New Find is Evolutionary Link Between Ceratopsians and Pachycephalosaurs, the “Bone-Headed” Dinosaurs

James M. Clark, Ronald B. Weintraub Associate Professor of Biology at The George Washington University, and Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, have discovered the oldest-known ceratopsian, a finding that solidifies the close evolutionary evidence between ceratopsians and pachycephalosarians, the “bone-headed” dinosaurs. Roaming the earth 160 million years ago, the new basal ceratopsian dinosaur, Yinlong downsi, appeared 20 million years earlier than the previous oldest ceratopsian and 85 million years earlier than the best known ceratopsian, Triceratops. >> READ

Clark's paper in Proceedings of the Royal Society B: Biological Sciences "A Basal Ceratopsian with Transitional Features from the Late Jurassic of Northwestern China" >> READ

Clark's Web Site


GW BIOLOGY PROFESSOR DISCOVERS SKELETONS OF OLDEST TYRANNOSAUR

James M. Clark, Ronald Weintraub Associate Professor of Biology at The George Washington University, has unveiled a significant discovery of a new genus and species of dinosaur that is the oldest known and most primitive tyrannosauroid.

The new basal tyrannosauroid sheds new light on the early evolution of coelurosaurs, small theropod dinosaurs including the closest relatives of birds. The discovery is detailed by Clark, Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, and six colleagues in a paper titled “A Basal Tyrannosauroid Dinosaur from the Late Jurassic of China,” that appears in the Feb. 9, 2006, edition of the science journal Nature. MORE >>

Clark's PowerPoint Presentation
Clark's Paper in Nature
Nature Podcast
Newsroom
Discovery Channel Video

Photo Credit: James M. Clark
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Yinlong downsi skeleton
Photo Credit: IVPP
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Guanlong wucaii - artist rendering
Photo Credit: Zhongda Zhang, IVPP
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Guanlong wucaii skull
Photo Credit: IVPP
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Guanlong wucaii skull rendering
Photo Credit: R.S. Li, IVPP
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