7. Deep Sea Killers

Megalodon, a 50-foot long cousin of the modern Great White Shark was considered the most dangerous predator in the 15 million year old seas. That belief held until a discovery in Japan in 1992 of a fossilized whale equipped with 44 teeth that equaled those of a Tyrannosaurus rex. Watch as experts recreate an undersea battle using modern whale and shark behaviors, and fossilized evidence to see how the two largest killers of the sea fought for supremacy.