An international team of scientists are challenging the high-profile claim that dinosaurs like the Tyrannosaurus Rex, or T. Rex, were highly intelligent — almost monkey-like in some of their habits — in a new study published last month by The Anatomical Record.
The original study claimed that the animals were substantially more intelligent than people believed because they had large brains and an exceptionally high number of neurons. However, the team criticizes how the data was collected and argues that such indicators are unreliable measurements of intelligence anyway.
Graph showing the relationship between brain and body mass in land-living vertebrates. The data shows dinosaurs like T. rex have brain-to-body size ratios similar to those of living reptiles. Credit: Cristian Gutierrez-Ibanez
The team says they found that in the 2023 study, researchers overestimated brain size, especially the forebrain, and in turn, the neuron count as well because they measured brain size using mineral infillings of the brain cavity, dubbed "endocasts." They argue that primarily using endocasts for data collection is "not good practice to predict intelligence in extinct species." Instead, researchers should use "many lines of evidence ranging from gross anatomy to fossil footprints."
In a statement, Dr. Darren Naish, a researcher from England's University of Southampton, called the idea that a T. Rex was as smart as a baboon both "fascinating and terrifying" and has "the potential to reinvent our view of the past." Naish added: "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."
