Meet Troodon formosus: The bird-like thinker that may have been the smartest dinosaur to ever walk the Earth

When people think of dinosaurs, they often imagine gigantic predators such as Tyrannosaurus rex or the horned Triceratops, creatures defined by size, strength, and ferocity. For many years, dinosaurs were viewed as powerful but primitive animals that relied on instinct rather than intellect.Modern science, however, paints a very different picture. Since today’s birds are the direct descendants of small, feathered dinosaurs, palaeontologists have begun studying avian intelligence to better understand how these prehistoric creatures may have thought and behaved.Birds like crows, parrots, and ravens show remarkable intelligence. They can solve puzzles, use tools, mimic speech, and even display social cooperation during hunting.

These abilities suggest that their dinosaur ancestors might also have possessed complex mental capacities. Among the many dinosaurs that once roamed the Earth, one species stands out as an exceptional thinker. Troodon formosus, a small but clever predator, is now believed to have been one of the most intelligent dinosaurs that ever lived.

How Troodon formosus survived in the Cretaceous world

Troodon formosus lived approximately 79 to 75 million years ago during the Late Cretaceous period in what is now North America.

Fossil evidence from regions such as Montana and Alberta shows that this species thrived in lush floodplains and ancient forests.Despite its fearsome name, Troodon was not a giant. It grew to around eight feet in length and weighed about 50 kilograms, roughly the size of a modern wolf. Its lean body, long legs, and stiff tail suggest it was a swift and agile runner, capable of moving quickly to capture prey or escape larger predators.The name Troodon means “beautiful wounding tooth,” a reference to its uniquely serrated, backward-curving teeth. These teeth had characteristics of both meat-eaters and plant-eaters, leading scientists to believe that Troodon was likely omnivorous. It probably hunted small animals and insects, raided nests for eggs, and may have occasionally eaten vegetation.This flexibility in diet, combined with agility and sharp senses, would have made Troodon a resourceful and adaptable hunter in a dangerous ecosystem.

How Troodon formosus showed signs of bird-like intelligence

The most extraordinary feature of Troodon was its brain. When scientists studied its skull, they discovered that the braincase was unusually large compared to its body size. To assess potential intelligence, researchers use the encephalisation quotient (EQ), which measures the ratio between brain and body mass.According to Dr David Varricchio of Montana State University, “Among dinosaurs, Troodon and its relatives have relatively large brains.”Its EQ was several times higher than that of massive predators such as T. rex and Allosaurus, and similar to that of modern flightless birds like emus and ostriches. Inside its skull, scientists found large cerebral hemispheres responsible for decision-making and problem-solving, as well as enlarged optic lobes that indicate strong visual processing.This combination of size and structure shows that Troodon’s brain was not only large but also organised in a way that resembles birds more than reptiles.

It was a sign of evolutionary progress towards more complex thinking and awareness.

Troodon formosus: How it used its eyes and hands to hunt

Another striking aspect of Troodon was its vision. Fossil evidence reveals that it had very large eye sockets, suggesting excellent night vision. Its eyes faced forward, giving it binocular vision and the ability to judge distance and depth accurately, which would have been essential for a predator tracking fast-moving prey.Dr Varricchio confirmed that Troodon had both large eyes and some degree of binocular vision.

Although sharp eyesight alone does not prove high intelligence, it demonstrates an advanced level of sensory adaptation. Combined with its large, complex brain, Troodon’s keen vision made it one of the most perceptive hunters of its time. Troodon’s hands also reveal clues about its intelligence. Unlike most dinosaurs, it had flexible wrists and long, curved claws that may have allowed it to grasp prey or manipulate objects.Earlier studies by palaeontologist Dr Dale Russell suggested that Troodon might have had an opposable thumb, giving it the ability to hold items or even use tools. Later evidence suggests this was not entirely accurate, but the dinosaur did have a degree of grasping ability.Its hands were likely used to catch small animals, pick up eggs, or interact with its surroundings in ways that required precision and coordination.

These traits indicate a creature that relied on agility and strategy rather than brute strength.

Unravelling the mystery of Troodon formosus’s intelligence

Despite Troodon’s impressive brain and anatomy, scientists admit that measuring intelligence in extinct animals is a challenge. Intelligence involves problem-solving, communication, and social learning, which cannot be directly observed from fossils.“Brain size and form are well documented,” said Dr Varricchio, “but translating these attributes into ‘thinking’ or ‘smarts’ is difficult.”Even among living creatures, defining intelligence is complex. Comparing a crow, a cat, or a dolphin reveals that each species has evolved different forms of intelligence suited to its environment. Assessing the mental abilities of a dinosaur that lived 75 million years ago can therefore only be done in general terms.Nevertheless, based on what scientists do know, Troodon appears to have been among the most cognitively advanced dinosaurs ever discovered.

Troodon formosus and its evolutionary link to early birds

Compared with other small theropods such as Velociraptor and Microraptor, Troodon displayed a larger and more sophisticated brain. According to Dr Varricchio, Troodon was closely related to early birds, suggesting that its intelligence was part of an evolutionary trend among smaller feathered dinosaurs.By the end of the Cretaceous period, species like Troodon were already developing traits such as balance, coordination, and complex problem-solving abilities that would later become defining features of modern birds.

This evolutionary link shows how intelligence and adaptability were already beginning to shape the course of life long before the age of mammals.

Nesting behaviour and parental care

One of the strongest indicators of Troodon’s intelligence comes from its reproductive behaviour. Fossil evidence from Montana’s Two Medicine Formation reveals carefully arranged nests of Troodon eggs. These eggs were often half-buried in sediment, and the nesting sites suggest that adults may have guarded or incubated them. Such evidence suggests that Troodon was capable of parental instincts and social behaviour, making it one of the few dinosaurs to demonstrate advanced reproductive care.Also Read | China unveils ‘ghost jellyfish drone’ disappears into the deep sea, leaving people wondering what it’s watching underwater