Equine Lec 1

result of genetic adaptation to environmental changes

Evolution

Scientific classification of horses

Animalia, Chordata, Mammalia, Perissodactyla, Equidae, Equus, E. ferus

The very first horse evolved on the?

North American grasslands

Horrse evolution dates back to _______, about ______ years ago

Eocene epoch, 60 million

• earliest ancestor of the horse, about 60 mya (Eocene)

• about 2 feet in height, the size of a cat or a dog

• arched back and snout-like noses

• body is spotted

Eohippus (dawn horse) or Hyracotherium

• about 40 mya, Oligocene

• about 24 inches at the shoulder

• back less arched, face, snout and neck somewhat longer

• spot gradually reduced

Mesohippus (middle horse)

• effective grazer and runner

• middle of Miocene epoch about 30 mya

• wider molar for crunching hard grasses

• hindlegs relatively short

Merychippus (ruminant or cud-chewing horse)

• during the Pliocene (Ice Age) period, 10 mya

• grew bigger that their ancestors and looked like the modern horse

• teeth strongly curved but became better fitted for eating grass

Pliohippus

• Horse we know today

• Dos not have a dished face

• 30,0000 years ago they were used for farming and migration

Equus