The Role of Circular and Spherical Objects in Nature

Largest creatures alive today are mammals, but the biggest one is a blue whale. The way that dinosaurs fed was to take in huge amounts of food without chewing. Their digestion worked on just a different kind of scale to anything we currently see. There's nothing like a wheel because you've got to solve the problem of how you get a blood supply - but there are gears in nature. A paper published last year has discovered in the back legs of an insect, there isn't a wheel, but there're gears and it means they jump accurately.