Modern reptiles have relatively small brains, with half of the cranial cavity’s space being taken up by sinuses that serve as a blood drainage system. Curiously, the tissue in this Iguanodon brain appears to have been pressing up right against the skeletal structure, hinting that the brains of dinosaurs could have been far larger than many have previously assumed.
“It seems that the brain in this dinosaur was therefore more similar to that of modern birds, in that it filled a greater proportion of the braincase,” Liu added.
However, it’s possible that the dramatic death of the dinosaur may have dislodged the brain somewhat, causing it to have been preserved against the skull when it reality it may have been positioned further away. Without seeing the lobes of the brain itself, the team cannot be certain about the true size of its brain.
The lead author of the study, Professor Martin Brasier of the University of Oxford, died in a car crash in 2014 while in the middle of researching this incredible fossil, and this special publication is dedicated to his life’s remarkable work.
“Professor Brasier was a very supportive colleague, and it's been a privilege to work towards publishing a paper on this very special object, in a book in his memory,” co-author Dr Russell Garwood, a paleontologist at the University of Manchester, told IFLScience.
He would no doubt have been thrilled to have been part of a discovery that has turned out to be truly revelatory. After all, there’s arguably no better way to determine a dinosaur’s intelligence than by looking at its brain.
The fossilized brain in all its mineralized glory. Jamie Hiscocks