Evolutionary Stages of the Horse

The species of horse that we know today went through millions of years of evolution to become the graceful athletes they are today. Many horse-like animals branched from the same evolutionary tree over time and evolved along various unrelated routes. They vary greatly, differing mainly in the number of toes, adaptations, and diet. Now one genus – Equus - is the only surviving branch. Equus Caballus is today's true horse. There are 6 main Evolutionary Stages of the horse - let's delve into them. Fun Fact: The horse is one of the few animals that we have a nearly complete evolutionary record for. All the main stages of the evolution of the horse have been preserved in fossil form and documented!

Evolutionary Timeline

1. The first equid was Hyracotherium, a small forest animal of the early Eocene, which lived 55 million years ago. It looked nothing like a horse – it actually resembled a dog with an arched back, short neck, short snout, short legs, and long tail. This famous little equid is also known as Eohippus.
2. The next evolution, Mesohippus, appeared in the Oligocene epoch, about 45 million years ago. This animal was a slightly larger version of Eohippus with one less toe, but still no hooves. At this time, the species resembled more of a small horse than a dog. The back was less arched and the legs and neck grew longer.
3. 35 million years ago, Miohippus was the current genus. The typical miohippus was distinctly larger and had a slightly larger skull than a typical Mesohippus. At this time, the facial fossa, or indent above the eye, was deeper and more expanded.
4. About 17 million years ago, Merychippus joined the equine line at about 10 hands tall or 40” tall, the largest yet. The muzzle became elongated, the jaw deeper, and the eyes moved farther back to accommodate the large teeth roots. They adapted to the grasses of the plains, marking the beginning of today’s grazing horse. This species was distinctly recognizable as a horse with a very “horsey” head.
5. Next, nearly 5 million years ago arose Pliohippus, the first one-toed, hooved horse. In order to outrun predators, the Pliohippus needed speed, so the hoof evolved from the continual over-development of the middle toe during this time. The teeth and limb forms were very close to the modern-day horse.
6. Present Day, Equus is the genus of all modern equines. The first Equus was about 13.2 hands tall, or pony size with a classic “horsey” body – a rigid spine, long neck, legs and nose, and fused leg bones with no rotation. Equus was (and still is) one toed, with side ligaments that prevent twisting of the hoof, making their legs into sturdy mobiles for riding and working use.

Throughout history, the horse has occupied a powerful place in the emotional, spiritual, and physical daily lives of human beings. It’s incredible to see how far horses have evolved to become such a large role in society; from athletes, to service animals, to police horses, and even our best friends. With great power, comes great responsibility, and it’s our responsibility to make sure they are well taken care of our horses. Tip: Benefab by Sore No-More has just the product to pamper and give your horse the pain management and prevention they need for all the work they do for you. The Rejuvenate SmartScrim features over 80 magnets sewn over key acupuncture points for stimulation of specific beneficial points, ultimately helping to relieve and prevent pain and stiffness. Best of all, it’s clinically proven to reduce back soreness in moderate to high exercise horses! Click here to learn more.