Today, barn owls, bats, leopards and many other animals rely on their keen senses to live and hunt under the dim light of stars. These nighttime specialists avoid the competition of daylight hours, hunting their prey under the cloak of darkness, often using a combination of night vision and acute hearing.
But was there nightlife 100 million years ago? In a world without owls or leopards, were dinosaurs working the night shift? If so, what senses did they use to find food and avoid predators in the darkness? To better understand the senses of the dinosaur ancestors of birds, our team of paleontologists and paleobiologists scoured research papers and museum collections looking for fossils that preserved delicate eye and ear structures. And we found some.
Using scans of fossilized dinosaur skulls, in a paper published in the journal Science on May 6, 2021, we describe the most convincing evidence to date for nocturnal dinosaurs. Two fossil species – Haplocheirus sollers and Shuvuuia deserti – likely had extremely good night vision. But our work also shows that S. deserti also had incredibly sensitive hearing similar to modern-day owls. This is the first time these two traits have been found in the same fossil, suggesting that this small, desert-dwelling dinosaur that lived in ancient Mongolia was probably a specialized night-hunter of insects and small mammals.
