The series seems to imply that organized societal creatures (jellyfish, spiders, like ants today) will be the big survivors and that individually-thinking creatures won't make it, and this desire to limit the effect and adaptability of the individual intelligence I feel is misdirected.
Not a bad show, though I personally disagree that the mammals will be extinct in 100 million years. Even as substantial a hit that killed the dinosaurs wasn't enough to eliminate ALL reptiles or birds, and the little ones certainly got big within 10 million years (crocs and gastornis, e.g.) as did mammals coming up from basic rodent-like things. Certainly, I can accept that some subsets will die out like many already have, but I don't forsee all of them going. If insects and fish will continue to thrive and get tougher, mammals will get tougher just like they always have.