Herculano-Houzel is no passive dinosaur observer. The Vanderbilt University neuroscientist is an expert in comparative neuroanatomy, as well as editor-in-chief of The Journal of Comparative Neurology. In 2023 that journal published a paper she authored about the intelligence of theropods, a clade of dinosaurs which includes Allosauruses, Spinosauruses, Giganotosauruses and of course the iconic Tyrannosaurus.
By analyzing data from T. rex remains as well as data from the theropod's closest living bird relatives, including emus and ostriches, Herculano-Houzel concluded that theropod brains had in excess of three billion neurons. That would mean they had more neurons than baboons, with perhaps even enough intelligence to use tools — the T. rex's notoriously tiny arms notwithstanding.
