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 (magazine) Carrying the slogan, "The horse owner's resource", "Equus" is meant to be collected by subscribers so they might use articles in past issues as a reference. Each issue has a prominent issue identification number on the cover (e.g., the June 2005 issue is ""Equus" 332"), and an index to articles is published annually. After the June 1998 sale of Shinitzky's Fleet Street Publishing to PRIMEDIA, the magazine was published by the PRIMEDIA Equine Group. From 2007 to 2010, with the completion of the sale of the PRIMEDIA Enthusiast Media group, the publisher was Source Interlink. Since 2010, "Equus" has been