The name T-Rex means “king of the tyrant lizards” and it appears to be just that T. rex it was. A ruthless and fearsome predator, it ruled the world during the late Cretaceous period, about 90 million years ago. With teeth the size of a banana, a crushing bite and a sense of smell as sharp as a cat’s, this outrageous one theropod was a ferocious predator. But how clever he was T. rex? What do we know and what can we know about the brain of the most ferocious predator the world has ever seen?
Clues from T. Rex Skull
According to Ashley Morhardt, a paleoneurologist at the University of Washington School of Medicine, some things are evident from the fossil record that may give us some clues about dinosaur intelligence. For example, we can observe and measure the space of the cavity where the brain was once located.
T. Rex brain
If the skull has been fractured due to damage, researchers can physically examine the inside of the brain. The skull may also be placed in a CT scan (CAT) scan that provides a detailed image of the interior of the brain cavity. In some cases, scientists may also make an endocast, or a 3D representation of the brain cavity made using a method similar to a jelly mold. Endocasts are particularly useful because they show the size of the brain cavity as well as the anatomical details of the brain.
“We can get an idea of how much brain tissue was dedicated to different areas of the brain by being able to analyze the anatomy of the endocast,” says Morhardt.
Regarding T. rex, we know that he had extremely large olfactory bulbs and, as a result, a great sense of smell. We also know from the size of the eye sockets that he has excellent eyesight.
Read more: New species of dinosaur could explain the evolution of Tyrannosaurus rex
Size of a T. Rex brain
A July 2022 study published in Journal of Comparative Neurology we went a step further using the information we have about the neuron density and brain size of animals living today and tried to apply this knowledge to T. rex.
Smart as a baboon?
The study, authored by Susanna Herculano-Housel, even estimates this T. rex was almost as smart as a baboon, which means they were smarter than we thought. But Morhardt says there are too many caveats in the study to go that far. “I personally don’t find this claim realistic because brain size only tells us a small part of the story,” she says.
T. Rex Brain size and neurons
Brain size is important, as is neuron density. Yet, we also need to be able to map the neural connectivity of the brain to assess its performance and look at how supporting cells in the brain influence brain activity. So there’s a lot we don’t know and it’s better not to jump to conclusions. “We have to be careful to stay within the bounds of the data,” says Morhardt.
Evaluation T. Rex Intelligence
Matthew Carrano, curator at the Smithsonian’s National Museum of Natural History, agrees that there’s a lot we just don’t know. He says we haven’t even mastered measuring the intelligence of living human beings. “To go back in time and measure the intelligence of an ancient animal, it’s really hard to even approach this question in any precise way,” he says.
Tree of Life
He argues that we have secondary ideas that can provide a window into T. rex intelligence, but for now it would be a challenge to go beyond that. We can get a sense of dinosaur intelligence based on where they fit on the tree of life, Carano says.
“We know we have living dinosaurs in birds and close dinosaur cousins in crocodiles, so we can use what we know about these living animals to bracket the possibilities of dinosaur intelligence,” he says.
Bird Brained?
Yet there is a range of intelligence in birds. Some are quite smart, like parrots and ravens, but others are not so sophisticated. Also, birds have changed a lot in the last 66 million years. And then there are crocodiles, which in some research, are highly intelligent, work in teams to hunt their prey, and show advanced parental care. And they haven’t changed much, but we’re still not sure how close they were to the dinosaurs in terms of intelligence.
Read more: Is T. Rex three different species?
After all, there’s a lot we don’t know about dinosaurs or T. rex intelligence and it seems difficult without the brain to know. But the more specimens we find showing behavior, culture and sophistication, the more we can pull back the curtain on the brains of this fantastic beast. Until then, we’ll have to throw our hats at this idea T. rex was as smart as needed to rule his prehistoric world.