T Rex may have had brains ‘capable of using tools,’ ‘passing knowledge to kin,’ study claims

The giant predatory dinosaur Tyrannosaurus rex may have had “flexible cognition” that would place it in the realms of modern day tool-using and culture-building birds and primates, according to a new study.

The research, published recently in the Journal of Comparative Neurology, found that T rex may have had “baboon-like numbers of brain neurons” that would have made them not only giant predators but also brainy creatures.

Study author Suzana Herculano-Houzel from Vanderbilt University in the US says this level of brain neurons may have given the predatory dinosaur the potential abilities to solve problems and even build some tools.

With these abilities, she says the dinosaur may have lived up to 40 years, “enough to build a culture”.

“A culture is any body of knowledge and technology that gets passed down across generations and built upon. The more cognitively capable you are and the longer you live, the more opportunities to build one – and both come with more neurons,” Dr Herculano-Houzel explained in a tweet.

In the new research, the study’s sole author Dr Herculano-Houzel used data on modern-day birds and reptiles to estimate how number of neurons scales with increasing brain mass.

Based on this estimate, she extrapolated how many brain neurons T rex might have had, particularly in the more developed part of the brain, the telencephalon known to be responsible for cognition in animals.

The analysis found that T rex may have had about 3 billion cerebral neurons packed into its brain.

She says the dinosaur’s brain may have had more nerve cells than the number found in baboons, and may have been as “neuron-dense as primate brains – and ostrich and chicken brains.”

If these numbers were an indication of cognitive abilities, the neuroscientist say this “would make these animals not only giant but also long-lived and endowed with flexible cognition, and thus even more magnificent predators than previously thought”.

“An elephant-sized but agile carnivoran biped endowed with macaque- or baboon-like cognition must have been an extremely competent predator indeed,” she added.

The Vanderbilt University claims T rex may have matured fast – taking about 5 years to reach sexual maturity – and also lived over 40 years.

This may have been enough to build culture and passing on knowledge to its kin and the dinosaurs may have also been capable of using tools, Dr Herculano-Houzel says.

She concludes that T rex and other related theropod dinosaurs may have been “in the cognitive realm of tool-using and culture-building modern birds and primates.”

However, not all scientists are convinced of the study’s interpretations and call for further research including more data to substantiate the findings.

“Don’t get me wrong. T rex was probably smarter than we give it credit for, but tool use capabilities? That’s a very big claim to make,” paleontologist Tess Gallagher from the University of Bristol tweeted.

“Intelligence itself is already a difficult thing to study, let alone study the intelligence of an extinct taxon that is incapable of having its behaviour observed,” he added.

Paleontologist Thomas Holtz from the University of Maryland tweeted that “people should be very very very cautious about these conclusions,” adding that the “best evidence” for the onset of sexual maturity in Tyrannosaurus was around the age of 13-16.

“I’m not saying that the behavioural conclusions are demonstrably wrong. We can’t say that at this time,” he tweeted.