These Mammals Had a Good Run, So What Happened?

[JDaileyGreatLakes]

There are certain groups of mammals who had a very long run until very recent in geological history.

Paleomerycidae (55.8-4.9 MA)

Hyaenodonta

Creodonta (63.3-11.1 MA)

Entelodontidae (37.2-16.3 MA)

Merycoidodontoidea (35-5 MA)

Hyracodontidae (55.8-20 MA)

Leptictidia (70-33 MA)

Amphicyonidae (46.2-1.8 MA)

If these numbers are any indication, it proves that these prehistoric mammals had a resounding success. So what happened? What drove them into extinction?

[Prudentia]

Most of the above likely became extinct due a number of reasons, but one of them being competition from more competitive groups.

[JDaileyGreatLakes]

Most of the above likely became extinct due a number of reasons, but one of them being competition from more competitive groups.

How do you mean, "more" competitive?

[Prudentia]

Most of the above likely became extinct due a number of reasons, but one of them being competition from more competitive groups.

How do you mean, "more" competitive?

I mean better adapted to do exactly what the other creatures did. Members of Carnivora drove the creodonts to extinction since they were better suited to hunting than the Creodonts. In other words, Carnivora did exactly what Creodonta did, except they [Carnivora] did it better.