response: Well, the modern wolf around is not very similar to the ones that were originally domesticated. So implications from this fact means that the dog's direct ancestors are actually extinct.
original_response: dogs and extant grey wolfs are sisters to one another
history: I'm thinking of a dog. What dog? I cannot suggest a dog for you. Do you know much about them though? Like that they're part of the canines genus or that they're the most populous terrestrial carnivore? No, I actually don't know much about what you just asked. Can you tell me bit a more of the dog's history?
knowledge: The dog and the extant gray wolf are sister taxa as modern wolves are not closely related to the wolves that were first domesticated, which implies that the direct ancestor of the dog is extinct.