Ever wonder about the heritage of your majestically regal horse friend? Would you believe he shares his ancestry with -- rhinoceroses? True story! Over fifty million years ago, horses had several odd-numbered hoofed toes and looked more like tiny rhinos or small deer than anything remotely resembling their modern counterparts. With four toes on its front feet and three toes on its hind feet, this diminutive creature was well suited to spending most of its time in dense woodlands, honing its survival skills.
Successfully enduring a harsh physical environment enabled these little mammals to gradually develop into what’s known as the “intermediate” or “marginal” horse, a slightly heavier several-hundred-pound version sporting better teeth for grinding. This creature’s evolution included enlarged middle toes, as well as a more adventurous spirit; he spent more time seeking food in meadows than in forests, eventually gravitating to the lush, open North American plains where food was plentiful.
By about twenty million years ago, (during the Miocene era), these intermediate ponies had adapted well to the changing environs of Earth, including its open plains. The animals gradually developed prominent middle toes and long legs, better enabling them to follow their compulsion to graze and to quickly run from predators that could easily spot the horses in the wide, open spaces. Bigger, more athletic horse-like animals made their appearance, including one called “Parahippus,” or “almost horse.” These mammals displayed long legs, strong teeth and even more enlarged middle toes. They were evolving to reach weights of around 1,000 pounds, nearing the size of our modern horses. In addition, they possessed a fast gait and the ability to run like the wind.
“Hippidion” then appeared, considered the most successfully evolved horse, as evidenced by its migration from North America to Africa and Eurasia. The significant difference between Hippidion and our modern horses was the two barely-noticeable vestigial toes surrounding its single-toed hooves.
Hippidion was such an auspicious traveler that he’s thought to be one of the few ancient horses to have made his home in South America. This animal had prominent nasal bones to assist with his highly-developed sense of smell. He may be the prehistoric pony most closely related to modern equines.
The genus “Equus” is category to modern horses, zebras and donkeys, all of which progressed about 4 million years ago (during the Pliocene era). A note of interest is that the last Ice Age witnessed the extinction of both North and South American horses. It was only on Eurasia’s plains that they continued to flourish.
To our everlasting gratitude, mammals in the genus Equus, including our magnificent modern mounts, were reintroduced to the Americas by Europeans during their colonizing expeditions of the 15th and 16th centuries A.D.
And, equally significant and appreciated is the incredible beauty possessed by the horses of today. And to think it all started with a little “rhino-like” critter.
Photo: Eurohippus, an extinct genus of equid ungulate (placental mammals having hooves with an odd number of toes on each foot).