A little dinosaur called Shuvuuia may have hunted in the dark using night vision and super hearing.
This chicken-sized therapod lived in the deserts of what is now Mongolia. Its skeleton has a seemingly fragile bird-looking skull and brawny arms with only a single claw. It also had long roadrunner-like legs.
The team of researchers, led by Jonah Choiniere and James Neenan of the University of Witwatersrand, South Africa, found the length of the Shuvuuia’s lagena (a cochlea-like organ birds have to process incoming sound) was very similar in relative size to the barn owl, which is an excellent night hunter with extraordinary hearing.
The team used CT scanning of 100 living birds and extinct dinosaurs to compare lagena size, and digitally reconstructed the organs of each. The Shuvuuia’s large lagena was surprising.
3D reconstruction of the Shuvuuia deserti skull showing the lagena. The size suggests the dinosaur hunted at night. Credit: Jonah Choiniere/Wits University.
“As I was digitally reconstructing the Shuvuuia skull, I couldn’t believe the lagena size. I called Prof. Choiniere to have a look,” explains Neenan. “We both thought it might be a mistake, so I processed the other ear – only then did we realise what a cool discovery we had on our hands!”
“I couldn’t believe what I was seeing when I got there – dinosaur ears weren’t supposed to look like that!” says Choiniere.
Combined with superior hearing, the little therapod also had unusually large pupils, which may have helped it see in darkness and therefore hunt at night. The authors propose the Shuvuuia was a night-forager that used its eyes and ears to locate small mammals and insects, and then rapidly chased its prey with its lanky legs, using its brawny arms dig or snatch prey from burrows or shrubbery.
“Nocturnal activity, digging ability, and long hind limbs are all features of animals that live in deserts today,” says Choiniere, “but it’s surprising to see them all combined in a single dinosaur species that lived more than 65 million years ago.”
Artists reconstruction of Shuvuuia deserti. Credit: Viktor Radermaker. 
Artist’s reconstruction of Shuvuuia deserti. Credit: Viktor Radermaker 
Prof. Jonah Choiniere holding a 3D printed model of the lagena of Shuvuuia deserti. Credit: Jonah Choiniere/Wits University. 
Photograph of fossilized Shuvuuia deserti skeleton. Credit: Mick Ellison-AMNH. 
Photograph of fossilized Shuvuuia deserti skeleton. Credit: Mick Ellison-AMNH. 
3D model of a Barn owl skull illustrating the scleral ring and lagena. Credit: 3D model of a Barn owl skull illustrating the scleral ring and lagena. 
CT scan of a Barn owl skull illustrating the lagena. Credit: Jonah Choiniere/Wits University 
4. CT scan of a Shuvuuia deserti skull CT scan illustrating the lagena. Credit: CT scan of a Shuvuuia deserti skull CT scan illustrating the lagena