pliohippus การใช้

• Until recently, " Pliohippus " was believed to be the ancestor of present-day horses because of its many anatomical similarities.
• Also like the modern horse, " Pliohippus " was a grazer that fed of steppe grasses of the North American plains it inhabited.
• The horse preserved here was later found to be a transitional form between the primitive " Pliohippus " and the modern horse genus " Equus ".
• Until recently, because of its many anatomical similarities, " Pliohippus " was believed to be the ancestor of the present-day horse and its relatives in " Equus ".
• However, though " Pliohippus " was clearly a close relative of " Equus ", its skull had deep facial fossae, whereas " Equus " had no fossae at all.
• Based on study of the tooth morphology it is considered unlikely that " Astrohippus " could be an ancestor of modern horses, with the most likely ancestor of " Astrohippus " being " Pliohippus ".
• Fossils of " Pliohippus " have been found at many late Miocene localities in Colorado, the Great Plains ( Nebraska and the Dakotas ) and also Canada . " Pliohippus " has been found beside " Neohipparion ".
• Fossils of " Pliohippus " have been found at many late Miocene localities in Colorado, the Great Plains ( Nebraska and the Dakotas ) and also Canada . " Pliohippus " has been found beside " Neohipparion ".
• Consequently, it is unlikely to be the ancestor of the modern horse; instead, it is likely to be the ancestor of " Astrohippus " . " Pliohippus " stood approximately 1.25 metres, similar to the modern horse.
• This quarry has produced the remains of six other equid genera including " Dinohippus " and " Nannippus " . " A . stockii " was described from the Yepomera locality in Chihuahua, Mexico, by J . F . Lance in 1950 as " Pliohippus stockii ".
• Subsequently, populations of this species entered South America as part of the Great American Interchange shortly after the formation of the Isthmus of Panama, and evolved into the form currently referred to as " Hippidion " ~ 2.5 million years ago . " Hippidion " is thus unrelated to the morphologically similar " Pliohippus ", which presumably became extinct during the Miocene.