Friday, March 19, 2010

New Raptor Discovered

George Washington University Doctoral Candidate and University College London Grad Student Discover New Species of Raptor Dinosaur

Near Complete Skeleton Will Help Further Describe Pre-Historic Relatives

WASHINGTON – A new species of raptor dinosaur being named "Linheraptor exquisitus" has been discovered by George Washington University doctoral candidate Jonah Choiniere and Michael D. Pittman, a graduate student at University College London (UCL). The exceptionally well-preserved, nearly complete skeleton is a relative of the well-known species "Velociraptor," and will help scientists further describe the physical appearance of other closely-related dinosaurs within the Dromaeosauridae family. The research, led by Xu Xing of the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology, will be published in the March 19, 2010, issue of "Zootaxa."

“I only saw the tip of the claw sticking out of a cliff face, and it was a total surprise that the whole skeleton was buried deeper in the rock,” said Mr. Choiniere. “This fossil is going to tell us a lot about the evolution of the skeleton in the group that includes 'Velociraptor'.”

At approximately eight feet long and 50 pounds, the researchers believe "Linheraptor" would have been a fast, agile predator that preyed on small horned dinosaurs related to "Triceratops." Like other dromaeosaurids, it possessed a large, highly curved claw on the foot, which may have been used to capture prey. Within the Dromaeosauridae family, "Linheraptor" is most closely related to another recently discovered species "Tsaagan mangas." The head and neck of the "Tsaagan" skeleton was discovered in Mongolia in 1993 by James Clark, the Ronald B. Weintraub Professor of Biology at The George Washington University's Columbian College of Arts and Sciences. "Tsaagan’s" skull indicates that it is more primitive than "Velociraptor," and the skeleton of the new species should help reconstruct the series of evolutionary changes within the Dromaeosauridae.

“This is a really beautiful fossil and it documents a transitional stage in dromaeosaurid evolution,” said Dr. Xu.

"Linheraptor" was found by the researchers in approximately 75 million year-old red sandstone rocks during a 2008 field expedition in Inner Mongolia, China. It is the fifth dromaeosaurid discovered in these rocks, which are famous for their preservation of uncrushed, complete skeletons. These red sandstones are best known from the Flaming Cliffs field site in outer Mongolia, the location where "Velociraptor" was discovered and dinosaur eggs and nests were first found.

“The original 'Tsaagan' find was very intriguing, and this discovery should really help us flesh out what these animals looked like,” said Dr. Clark.

Dromaeosauridae is a family of bird-like theropod dinosaurs that lived during the Cretaceous Period. In addition to "Linheraptor" and "Velociraptor," theropod dinosaurs include charismatic meat-eaters like "Tyrannosaurus rex" and modern birds.

This research was funded by the U.S. National Science Foundation and the Chinese National Science Foundation, the Jurassic Foundation, the Geological Society of London and The George Washington University.

Mr. Choiniere is a doctoral student of Dr. Clark’s and first accompanied Dr. Clark on his excavations in China in 2005. Though this discovery is Mr. Choiniere’s first significant fossil find, he was the lead author of the recent "Science" article, “A Basal Alvarezsauroid Theropod from the Early Late Jurassic of Xinjiang, China.” Mr. Pittman is a doctoral student of Dr. Paul Upchurch and Dr. John R. Hutchinson and has worked with Chinese scientists since 2006.

The article, “A new dromaeosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China,” appears in the March 19, 2010, issue of "Zootaxa." "Zootaxa" is an international journal for animal taxonomists.

Photo above: Velociraptor model