145 million years ago a young adult Allosaurus met sudden death. This Walking with Dinosaurs special (also called " The Ballad of Big Al ") visits the Jurassic age as scientists recreate the life of Big Al, whose nearly complete fossilized skel eton was found in Wyoming in 1991. "Big Al Uncovered" describes how scientists reached their conclusions about this carnivorous dinosaur’s life. Narrator Kenneth Branagh. BBC. Closed captioned.