Now part of the animal kingdom
What no-one realises is that while they were up there, the monkeys claimed all of outer space for their species. Sadly as the monkeys didn't speak american and very few 'merkins speak Rhesus (and those who do are generally considered insane), the claim was never acknowledged.
I'm sure that in years to come when the monkeys achieve sentience, one of the first actions their lawyers will take is to reaffirm this stake - thus making them the dominant species on the planet
Dominance means being at the top of the gravity well, not the top of the food chain.