Are Horses Really Flipping Us Off?

By: Theresa Green

The simple answer is yes! The horse of about 55 million years ago looked more like a fox than today's horses. They were small creatures that had a foot like a dog. They had four toes, and I dewclaw. Through evolution, the horse changed a lot. Slowly, over time, the horse started to get larger. As it got taller, to be able to reach more vegetation, their toes started recessing. The first toe to go was the dewclaw and pinky finger/toe. Next the pointer finger/toe and ring finger/toe start to move up the leg. Meaning that at one point the horse had one larger toe, the middle finger/toe, and the ring finger/toe and pointer finger/toe no longer touched the ground, but still had a hoof on it. As the animal got taller, and started looking more and more like today's modern horse, the extra toes disappeared. This left the horse with one large toe on each foot. This toe was the middle finger/toe. We can still find evidence of these old, recessed toes on today's horse. 

If we look at the skeleton of a horse's front leg, what we call their knee is really their wrist. Now let's play a game of, this bone is connected to that bone. If we go down the leg, below the knee is cannon bone, which is the long bone that makes up the lower leg. On either side of the cannon bone are splint bones. They are partly fused to the cannon bone. If you feel your horse's lower leg, you can feel these bones on either side of the cannon bone. The splint bones are what is remaining of the ring finger/toe and the pointer finger/toe. Do you know what chestnuts are? Chestnuts are the weird spot on the inside of your horse's leg, just above the knee and hock. That is what is left of the thumb/big toe. And the hidden pinky finger is the ergot. You can find the ergot at the bottom of your horse's fetlocks, on the lower, back side.

Why did horses evolve this way? Our best guess on the matter was that it made it harder for predators to take them down. Switching from a 5 toed, pawed foot to a hooved singe toe meant that they could run a lot faster. But, if they were going to need to run faster, they were going to need a larger heart and set of lungs. So they got bigger. Plus, it was harder for predators to take down a larger animal than a smaller one. It was all about survival. There are a handful of identifiable pauses along the horses evolutionary path, but experts are now starting to think that we may have had many different evolutionary horses around at the same time. Which could explain how we ended up with the differences between horses, donkeys and zebras, all of which are in the equine family. 


Photo Credit
Evolution Photo
https://www.missysbucket.com.au/blogs/horse-health/equine-evolution-teeth-and-digestion

Comparing Horse Front Leg to Human Hand
https://www.americanfarriers.com/articles/11385-equine-reciprocating-systems-interosseous-muscles-to-the-suspensory-apparatus?v=preview

Comparing Horse Back Leg to Human Foot
https://www.americanfarriers.com/articles/12941-hock-provides-the-horse-thrust-under-immense-strain?v=preview