Hammerhead Highway: Sharks have thrived in the oceans for over 350 million years, but around 20 million years ago a new species emerged in the fossil records in a form unlike ever seen before... the Hammerhead Shark. Why did this bizarre looking creature evolve and how has it survived? Scientific evidence suggests that Hammerheads seek out distant destinations but is there a method to their travels? Threatened by declining populations the HAMMERHEAD HIGHWAY may be the key to their survival.