The Life and Habits of the Father of Cats

Today, all large land-dwelling carnivorous placental mammals belong to a single group named, appropriately enough, the Carnivora. This includes all the cats, dogs, bears, badgers, and many others besides, and it has long been clear that they are a genuine biological group, all more closely related to each other than to anything else. Indeed, the similarities between these animals are sufficient that, even though the current name only dates from 1821, it's essentially identical to the "Ferae" order first described back in the 18th century.

Even if we look at the fossil record, we find that for millions of years, the great majority of such animals were also members of the Carnivora even if, in some cases, their specific family no longer exists. The great majority, but not all. In 1875, American palaeontologist Edward Drinker Cope coined the term "creodont" for a collection of early carnivorous mammals that lacked the key defining features of the carnivorans. His original definition was relatively narrow, but over the next few decades it was expanded until, in 1909, it came to include essentially all of the large land-dwelling carnivorous placentals that weren't carnivorans.