Ever wonder why Pronghorn run so fast? Well Miracinonyx was the reason why this antelope evolved such amazing speed.

Also known as the American Cheetah, Miracinonyx is an extinct species of big cat that roamed the continent of North America during the late Pliocene 2.6 million years ago to the late Pleistocene 11,000 years ago.

There were actually two species of Miracinonyx that existed in North America at the time, Inexpectatus and Trumani. There may also have been a third species known as Studeri, but it isn't clear if it is a different species or a juvenile Trumani.

Trumani was built more like the modern-day African Cheetah while Inexpectatus had a design that was closer to the Mountain Lion, but it also showed a lot of similarities with the Cheetah.

Another difference between the two species is that Inexpectatus possessed retractable claws while Trumani did not.

Although known as the American Cheetah, Miracinonyx was actually a closer relative to the Mountain Lions of today.

Finally we can't talk about the American Cheetah without mentioning its speed. Miracinonyx is believed to have been able to run at a top speed of 60 miles per hour.

To give you an example of how fast Miracinonyx was here's a video of a Pronghorn running.

As you saw in the video, the Pronghorn had no problem keeping up with the car that was going at 40 miles per hour. Therefore, a Miracinonyx that is moving at its top speed would have been surpassing the car!

Trumani

Diet: Small to medium sized animals, but primarily Pronghorns.

Casualties: One Pronghorn.

Anomaly incident: An anomaly opened up in the Grand Teton National Park located in Wyoming and a large Miracinonyx crossed through it.

The American Cheetah ran off into the national park as it began its search for something to eat.

Meanwhile at the ARC facility the anomaly's signature appeared on the monitors and soon an ACR team was headed off towards the anomaly's location.

Back in Grand Teton National Park the Miracinonyx found a herd of Pronghorns that was grazing near Jenny Lake.

Upon seeing its favorite prey, the Miracinonyx began to creep up on the unsuspecting antelopes. When it got to approximately 16 feet away from the Pronghorns, the American Cheetah leaped out of its hiding spot.

The Pronghorns began to run away as fast as they could while their ancient enemy relentlessly pursued them.

As the chase continued, the Miracinonyx separated one of the slower antelopes from the herd and pursued it into an open field.

Eventually the American Cheetah overtook the Pronghorn and with one last push it tackled its prey to the ground.

Before the Pronghorn could get back up the American Cheetah bit down on its throat and began suffocating the antelope until it stopped moving.

Meanwhile the ARC team arrived at Grand Teton National Park and began to search for the anomaly and any possible creatures that might have crossed over to their time period.

The ARC team soon located the anomaly as well as found footprints that led away from the anomaly. The ARC team split up into two groups with half of the team staying at the anomaly while the other half followed the track.

A few hours later the ARC team found the Miracinonyx sleeping not too far away from its kill.

As they got ready to tranquilize the American Cheetah for transport their portable radios went off and woke up the sleeping feline.

Before the ARC team was able to take aim and shoot it the Miracinonyx had already run off into the forest. With no time to waste the ARC team began pursuing it through the forest.

Later after losing sight of the big cat the ARC team began to hatch a plan on how to catch the Miracinonyx.

But as they were discussing the plan some of the team members noticed the American Cheetah creeping up on them.

Before they could do anything else the Miracinonyx leaped on top of zoologist (*******'s) back and tried to get to his throat. But luckily for (*******) his backpack got in the American Cheetah's way making its attack ineffective.

With the Miracinonyx distracted the rest of the ARC team unleashed a barrage of tranquilizer darts into the animal's body and in a matter of seconds the American Cheetah was unconscious.

The ARC team brought the sleeping American Cheetah back to the anomaly and pushed it back through just as it closed sealing the Miracinonyx in its own time period.