Hadrocodium
neurophilosophy | May 19, 2011Skull of Hadrocodium wui. (Image courtesy of Mark Klinger and Zhe-Xi Luo, Carnegie Museum of Natural History)
THE question of how mammals evolved their exceptionally large brains has intrigued researchers for years, and although many ideas have been put forward, none has provided a clear answer. Now a team of palaeontologists suggests that the mammalian brain evolved in three distinct stages, the first of which was driven by an improvement in the sense of smell. Their evidence, published in tomorrow's issue of Science, comes from two fossilized skulls, each measuring little more than 1cm in…