This one I offer at times now and again as it is directly relevant to myself but it is really a telling and fascinating function of evolution based upon recurrent adaptations over many generations that were highly favorable.
Among the machairodonts, thus the many, many sabertooth cats, two primary adaptations arose to solve the same sorts of problems; "dirk tooth" cats, the kind we all know and the likes of which sabertooths are most famous for, and the much less spoken about "scimitar tooth" cats. The latter here is extremely unique and in part actually some of the reason we see so few canids in the Americas (in particular) and even Europe, because scimitar tooth cats were much more generalized with their less pronounced, less flattened exaggerated canines, but also had longer limbs and a number of species were cursorial hunters - all traits that put them in direct competition with species such the various wolf species. This is all on top of "conical tooth", thus Pantherine, large cats that are still extant today. But once upon a time, it was so common a case there were many more species of cats, that there was virtual out-competition of every other predatory land mammal on the entire planet and had been increasingly that way - just thanks to tooth shape in large part - over tens of millions of years.
Things have only changed in the past fifteen or so thousand years, predominantly due to natural changes in planetary temperature with the end of the last ice age, then the following rapid expansion of humans with the Agricultural Revolution.