Tyrannosaurus Rex, a fierce predator that lived in the Cretaceous Period (83.6 to 66 million years ago) has long been thought to be a big, dimwitted brute. However, according to a new study led by Vanderbilt University, T. rex may have been much smarter than scientists previously believed it to be. In fact, this creature’s brain has likely contained enough neurons to potentially allow it to solve complex problems and even form cultures.
“What if the asteroid [which wiped out the dinosaurs 66 million years ago] hadn’t happened? That’s a whole other world that would have been terrifying,” said study author Suzana Herculano-Houzel, a neuroscientist and biologist at Vanderbilt.
Since the soft tissues that make up dinosaurs’ gray matter has not been conserved, Herculano-Houzel looked at T. rex’s bony brain case and compared it to the skeleton of its living relatives: birds. Extrapolating from an examination of the brains of emus and ostriches, she estimated that T. rex’s cerebrum had as many as three billion neurons, which is comparable to a baboon’s brain. In such a case, the dinosaur may have been able to use tools and even pass down acquired knowledge through generations.
Thus, while prior research argued that T. rex was a solitary, dumb beast, these new findings suggest that it may have been a clever social animal working in packs. This is confirmed by other studies that found mass burial sites in Utah and Montana, indicating that the carnivores moved in groups like wolves, as well as by the discovery of other fossils of male therapods guarding clutches of eggs (a social behavior frequently seen in modern birds).
Herculano-Houzel’s investigations hinge on treating theropods as a separate, warm-blooded group of dinosaurs – which may even have had feathers – instead of lumping T. rex and its relatives with all the rest of the dinosaurs. However, further research is needed to unearth more evidence of T. rex’s rich cognitive and social capacities.
“If they were hunters, maybe you find evidence of them hunting in groups, using some sort of social communication,” Herculano-Houzel concluded.
The study is published in the Journal of Comparative Neurology.
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By Andrei Ionescu, Earth.com Staff Writer
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