Sifrhippus sandrae Mesohippus bairdi Anchitherium clarencei Parahippus leonensis Archaeohippus Protohippus gidleyi blackbergi Calippus elachistus Cormohipparion plicatile Species: Mesohippus Species: Sifrhippus bairdi sandrae Subfamily: Anchitheriinae Subfamily: NA Tribe: NA Tribe: NA Epoch: Eocene to Oligocene Epoch: Eocene First Appearance: 33.9 Ma First Appearance: 55.8 Ma Last Appearance: 33.3 Ma Last Appearance: 50.3 Ma Size: ~40 kg (90 lbs) Size: ~5 kg (~ 11 lbs) Number of Toes: 3 Number of Toes: 4 Molar Crown Height: brachyodont Molar Crown Height: brachyodont Species: Parahippus Species: Anchitherium leonensis clarencei Subfamily: Proposed ancestor Subfamily: Anchitheriinae to the subfamily Equinae Tribe: NA Tribe: NA Epoch: Miocene Miocene Epoch: First Appearance: 18.0 Ma 20.4 Ma First Appearance: Last Appearance: 13.6 Ma 16.0 Ma Last Appearance: Size: ~130 kg (~285 lbs) Size: ~75 kg (~165 kg) Number of Toes: 3 Number of Toes: 3 Molar Crown Height: mesodont Molar Crown Height: brachyodont Species: Protohippus Species: Archaeohippus gidleyi blackbergi Subfamily: Equinae Subfamily: Anchitheriinae Tribe: Protohippini Tribe: NA Epoch: Miocene Epoch: Miocene First Appearance: 10.3 Ma First Appearance: 20.4 Ma Last Appearance: 5.3 Ma Last Appearance: 16.0 Ma Size: ~145 kg (~320 lbs) Size: ~45 kg (~100 lbs) Number of Toes: 3 Number of Toes: 3 Molar Crown Height: hypsodont Molar Crown Height: mesodont Species: Cormohipparion Species: Calippus plicatile elachistus Subfamily: Equinae Subfamily: Equinae Tribe: Hipparionini Tribe: Protohippini Epoch: Miocene Epoch: Miocene First Appearance: 10.3 Ma First Appearance: 10.3 Ma Last Appearance: 5.3 Ma Last Appearance: 5.3 Ma Size: ~150 kg (~330 lbs) Size: ~40 kg (~90 lbs) Number of Toes: 3 Number of Toes: 3 Molar Crown Height: hypsodont Molar Crown Height: hypsodont Dinohippus mexicanus Calippus cerasinus Nannippus westoni Cormohipparion emsliei Neohipparion Nannippus aztecus trampasense Equus simplicidens Nannippus peninsulatus Species: Calippus Species: Dinohippus cerasinus mexicanus Subfamily: Equinae Subfamily: Equinae Tribe: Protohippini Tribe: Equini Epoch: Miocene Epoch: Miocene First Appearance: 13.6 Ma First Appearance: 10.3 Ma Last Appearance: 10.3 Ma Last Appearance: 5.3 Ma Size: ~75 kg (~165 lbs) Size: ~245 kg (~540 lbs) Number of Toes: 3 Number of Toes: 1 Molar Crown Height: hypsodont Molar Crown Height: hypsodont Species: Cormohipparion Species: Nannippus emsliei westoni Subfamily: Equinae Subfamily: Equinae Tribe: Hipparionini Tribe: Hipparionini Epoch: Miocene-Pliocene Epoch: Miocene-Pliocene First Appearance: 13.7 Ma First Appearance: 13.6 Ma Last Appearance: 3.6 Ma Last Appearance: 4.9 Ma Size: ~105 kg (~230 lbs) Size: ~65 kg (~145 lbs) Number of Toes: 3 Number of Toes: 3 Molar Crown Height: hypsodont Molar Crown Height: hypsodont Species: Nannippus Species: Neohipparion aztecus trampasense Subfamily: Equinae Subfamily: Equinae Tribe: Hipparionini Tribe: Hipparionini Epoch: Miocene-Pleistocene Epoch: Miocene First Appearance: 13.7 Ma First Appearance: 13.6 Ma Last Appearance: 1.8 Ma Last Appearance: 5.3 Ma Size: ~50 kg (~110 lbs) Size: ~100 kg (~220 lbs) Number of Toes: 3 Number of Toes: 3 Molar Crown Height: hypsodont Molar Crown Height: hypsodont Species: Nannippus Species: Equus peninsulatus simplicidens Subfamily: Equinae Subfamily: Equinae Tribe: Hipparionini Tribe: Equini Epoch: Pliocene-Pleistocene Epoch: Pleistocene First Appearance: 4.9 Ma First Appearance: 1.8 Ma Last Appearance: 1.8 Ma Last Appearance: 0.03 Ma Size: ~80 kg (~175 lbs) Size: ~425 kg (~935 lbs) Number of Toes: 3 Number of Toes: 1 Molar Crown Height: hypsodont Molar Crown Height: hypsodont.