A group of scientists has disputed a study published last year that suggested the intelligence of the dinosaur Tyrannosaurus rex was similar to that of a baboon.
The group disputed last year’s report by Susanna Herculano-Housel of Vanderbilt University in Tennessee. It said the study did not use surveys of reptiles such as crocodiles and alligators to explain dinosaur brains.
Zoologist Kai Kaspar is from Heinrich Heine University in Germany. Caspar was the lead author of the new study, published in The anatomical record.
Speaking of dinosaurs like the T. rex, he said “their neuron the numbers were probably not exceptional, especially for animals of their body mass.
But Herculano-Housel stand aside her research.
She said her work examined “the relationship between brain and body size” in modern theropod relatives such as ostriches and chickens. The brain size and number of neurons in these animals, she said, support her theory.
Theropod is a group of dinosaurs that includes the T. rex.
She said only one question was disputed: “What was the actual brain size of the dinosaurs. Even then, we’re talking about the difference between a T. rex’s brain being the size of a baboon or a monkey.
Caspar said his research group also looked at modern birds.
“Reptiles certainly aren’t like that dim-witted as is commonly believed,” he said. Speaking of T. rex, he noted, “it was certainly behavioral complex animal.”
Caspar said he has additional concerns about Herculano-Housel’s research. One problem, he said, is that while humans, baboons, other mammals and even birds have brains that fill the space protected by skull“this is not the case with reptiles kinds.” He noted that the reptilian brain fills only about 30 to 50 percent of the space.
He also said that it is not known how many neurons, or brain cells, were present in dinosaur brains.
“Looking at living animals, we see that the number of neurons is actually not good indicator intelligence first,” Kaspar added.
Caspar noted the 2023 survey supposed the brain fills the entire skull, which, he said, “is certainly not the case.”
Scientists have been studying dinosaurs for about 200 years. But much remains to be discovered.
Thomas Holz is a co-author of the new study. He studied dinosaurs at the University of Maryland. He said it is difficult to assess the intelligence of animals that lived more than 60 million years ago.
“It would be nice if we could calculate just one number and untangle all the complexity of animal biology and lifestyle, but nature is not like that,” Holtz said.
He said T. rex probably had an intelligence level somewhere between that of birds and reptiles.
“A lot of our general assumptions don’t really hold up when you … examine what real animals do in the real world,” he said.
I’m Dan Friedel.
Dan Friedl adapted this story for Learning English based on a Reuters report.
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Words in this story
reptile -n. a class of animals with a backbone that lays eggs, is covered with scaly skin, and has a low body temperature
neuron -n. a special cell of the nervous system of many animals
ready -v. (phrasal) to support or continue to support even though there is opposition
dim-witted – adj. is not intelligent
complex – adj. extremely clever or sophisticated
kinds -n. a group of animals or plants that can have offspring with each other and is a group smaller than a genus
skull -n. the bones of the head
indicator -n. something that indicates the presence of something else
I guess –v. to think something is true without fully knowing or confirming it
untangle -v. to take apart or separate something in an attempt to understand it
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