year, we can be quite certain that plenty of surprises still await us out there.”
© ReBecca K. Hunt-Foster unless other wise noted