American Cheetah

AMERICAN CHEETAH
Scientific name: Miracinonyx trumani
Scientific classification:
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Felidae
When did it become extinct? The American cheetah is thought to have become extinct around 10,000 years ago.
Where did it live? This cat was native to North America.

extinct animals

The pronghorn antelope ( Antilocapra americana ) of North America is one of the fastest land animals on the planet, able to reach speeds of 100 km per hour for short bursts and 40 to 50 km per hour over long distances. Why does it need such a turn of speed? There are no American predators that can sprint anywhere near fast enough to catch an adult
pronghorn in a straight pursuit—well, there aren’t any today. Some scientists believe that the pronghorns evolved to run so quickly as a way of evading an American cat that evolved along the same lines as the African cheetah ( Acinonyx jubatus )—a slender feline built for speed. This was the American cheetah. The idea of a cheetahlike animal sprinting after pronghorns on the American Great Plains seems far-fetched, but prehistoric America was a very diff erent place from the place we know today.
Remains of this sprinting cat are exceedingly rare, which is what you would expect for a light, slender-boned animal that was probably uncommon. With that said, the discoveries we have allow us to reconstruct what this animal may have looked like and how it may have lived. The bones of this animal were found in Natural Trap Cave, Wyoming—a big hole
in the ground, where lots of prehistoric beasts met an unfortunate end—and Crypt Cave, Nevada. Up until the late 1970s, these bones were considered to be the remains of puma like cats, but when some experts had a really close look at the bones, it was obvious that the cat in question was no puma. Like the modern-day cheetah, its skull had a very short muzzle, which gave it a rounded appearance, and the nasal cavities were very large. In the cheetah, these enlarged nasal cavities allow the animal to suck in big lungfuls of air during and after high-speed chases. The similarities also extend to the dentition as the modern cheetah has an interesting arrangement of cheek teeth, allowing the upper and lower sets to act like a single set of meat shears. As the skull of the extinct American cat had the same characteristics, we can assume that it had the same predatory lifestyle as the cheetah—a hunting strategy dependent on high-speed pursuit of fast moving prey. Th anks to its big cheek shears, the African cheetah is one of the only cats that routinely eats bones, normally parts of ribs and vertebrae, and as the American cheetah’s teeth are so similar, it may have done the same.
It is true to say that the skeletons of the long-dead American cheetah and the African cheetah are very similar, but there are some key diff erences, and one of the most obvious is size. On average, a fully grown African cheetah is around 67 kg. Using the skeleton of the American cheetah as a guide, this extinct animal may have been more like 80 kg. Also, the claws of the modern cheetah are completely non retractable, a feature that gives the cat a good grip when it is pursuing prey (think of a human athlete wearing running spikes).

The claws of the American cheetah could be fully retracted, which has led to the suggestion that this cat may not have been as specialized as the fast-running African feline we know today. The forelimbs of the American cheetah are also sturdier than today’s cheetah, and they were sheathed in bigger muscles. Greater strength in the upper body, an interesting arrangement of the bones in the lower hind limbs, and retractile claws suggest that this animal may have been able to climb trees, something that today’s cheetah defi nitely cannot do. However, these diff erences aside, so much of the American cheetah’s skeleton is similar to the modern cheetah that it is very reasonable to assume these animals had very similar lifestyles.
How was the American cheetah related to the African cheetah? You would assume that being so similar, the American cheetah and the living African cheetah would be very closely related, and it has been argued that the American cheetah could have crossed the Bering land bridge into Asia, eventually arriving in Africa and spawning the cheetah we know today. However, nature is never that simple, and it is much more likely that these similarities arose due the process of convergent evolution—the phenomenon by which two unrelated species end up resembling one another because they adapt to similar circumstances.
Fortunately for the pronghorn antelope, the American cheetah died out around 10,000 years ago. Its extinction coincides with the disappearance of many North American mammals, but what factors ultimately led to the demise of this feline are more of a mystery. Climate change was obviously a factor, and the loss of some of its prey species may also
have been important. It is possible that such a specialist cat really felt the squeeze of climate change and the eff ect it had on its environment. The puma, a generalist predator, is still with us today, but the American cheetah was more of a one-trick cat that survived by using speed to catch a small selection of prey animals. In today’s big cats, we can see the price of extreme specialization, as the living cheetah is becoming increasingly endangered as its habitat is
squeezed ever harder by human activities.
• The name “American cheetah” is often used to describe two extinct North American cats, the other being M.  inexpectatus , which was a larger, and even more ancient species. In terms of appearance, this cat was halfway between the living cheetah and the living puma, and it may have been a more generalist predator than M. trumani.
• The cheetah and its prey (usually, gazelles, Gazella sp.) are often used to exemplify the concept of evolutionary arms races . In this case, the cheetah and the gazelle are locked in a struggle—if the cheetah evolves to run slightly faster, it will be able to catch more prey, weeding out the slower individuals from the population of gazelles; the surviving, faster gazelles pass on their fl eet-footedness to their off spring, and eventually, these quicker individuals will predominate. So this process goes, with evolution continuously honing each species so that neither has the advantage for
long.

• Natural Trap Cave in Wyoming is a bell-shaped sinkhole at an altitude of around 1,500 m. Th rough a 4-m-wide hole at the surface, an unlucky animal would fall around 25 m to the cave floor. There is no route out of the cave once at the bottom, so if the unfortunate beast was not killed by the fall, it would have slowly starved. Over the millennia, lots of prehistoric and modern animals have stumbled into this hole, and it is now a site of extreme paleontological importance.

Further Reading: Adams, D. B. “The Cheetah: Native American.” Science 205 (1979): 1155–58.

Advertisements

One thought on “American Cheetah

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s