Equus (genus) 54 million years ago (Mya). These animals had three toes on the hind feet and four on the front feet with small hooves in place of claws, but also had soft pads.<ref name="doi10.1126/science.1105458"></ref> Equids developed into larger, three-toed animals (e.g. "Mesohippus") during the Oligocene and Miocene. From there, the side toes became progressively smaller through the Pleistocene until the emergence of the single-toed "Equus". The genus "Equus", which includes all extant equines, is believed to have evolved from "Dinohippus", via the intermediate form "Plesippus". One of the oldest species is "Equus simplicidens", described as zebra-like with a donkey-like head shape.
Australopithecus africanus and STS 71), but also presents primitive features including ape-like, curved fingers adapted to tree climbing. Instead of it being a direct ancestor of later hominins and thereby of humans, some researchers believe that "A. africanus" evolved into "Paranthropus", and specifically that "P. robustus" descended from "A. africanus". Both "P. robustus" and "A. africanus" crania seem very alike despite the more heavily built (robust) features of "P. robustus", which, like those of the modern gorilla, are adaptations for heavy chewing. "A. africanus", on the other hand, had a cranium which quite closely resembled that of a modern chimpanzee; yet both