New Delhi, India

Dinosaurs, the mighty beasts that once roamed the planet, are known for their reptilian appearance, or rather what we believe they looked like. For a long time, scientists have also speculated that dinosaurs were sluggish, cold-blooded creatures that, like lizards, depended on external heat sources to help regulate their body temperatures.

Advertisment

This view began to shift as research suggested some dinosaurs could regulate their body temperatures. However, the timing and mechanisms of this transformation remained unclear.

However, new research may have managed to estimate the time these mighty beasts gained semblance of control over their body temperatures.

Also read | Megatitanosaur 'Shiva the destroyer' discovered in Argentina. This is what it looked like. Watch!

Advertisment

Once upon a time

The study published Wednesday (May 15) in the journal Current Biology estimates that the first warm-blooded dinosaurs emerged around 180 million years ago, roughly halfway through their reign on Earth.

To pinpoint the origins of warm-blooded dinosaurs, researchers analysed over 1,000 fossils, climate models, and dinosaur phylogenies. 

Advertisment

They discovered that two major dinosaur groups—those including Tyrannosaurus rex and velociraptors, as well as the relatives of triceratops—migrated to colder regions during the Early Jurassic period. This migration suggests these dinosaurs may have evolved mechanisms to stay warm. Meanwhile, a third group, including brontosaurs, remained in warmer climates.

"If something is capable of living in the Arctic, or very cold regions, it must have some way of heating up," explained Alfio Alessandro Chiarenza, a study author and postdoctoral fellow at University College London.

Whether dinosaurs were warm-blooded or cold-blooded, why does it matter?

Warm-blooded animals, such as birds — proven descendants of dinosaurs — and even humans, maintain a constant body temperature regardless of external conditions.

Also read | Ancient fossil shows birds are officially dinosaurs 

In contrast, cold-blooded animals, like reptiles, rely on environmental heat sources like the sun to regulate their body temperature.

Jasmina Wiemann, a postdoctoral fellow at the Field Museum in Chicago, noted that a dinosaur's habitat is just one factor in determining its thermoregulation capabilities. Wiemann's research, which was not involved in this latest study, suggests that warm-bloodedness in dinosaurs might have evolved even earlier, around 250 million years ago, near the beginning of their existence.

Wiemann emphasised that compiling various clues from dinosaurs' lives, including body temperatures and dietary habits, could help scientists better understand when warm-bloodedness evolved. 

Understanding when dinosaurs developed warm-bloodedness can provide insights into their behaviour, activity levels, and social structures. 

(With inputs from agencies)