[Oztrich Boy]

So let us follow the nested tree backwards and point to the place where a canine is no longer a canine. What is it then?

An Amphicyonid (Bear-dog)

[Fester Chugabrew]

The bear-dog. Hmmm.

How many fossil remains are there, where are they, and did they retain a heartiness that would allow for varieties ranging from poodle-ish to pit bull-ish as it has been with the canine? IOW, how much of the information on your link has been substantiated by solid evidence and how much of it is conjecture?