How did whales become so large? Scientists dive into marine mystery

Changes in food distribution and not falling ocean temperatures could hold key to shift towards giant lengths

The blue whale has a body the length of a jet airliner, a heart the size of a car, and a tongue the same weight as an elephant.

Now researchers say they might have solved the mystery of why baleen whales - a group that includes these blue beasts, the largest animals on the planet - became so large.