Evrim Yazgin
Cosmos science journalist
How smart were dinosaurs? It’s not clear based on fossil evidence alone. Tyrannosaurus rex, the dinosaur king, is one dinosaur which has been subject to some debate on this question.
A new study, published in the Anatomical Record journal, suggests we might have overestimated T. rex’s smarts.
Last year, a study was published which suggested that dinosaurs like T. rex had a high number of neurons. Based on this, T. rex, the authors of that study claimed, might have been as smart as a primate.
But the new study raises doubt over this conclusion.
International researchers attempted to take a broader look at intelligence inferred not just from the number of neurons, but also taking into account dinosaur brain size and anatomy.
“Determining the intelligence of dinosaurs and other extinct animals is best done using many lines of evidence ranging from gross anatomy to fossil footprints instead of relying on neuron number estimates alone,” says author Hady George from the University of Bristol in the UK.
Minerals filling the brain cavity of ancient animals leave endocasts. These can be scanned to build a picture of what extinct creatures’ brains were like. Based on this, we know T. rex, for example, had large olfactory regions pointing to a very sharp sense of smell.
The brain size of T. rex, it turns out, has been overestimated – especially in the front part of the brain. Therefore, the neuron number has also been overestimated.
“The possibility that T. rex might have been as intelligent as a baboon is fascinating and terrifying, with the potential to reinvent our view of the past,” says Darren Naish from the University of Southampton, also in the UK. “But our study shows how all the data we have is against this idea. They were more like smart giant crocodiles, and that’s just as fascinating.”
