‘s environment may have provided sufficient carrion for the giant to survive as a scavenger, and studies of its ratio of leg-muscle mass to body mass suggest that it wasn’t speedy enough to be an efficient predator. But this may be only how it ended its life. It didn’t hatch from the egg as a lumbering giant but, probably, as a very swift and agile killer of anything smaller. The youthful, medium-size
may have been the fastest and most fearsome Cretaceous predator. Only in the end would the beasts be sluggish but domineering scavengers.