Surmising even the physical appearance of a dinosaur - or any extinct animal - based on its fossils is a tricky proposition, with so many uncertainties involved. Assessing a dinosaur's intelligence, considering the innumerable factors contributing to that trait, is exponentially more difficult. A study published last year by Vanderbilt University neuroscientist Suzana Herculano-Houzel that evaluated the intelligence of Tyrannosaurus rex, focusing upon estimated brain size and the number of brain neurons, as comparable to that of primates - specifically a baboon - caused a stir in scientific circles.