Evolution doesn't really deal with where a species splits in two. If anything, species don't exist. Its an abstract grouping of different entities that tend to be able to reproduce together. It only works thanks to in-between links often dying out. If you took a chimp and a human, and made a chain of every ancestor all the way back until you reached a common ancestor, you wouldn't be able to mark when one species becomes another.

We have a few such cases without needing to use time travel. We often refer to them as ring species, but a single ring species would become multiple species if you had one or two areas of the ring wiped out (based on if it is really an unbroken ring or an arc). That the death of one group of animals turns two other groups of animals from being one species into two shows the underlying problem with our classification system.