Using new computer models that can calculate how much ability an ancient hypercarnivore like cave hyena and the saber-toothed cat had to attack on a prey. From the calculations, researchers have come to know that a cave hyena could have killed a 5-year-old mastodon weighing one ton and if present in group then they could easily have taken down a 9-year-old mastodon weighing 2 ton.

Study's lead researcher Blaire Van Valkenburgh, an evolutionary biologist at the University of California, Los Angeles said that the ancient super-predators used to keep massive herbivores like mammoths, mastodons and giant ground sloths in control.

Through this study, the researchers have been unveiling for the first time the role played by the large predators in maintaining ecosystems. Blaire said that in current situation, herbivores like elephants and deer can cause a lot of destruction through overgrazing. This led them wonder what used to happen in the Pleistocene epoch that lasted from around 1 million to 11,000 years ago.

Modern day herbivores, such as elephants and white-tailed deer, can harm environments by stripping them of vegetation through overgrazing or overbrowsing by eating leaves off of trees. This has led many researchers to question why the same thing did not happen during the Pleistocene epoch, when the herbivores that roamed the earth were significantly bigger. The answer lies in the animals that hunted them.

An international team of researchers, including from Duke University, used a computer model to look calculate the size of Pleistocene predators, or hypercarnivores. They then estimated what that size would have meant for the creatures’ ability to hunt.

Nowadays large herbivores such as elephants and white-tailed deer can have devastating effects on the environment by stripping it of vegetation through overgrazing (eating ground plants) or overbrowsing (eating leaves off trees). This brings up the question of what prevented widespread habitat destruction in the Pleistocene epoch, which lasted from about 1 million to 11,000 years ago.

The impact of ancient hypercarnivores on past megaherbivores may have been difficult to appreciate because many extinct hypercarnivores such as saber-toothed cats have no close living counterparts, the researchers noted.

The researchers next estimated the sizes of ancient mammoths and mastodons. To do so, they developed mathematical formulas for the relationship of shoulder height to body mass from previous research on modern captive elephants.

More work is needed to reconstruct Pleistocene ecosystems, "which were clearly hugely different from today," Van Valkenburgh said. "By understanding what we lost, what the productivity of the planet was, we can learn more about the time in which our species evolved and maybe why we've done so well."

It was then found out that ancient hypercarnivores used to keep the number of megaherbivores in check. Study researchers got the idea of the Pleistocene predators through previous research. In order to have the estimation of ancient mammoths and mastodons, the researchers developed mathematical formulas.

Through the models, the researchers concluded that many ancient hypercarnivores used to attack young mastodons and mammoths.