Imagine a Tyrannosaurus rex stalking a herd of Triceratops on a humid Cretaceous afternoon. The massive predator sniffs the air, locks eyes on a lone Triceratops that has strayed from the group and plans its attack.

This familiar scene is a staple of countless books, movies and games, but how accurate is it? Recent advances in palaeontology and neuroscience are shedding new light on what it was really like to be a dinosaur, offering unprecedented insights into their sensory perception and behaviour.

For over two centuries, palaeontologists have debated the intelligence and sensory capabilities of dinosaurs.

Early theories, based on natural endocasts (fossilised impressions of brain cavities), suggested that dinosaurs had small brains and limited cognitive abilities. This led to amusing, and now debunked, ideas like the notion that Stegosaurus had a second brain near its tail to help manage its enormous body.

However, modern technology has revolutionised our understanding of dinosaur brains. With tools like micro computed tomography (CT) scanning, scientists can now create detailed 3D models of dinosaur brain cavities without damaging fossils. These models allow researchers to estimate brain volume, map brain regions, and infer the sensory abilities and cognitive functions of dinosaurs.

One of the most exciting developments comes from a study led by neuroscientist Suzana Herculano-Houzel of Vanderbilt University, who suggested that T. rex might have been as intelligent as a primate, like a baboon. This startling claim is based on the number of neurons in the brain’s telencephalon, a region associated with higher cognitive functions.

T. rex could have had around three billion neurons, placing it in the same league as some of today’s smarter animals

By comparing the brains of modern animals to those of dinosaurs, Herculano-Houzel estimated that T. rex could have had around three billion neurons, placing it in the same league as some of today’s smarter animals.

But was T. rex really a dinosaur genius? Other researchers urge caution. While the telencephalon of T. rex was indeed large, much of its brain was devoted to olfaction (sense of smell) rather than higher cognitive functions. This means that while T. rex likely had an exceptional sense of smell – useful for hunting – it may not have been capable of advanced planning or social behaviour like primates.

Further studies using CT scans have revealed that T. rex had large optic lobes, suggesting keen vision like that of modern birds of prey. Its forward-facing eyes likely provided it with excellent depth perception, crucial for accurately targeting prey. Additionally, its inner ear structure indicates that T. rex was well-adapted for rapid movement, though it was probably restricted to running rather than complex aerial manoeuvres.

Research on other dinosaurs, like the small theropod Shuvuuia, has shown that some species had adaptations for nocturnal hunting, like modern owls. These findings suggest that dinosaurs were highly diverse in their sensory abilities and ecological niches.

As palaeontologists continue to use advanced technology to study fossils, our understanding of dinosaur behaviour and sensory perception will only grow. What was once a world of slow-moving, dim-witted giants is now revealed as a dynamic ecosystem filled with complex, intelligent creatures, each uniquely adapted to its environment. So, the next time you picture a T. rex on the hunt, remember – it might have been far smarter and more perceptive than we ever imagined.

Mohamed Daoud is a public engagement expert.

Did you know?

• Birds are living dinosaurs: Modern birds are direct descendants of theropod dinosaurs, making them the closest living relatives of giants like T. rex.

• Dinosaurs had feathers: Many dinosaurs, including Velociraptor, had feathers. These early feathers may have been used for display, insulation or even gliding.

• Dinosaur colours: Fossilised pigment cells suggest some dinosaurs had vibrant colours and patterns, possibly used for camouflage, attracting mates, or intimidating rivals.

• T. rex’s powerful bite: T. rex had the strongest bite of any land animal ever, capable of crushing bones with a force of up to 5,800 kilos.

• Dinosaurs lived on every continent: Fossils have been found on all seven continents, including Antarctica, showing that dinosaurs lived in diverse environments.

• Long-necked giants: The largest dinosaurs, like Argentinosaurus, could reach lengths of over 30 metres. These sauropods were herbivores with long necks used to reach vegetation high in the trees.

For more trivia, see: www.um.edu.mt/think.

Cast of a Tyrannosaurus rex braincase at the Australian Museum, Sydney. Photo: Matt Martyniuk

Sound bites

• Researchers have discovered a more accurate and timely way to deliver life-saving drug therapies to the brain, laying the groundwork for more effective treatment of brain tumours and other neurological diseases. Investigators used an electric field to infuse medicine from a reservoir outside the brain to specific targets inside the brain. 

• Dinosaurs grew up fast, a feature that likely set them apart from many other animals in their Mesozoic (252 to 66 million years ago) ecosystems. Some researchers have proposed that these elevated growth rates were key to the global success of dinosaurs, but little is known about the growth strategies of the earliest dinosaurs.

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Photo of the week

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Actor Sean Briffa and scientist Eugene performing for the press launch of the Science in the City festival. This year’s theme is ‘J.E.D.I.’ and the festival will be packed with arts, music, robots, performances, experiments, VR/AR, a green area, street sports and much more. Pre-festival events September 7 to 24; street festival September 27–28 around Triton Fountain 6-11pm; performance festival September 27 4-11pm; September 28 10am–11pm. Free booking via https://bit.ly/SITCBOOK2024. Photo: Elisa Von Brockdorff