The little dinosaur, about the size of a chicken (just 0.6 meters long) and looking like a bird, lived in the Mongolian desert more than 65 million years ago and had truly extraordinary night vision . reveals a new study on his remains.
Shuvuuia, the dinosaur in question, was a theropod, a group of dinosaurs characterized by hollow bones and three-toed limbs, which also includes the famous and not at all small, Tyrannosaurus rex.
Researchers have determined that the dinosaur had proportionally larger pupils than any other dinosaur ever studied or even modern birds . And that of the 10,000 species of birds that currently inhabit our planet, only a few have qualities that allow them to actively hunt in dark conditions. Now, thanks to this discovery made by scientists at the Institute for Evolutionary Studies at Wits University in Johannesburg, we know that this mini-dinosaur of more than 65 million years, from which the birds descended, was able to do just that: hunt under the dark cloak. of the night.
The international team of scientists used CT scans and detailed measurements to gather information on the relative size of the eyes and inner ears of nearly 100 species of living birds and extinct dinosaurs. To assess vision, they looked at the scleral ring, a series of bones that surround the pupil, of each species. Like a camera lens, the larger the pupil can be opened, the more light can enter, allowing for better vision at night.
It turned out that his hearing and night vision were extraordinary. The extremely large lagena of this species – the organ that processes information from incoming sound – is nearly identical in relative size to today’s barn owl, suggesting that Shuvuuia may have hunted in complete darkness.
A rare dinosaur
Shuvuuia was discovered more than 20 years ago but there were still things about him that we did not know. Researchers have always been fascinated by this dinosaur, for its small size and strange appearance. With a fragile skull similar to that of a bird, but with muscular arms with a single claw on each hand and long legs as if it were a roadrunner , it is a fossil that cannot but attract attention due to its strange combination of characteristics.
After analyzing his remains, experts have determined that Shuvuuia would have searched for food at night, using his hearing and vision – as if it were an owl – to find prey such as small mammals and insects. It would also have used its long legs to quickly reach its prey, and its strong forelimbs to pull prey out of burrows or shrubby vegetation.
“Nocturnal activity, digging ability and long hind legs are characteristic of animals that live in deserts today,” says Jonah Choiniere of the University of the Witwatersrand in Johannesburg, South Africa and leader of the study published in the journal Science. . “But it is surprising to see them all combined into a single species of dinosaur that lived more than 65 million years ago.”
Referencia: J.N. Choiniere el al., “Evolution of vision and hearing modalities in theropod dinosaurs ,” Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abe7941
