There's also a hypothesis that the multiple superimposed legs drawn on certain cave paintings is a proto-animation. For example the boar from Altamira whose legs are in various poses of its stride.
I always think of that as a form of cubism, but I suppose I should say that cubism is a call-back to those early efforts.
I associate cubism with multiple viewing angles of a single thing, as opposed to multiple things viewed from a single angle. But definitely agreed that cubism was a rediscovery of a lot of earlier artistic traditions of interpretation that fell out of favor during the ascendance of "realism."