In some instances, however, the feet of such polydactyle horses bear little resemblance to those of the extinct Hipparion or Anchitherium, but look rather as if due to that tendency to reduplication of parts which occurs so frequently as a monstrous condition, especially among domesticated animals, and which, whatever its origin, certainly cannot in many instances, as the cases of entire limbs superadded, or of six digits in man, be attributed to reversion.
From the well-known Hipparion, or Hippotheriu7n, typically from the Lower Pliocene Europe, but also occurring in the corresponding formation in North Africa, Persia, India and China, and represented in the Upper Miocene Loup Fork beds of the United States by species which it has been proposed to separate generically as Neo- lr.:.
D, Hipparion (Pliocene).
Hipparion, we reach small horses which are now generally regarded as a lateral offshoot from the Merychippus type.