The process of evolution of modern horse from its ancestor Eohippus is elucidated in the given diagram.
As can be seen, this development took 40 million years and it had four stages in total. In the first stage, it was termed as ‘Eohippus’, which was smaller in size, with four-toed foot. After 10 million years, it transformed into ‘Mesohippus’ which was slightly larger in size than its predecessor. It had slightly thick fur on the back of its neck. A notable change occurred here was in the foot structure, where the number of toes in its foot reduced to three, with a prominent middle one. The ‘Merychippus’ evolved 15 million years ago, which was even larger in size. It had a larger foot structure.It also had thicker fur and longer tail. . The modern horse, the largest in its lineage, has a complex foot structure. Its toes gave way to a hoof, which can balance its body mass .Thick coat of longer fur on the back of its neck and tail make it look very distinct from its predecessors.
Overall, tremendous changes occurred to the modern horse throughout its evolution, with a special focus on its foot structure.
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