(London Daily Mail) Imagine a world with giant snakes as long as buses that are so fat that they can only just squeeze through the door.

Turtles the size of SmartCars would hunt crocodiles, while horses as small as cats could be found roaming fields.

This was Earth around 55 million years ago, according to U.S. researchers who have been studying the link between the size of animals, reptiles and a change in climate.

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