The illustration above shows the fossils of the front foot bones and teeth of four different species of horse. the present day horse, equus is seen on the right. it has much larger teeth adapted for grazing on tough leaves and grasses. the changes in horses over the last 55 million years are shown in these fossils as well. early horses were adapted to living in wooded swampy areas where more toes were an advantage. also, the early horse was small and had teeth that were adapted to browsing on young shoots of trees and shrubs. the single hoofed toe of the present day horse allows it to travel fast on the plains. the foot bones at the upper right of each diagram (black) indicate the relative bone sizes of each kind of horse. x=toe bones, y= foot bones, w= ankle bone, z= heel bone which species of horse would have a preserved fossil found in the deepest layer compared to the others? a) equus b) hyracotherium c) merychippus d) miohippus