Sample Detail

The picture details the 4 evolutionary phases of the horse over the course of 40 million years and it focuses on how the toes on earlier horses transformed into the hoof that we are familiar with today. Looking at the diagram, it is immediately clear that the size of the horse grew formidably and the modern horse is significantly larger than its ancestors. Regarding its foot structure, the most noticeable transformation is the gradual disappearance of the toes found in prehistoric horses. The earliest horse examined lived 40 million years ago and its scientific name is Eohippus. It is noticeably furrier than its descendant Mesohippus which reportedly lived 30 million years ago. All of the hair on its body seems to have disappeared at this point, and it starts to show some semblance of a mane. The horse found 15 million years later called Merychippus has a more erect posture, and its mane looks more fully formed. Nowadays, the horse is considerably taller, larger and more muscular, with a lot more hair in the tail and the mane. The foot structure of the horse has exhibited similarly remarkable changes. The foot of the Eohippus is quite slender and has 5 distinct toes. The one found in Mesohippus only has 3, which is the same number of toes that the later horse Merychippus has, although that of the latter is much larger in size with a prominent middle toe. The modern horse, however, has only one hoof and much more developed joints.