World’s biggest animals evolved to walk on their tiptoes because it allowed them to develop stronger legs

There is a reason that many of the largest mammals, from rhinos and hippos to giraffes, walk on tiptoe, according to Daily Mail.

Starting to walk on their toes and hooves may have allowed these animals to become huge and take over the planet.

A study of 880 mammals has found many rapidly grew in size at the same time they evolved from being flat-footed to walking on tiptoes.

Unlike flat-footed mice, squirrels and humans, these animals have longer and straighter legs which support more weight and are faster, making them better predators.

The energy saved by being better runners could have helped them to grow.

Dr Manabu Sakamoto, a biological scientist at the University of Reading, said: ‘Mammals got very large very fast as they began to walk like ballerinas.

‘The tiptoed and hooved feet they developed led to the large mammals we know and love today. These animals dominate the landscape – you don’t see one-tonne, flat-footed herbivorous lizards.’

The advantages of moving on tiptoe are such that even flat-footed humans run this way.

Hooves are even better for running, which may explain why animals like deer and horses later evolved from animals which had evolved to tiptoe.

The common ancestor of all the mammals is believed to have moved on flat feet.

Researchers reconstructed on the mammal tree of life the points at which foot postures changed in history, then used a computer programme to test whether body size evolved faster at the same time. It did so, at seven times the rate seen when foot postures remained the same.

Dr Sakamoto said: ‘The research also reveals what today’s mammals have in common with dinosaurs that lived millions of years ago. Dinosaurs are the only other group in history to evolve tiptoed feet and attain giant multi-tonne sizes. This is a topic we would like to investigate next.’

The research, suggests the way the mammals moved gave them a survival advantage.

It also helped them grow, through their column-like legs supporting them better. Flat-footed animals like rats have very bendy elbows and knees which are more squat and smaller.

It would not be possible to have a mouse the size of an elephant as its limbs would break.

N.H.Kh