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.
Equus publicus a property value of more than 100,000 denarii or else inheritance, but the equus publicus was only attainable by way of inheritance from a father. In imperial times, after the reforms of Augustus, the status could be granted by an emperor, along with inheritance from a father. Equus publicus The Equus publicus (literally "horse bought by the commonwealth") was an honourable status in ancient Rome, granting its holder a military horse paid for by the state, along with the cost of its fodder for its whole life. The money for the horse was called "aes equestre", whilst the annual money