Involves a group of upright 'evolved'/human like monkeys who seem to... 1. Erroneously think they're human as humans have disappeared from Earth 2. Have the ability to share souls or memories or something very intimate through their tails alone.
Story is set in distant future where earth is shared by 5 sentient races or so. Wasp like baddies who are trying to take over everything, dinosaur like overlords who hibernate for millions of years at a time and re-emerged while humans were still kicking about (I distinctly remember them having suicide machines). There were also a sentient species of plant, and after that I'm much more fuzzy, maybe some kind of robot or a fish....I don't know.