Dinosaur tracks show walking and running
By Sid Perkins
A single trail of dinosaur footprints in a quarry northwest of London preserves a record of two different walking styles in the same animal, a tantalizing clue that some lumbering, bipedal dinosaurs could also run.
The trail of three-toed imprints is in a 163-million-year-old layer of white limestone. The footprints were probably made by a Megalosaurus, a 9-meter-long, meat-eating dinosaur first described in 1826, says Julia J. Day, a paleontologist at the University of Cambridge in England.