MISSOULA — One of the most fascinating animals to see is a pronghorn antelope but if you blink you might miss them.
Pronghorn antelope are the fastest land mammal in the United States, with a top speed of nearly 60 mph. They can maintain their sprints for much longer than quick carnivores in the U.S.
But why should pronghorn be so much faster than North America’s carnivores? The answer is the antelope are running from the past -- from the ghost of an extinct predator.
During the Pleistocene -- the geological period that began just over 2.5 million years ago -- North America experienced a series of ice ages. During this time prehistoric mammals thrived. Among these mammals the North American cheetah that chased pronghorns over miles of grasslands.
But suddenly, around 11,000 years ago, almost all of these species died. Mammoths, giant sloths and camels all disappeared from the Americas. Only one large plant-eater remained, nearly unchanged since it first began racing through the southwest 30,000 years ago -- the pronghorn.
Most of us don’t think of these antelope-like creatures as prehistoric, but they are living fossils. Pronghorn antelope also have hollow bones much like birds to make them lighter on their feet.