Doris Piserchia’s 1976 A Billion Days of Earth is a standalone SF novel.
A billion days from now — which translates to some three million years — humanity has become a race of gods. Evolution (as well as genetic tinkering) has resulted in a world filled with super-capable humans and new non-human species … many of which are as smart as humans of our time, if not as smart as the godlike humans. These new species can also be as foolish as humans of our time (which, as we know to our sorrow, can be foolish indeed).
Into this world comes a new predator.