Korean Dinosaur's Lakeside Run Preserved

June 24, 2008 -- Sometime between 145 and 100 million years ago, a Korean dinosaur ran nearly 11 miles per hour in a straight line next to a lake, according to recent study of footprints left behind by the speedy raptor.

Paleontologists believe the tracks were made by a small dromaeosaurid, which was a carnivorous Velociraptor-like dinosaur. In Greek, the word dromaeosaurid fittingly means "running lizard."

The tracks are quite rare, as they represent the first didactyl, or two-toed, raptor footprints from Korea. Such footprints are only known from two other sites in the world, both in China.

The running dromaeosaurid might have been trying to escape an even larger carnivorous dino, but the researchers can't be certain.

"It was a fast animal, but we do not know if it was influenced by other animals in its behavior," co-author Martin Lockley told Discovery News.

Lockley, a professor of geology and curator of the University of Colorado at Denver Fossil Footprint Collection, and his colleagues found the dinosaur's footprints while working at the Haman Formation on Chu Island in Korea. This is an extremely small island, only about 0.2 miles in length.

The footprints they found consist of two toes per print. Each digit has four attached, concentric pads terminated by a very prominent and sharp raptorial claw.

"This strongly curved and sharp claw was held off the ground surface in normal locomotory situations in order to prevent the ungual from becoming dull with repeated contact against an abrasive substrate, strongly suggesting that it had an offensive function, such as attacking prey," Lockley and his colleagues wrote in a paper summarizing their finds that was recently published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.

Aside from revealing that the dinosaur was in too big of a hurry to kick with its destructive claws, the footprints indicate the animal's hip height, which the researchers calculated as being about 27.5 inches.

Lockley explained that prior research determined "hip height is about five times the footprint length." Speed can then "be calculated from hip height and stride length."