CT scanning and 3D digital reconstruction of a 20 million year New World Monkey suggest that the conventional wisdom--that evolving brain size relative to body mass led to why we're so smart--may not be as straightforward as we once imagined! (Of course, nothing in this line of research is!). Reported here: https://www.asiatimes.com/2019/08/article/ancient-monkey-skull-reveals-brains-secrets/; you can find the published research paper here: https://advances.sciencemag.org/content/5/8/eaav7913/tab-pdf.