The pronghorn is one of North America’s most unique animals. While many people think it’s a type of antelope, it isn’t actually closely related to them. In fact, its closest living relatives are the giraffe and okapi.
The pronghorn’s similarity to the antelope is a commonly cited example of parallel evolution. Both species fill the same ecological niche, so despite living on different sides of the Atlantic Ocean, they have both evolved similar body plans.
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2 Fast 2 Furious
What sets the pronghorn apart in North America is its blinding speed; it can reach up to 55 mph in a sprint. No other North American species can come close to matching the pronghorn in a footrace. In fact, you could say that the pronghorn is way faster than it needs to be.
Though not quite as fast as a cheetah, the pronghorn can sustain its top speed for far longer. But there aren’t any cheetahs in North America. Pronghorns could be slower and still outrun any predators they come across. So why did they evolve to run so fast?
Cheetahs In North America
The answer is simple: The predators they evolved to outrun don’t exist anymore. During the Ice Age, North America was home to a wide variety of now-extinct megafauna. We’re all familiar with animals like the woolly mammoth and the saber-toothed cat Smilodon, but a lesser-known Ice Age predator was the American cheetah.
The pronghorn’s unbelievable speed and endurance would have been their only hope at outrunning the American cheetah. Luckily for them, their most dangerous predator went extinct with most of the other Pleistocene megafauna, leaving the pronghorn as the undisputed North American land speed champion.