Canis lupus hominis

The answer to the question is Homotherium serum. It is also known as the “scimitar cat.”

Source.

It is not a Smilodon or an American lion (Panthera leo atrox).

The genera Smilodon and Homotherium are relatively closely related. They both are in the subfamily Machairodontinae.

Machairodonts were in the cat family. They were not pantherine cats, like tigers, lions, leopards, and jaguars. They were in their own subfamily.

It is incorrect to call members of the Smilodon genus “saber-toothed tigers,” even though that’s what the Flintstones called them.

You can tell that this particular cat is a Homotherium because of its prey. Dall sheep have always occurred in the northwestern part of the continent. Smilodon fatalis, a contemporary of both ancient Dall sheep and Homotherium serum, existed only the southern part of the North American continent. The two animals likely had an overlapping range, but they may or may not have been direct competitors. It is believed that the Homotheriums serum was a creature of higher latitudes and higher altitudes than Smilodon fatalis, kind of like how the modern bobcat inhabits warmer areas than the Canada lynx.

One of the hallmarks of Homotherium is that the forelegs are longer than the hind legs. It was also at least partially plantigrade, which is unlike any modern cat species.

The other identifying feature of this cat is the deepened lower jaw. Lions, including cave and American lions, and tigers don’t have this feature.

The Homotherium cats lasted until about 10,000 years ago in North America.

Traditionally, the cats are believed to have lasted in Eurasia until 30,000 years ago, but there is some evidence that they lasted in Britain until as recently as 11,000 to 13,000 years ago. (There is also a remarkable figurine in that post! It may give us some idea about what these cats looked like!)

Here’s a more modern depiction of the species– minus the deepened lower jaw and the partially plantigrade feet:

So it’s not an American lion or a Smilodon.

It’s a scimitar cat.