How did the parts of allosaurus body affect in life?

I can't explain every last bit of an Allosaurus's Biology, but I can explain the use of some of its basic external parts. The legs allowed it to walk and run, and the tail helped to keep the Allosaurus balanced so that it wouldn't tip forward. The torso, of course, held most of the essential internal organs. The arms, complete with clawed hands, could cling onto prey and prevent it from escaping. The head obviously housed the brain and the jaws, complete with serrated teeth, were used not just for eating but for killing prey. There was a crest above each eye, and these may have been colorful in life. If they were, they were probably used by males as a display to attract mates.