A very cool looking map where you really created a unique atmosphere.
But I think you got caught in between two minds. A planetary map of biome distribution is a rather modern concept and a stone-age planet does not include "rather modern concepts"... Mixing these two influences will yield original stuff, sure, but it's a very fine line to walk on. The more clarity you add the less "primitive" the whole thing will look so be very judicious about it.
And yes. It is indeed a map. Congrats