IT’S already the dinosaur of nightmares – now it seems Tyrannosaurus rex might have been able to hunt after dark.

The eyes of T. rex face forward, giving them stereoscopic vision for seeking prey. Robert Bakker at the Houston Museum of Natural Science in Texas has found evidence that their ears might also have been focused forward, like those of some modern-day owls.

For many years, Bakker puzzled over a shelf-like ridge at the back of T. rex skulls. Unlike ridges that functioned as muscle-attachment sites, this feature is smooth, implying that it had another purpose, he says.


Finally, he realised that the ridge runs from the eardrum, positioned towards the back of the skull, to the front of the dinosaur’s cheek. “The most likely explanation is that there was an ear tube – an ear trumpet, if you will – that was concentrating hearing from the front,” he says.

“The most likely explanation is that an ear trumpet concentrated hearing from the front”

Resting on top of the ridge, this tube could have enabled tyrannosaurs to precisely pinpoint sounds directly in front of them. Dogs and cats do this by turning their external ears, but T. rex would have been more like some owls or hawks that lack external ears but use their feathers to channel sound from the front of their heads to their eardrums. This could have given tyrannosaurs the option to hunt in low light, says Bakker, whose team presented its findings at a meeting of the Geological Society of America in Baltimore, Maryland, this week.

It’s a plausible idea, says Philip Currie at the University of Alberta in Canada. But the ridge could simply have been there to reinforce the bone against pulling from muscles attached somewhere else, he says.

To know for sure if the ear tube existed, we need skull fossils with intact skin. Well-preserved fossils with skin have been found in China, so Bakker is optimistic. “Sooner or later they’ll get one,” he says.

Image credit: Pete Turner/Getty

This article appeared in print under the headline “T. rex may have hunted after dark like an owl”