In July, the scientists from the University of Alaska Museum of the North embarked on a 500-mile (800 kilometers) journey down the Tanana and Yukon rivers; they brought back 2,000 pounds (900 kilograms) of dinosaur footprint fossils.
Lots of Tracks
Tracks at every outcrop
"We found dinosaur footprints by the scores on literally every outcrop we stopped at," McCarthy, of the University of Alaska Fairbanks, said in a statement. "I've seen dinosaur footprints in Alaska now in rocks from southwest Alaska, the North Slope and Denali National Park in the Interior, but there aren't many places where footprints occur in such abundance."