King of the predators not all that clever, says study

TYRANNOSAURUS rex was not as clever as previously claimed, according to new research.

The king of the predators was as smart as reptiles today – but not as intelligent as monkeys, suggests the study.

An international team, including researchers at Bristol University and the University of Southampton, has re-examined brain size and structure in dinosaurs and concluded they behaved more like today’s crocodiles and lizards.

The research follows a study last year that claimed that dinosaurs such as Tyrannosaurus rex had an “exceptionally high” number of neurons and were substantially more intelligent than assumed.

It was claimed that the high neuron counts could directly inform on intelligence, metabolism and life history, and that T. rex was rather monkey-like in some of its habits.

Tool use and even cultural transmission of knowledge were cited as examples of cognitive traits that T. rex might have possessed.

But the new study, involving palaeontologists, behavioural scientists and neurologists, took a closer look at techniques used to predict both brain size and neuron numbers in dinosaurs.

The team found that previous assumptions about brain size in dinosaurs, and the number of neurons their brains contained, were unreliable.

The research, published in The Anatomical Record, follows decades of analysis in which palaeontologists and biologists have examined dinosaur brain size and anatomy, and used the data to infer behaviour and lifestyle. Information on dinosaur brains came from mineral infillings of the brain cavity, termed endocasts, as well as the shapes of the cavities themselves.

The researchers found that their brain size had been “overestimated” – especially that of the forebrain – and the neuron counts as well.

The new findings also show that neuron count estimates are not a reliable guide to intelligence.

To reliably reconstruct the biology of long-extinct species, the team argues, researchers should look at multiple lines of evidence, including skeletal anatomy, bone histology, the behaviour of living relatives and trace fossils.

Hady George, a PhD student at Bristol University, said: “Determining the intelligence of dinosaurs and other extinct animals is best done using many lines of evidence ranging from gross anatomy to fossil footprints instead of relying on neuron number estimates alone.”

Dr Darren Naish, of the University of Southampton, added: “The possibility that T. rex might have been as intelligent as a baboon is fascinating and terrifying, with the potential to reinvent our view of the past.

“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.”