2024-04-27 13:55:33
However, a new paper refutes this conclusion.
“These were very bold claims that required a second look,” says Cristian Gutierrez, a neuroscientist at the University of Alberta and co-author of an article in “The Anatomical Record” that casts doubt on the theory surrounding the intelligence of Tyrannosaurus Rex.
Suzana Herculano-Houzel of Vanderbilt University, Nashville, published research in 2023 that took data on the number of neurons in the brains of the evolutionary descendants of some dinosaurs, such as modern birds, reptiles and turtles, and applied them to fossilized brain cases of ancient lizards.
Writing in the “Journal of Comparative Neurology”, she concluded that Tyrannosaurus rex had between two and three billion neurons, equivalent to those in the brains of intelligent primates, such as baboons.
“(This) would make these animals not only giants, but also long-lived animals with flexible cognition and therefore even more amazing predators than previously thought,” she said.
But no, replies Mr. Gutierrez.
He writes that Ms. Herculano significantly overestimated the size of the actual brain inside the skulls of tyrannosaurus rexes, which were much more closely related to modern crocodiles than to birds. Crocodile braincases contain a significant amount of non-cerebral fluid and tissue, of which only 30% is devoted to gray matter.
Additionally, bird brains are much denser with neurons than reptilian brains, further contradicting Herculano’s comparison.
Then there is body size. Although the brain of a tyrannosaurus rex contained as many neurons as that of a baboon or a magpie, that brain had many more bodies to work with.
“Obviously, larger animals need more neurons,” says Gutierrez.
“A T. rex, for example, had two billion neurons, about the same as a baboon. But the t. rex weighed seven tons and the baboon weighs 40 kilograms. It’s not the same, right?”, he explains.
In addition, more neurons do not necessarily mean more intelligence, Gutierrez points out.
Giraffes have approximately two billion neurons, but are not known to use tools or transmit culture. Magpies, on the other hand, have only about 400 million neurons, but play games and hold “funerals” for their dead.
Herculano did not immediately respond to a request for comment on Gutierrez’s article, available since April 3.
Gutierrez says that his previous research showed that there are connections between behavior, brain size and the size of different parts of the brain.
“They’re not always simple correlations, but they are correlations. “It’s not completely crazy to look at the shape of the T. rex brain,” he says.
Dinosaurs more closely related to birds, such as Archeopteryx from the Jurassic period, had larger brains and could display more complex, bird-like behavior, says Gutierrez.
Fossils provide some clues about how the dinosaurs lived. For example, they can show dinosaurs that took care of their young and lived in groups.
“But it will always be limited,” argued Mr. Gutierrez. It’s the only thing that won’t fossilize: behavior.”
An intelligent tyrannosaurus rex is highly unlikely, Gutierrez maintains. These monsters probably had an intelligence closer to that of a crocodile than a primate, so keep calm.
If the idea of a seven ton crocodile lets you sleep easy.
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