The study of the Rudapithecus crania reveals a de-coupling in hominid brain evolution. Cranial shape overall is African ape-like, the shape of the endocast is more primitive, and the sulcal pattern is generally hominid-like. The Rudapithecus endocasts provide evidence of the primitive condition of the brain in hominine evolution.
Assance et al. (Sun,) studied this question.