No sērijas “tālu no mana lauciņa, taču interesanti”:

The systematic archaeological study of prehistoric¹ chimpanzee cultures suggests that the “Chimpanzee Stone Age” started at least 4,300 years ago, that nut-cracking behavior in the Taï forest has been transmitted over the course of >200 generations, and that chimpanzee material culture has a long prehistory whose deep roots are only beginning to be uncovered. These findings substantiate the contribution of rainforest archaeology to human evolutionary studies in areas other than the classical savanna-woodlands of East and Southern Africa and add support to fossil discoveries from these other regions indicative of an ancient chimpanzee past.

Iespējams, ka atsevišķās šimpanžu populācijās jau zināmu laiku ir iestājies agrīns paleolīts.