Notes:

Y'know, I've thought about this sort of thing a lot, and I've always had a theory about anthros that I find reasonably sound:
Humans (to grossly oversimplify) evolved from monkeys.
We all know that. Yet plenty of species of primates still exist, because it's a matter of common ancestry and branching evolution, not direct descent like shown in the classic 'March of Progress' diagram.
By that logic, it stands to reason that, in some alternate universe, other species of animals' evolutionary paths could branch in similar ways.
Anthro cats would share a common ancestor with regular cats, but both would still exist, along with various other species that evolved to become bipedal and intelligent (foxes, bears, alligators, mice, etc.)
I realize there are a lot of complex biological and evolutionary issues with that theory, and it's not nearly as simple as I'm putting it, but I'm not going to devote years of my life to proving the validity of furries.
It's fantasy. A 'good enough' theory is enough for my suspension of disbelief.