How can the tracks of dinosaurs best be interpreted and used to reconstruct them? In many Mesozoic sedimentary rock formations, fossilized footprints of bipedal, three-toed (tridactyl) dinosaurs are preserved in huge numbers, often with few or no skeletons. Such tracks sometimes provide the only clues to the former presence of dinosaurs, but their interpretation can be challenging: How different in size and shape can footprints be and yet have...