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Fantastic dinosaurs that hunted in the dark

Shuvuuia Deserti Restoration Plant

A remake of artist Shuvuuia deserti.Credits: Viktor Radermaker.

Shuvuuia, a tiny desert dino, has extraordinary vision and owl-like hearing for night life in the Mongolian desert.

Today there are 10,000 bird species living in almost every habitat on the planet. But only a few of the species have adapted so they can hunt more active prey at night. Scientists have long wondered whether the pteropod dinosaurs, the group that gave rise to modern birds, had similar sensory adaptations.

A new study led by scientists from the university. Witwatersrand Professor Jonah Choiniere sought to examine the sight and hearing of dinosaurs and birds as compared to each other. An international team of researchers used CT scans and detailed measurements to collect data on the size of the eyes and inner ears of nearly 100 living birds and extinct dinosaurs.

The new creation of Shuvuuia Dessert Artist

A remake of artist Shuvuuia deserti.Credits: Viktor Radermaker.

To measure hearing, the team measured the length of lagena, the organ that processes incoming sound information. (Called a mammalian cochlea) a barn owl, which can hunt in complete darkness using only hearing, has the longest lagina of any bird species.

To assess vision, the team looked at the scleral ring, a set of bones surrounding the pupil of each species. Like a camera lens, the wider the pupil opens, the more light gets into it, giving you better vision at night. By measuring the diameter of a ring, scientists can tell how much light the eye can collect.

The team found that many carnivorous theropods, such as Tyrannosaurus and Dromaeosaurus Having ideal daytime vision and better-than-average hearing should aid in hunting, however, a small theropod, named Shuvuuia, which is part of a group called alvarezsaurs, has both extraordinary hearing and hearing loss. See at night The very large lagena of this species is almost the same size as today’s barn owl, indicating that Shuvuuia can hunt in complete darkness.

Shuvuuia’s huge Lagena was a surprising discovery for Dr. “While I was digitally recreating the Shuvuuia skull, I couldn’t believe it was the size of Lagena… I called Prof Choi Nière. We both thought it might be a mistake, so I processed the other ear – and then we realized how great a find was in our hands! ”I couldn’t believe what I saw when. I got there – dinosaur ears weren’t supposed to be like that! ”Said Choiniere.

Shuvuuia’s eyesight was also observed, as they had the largest, proportional pupils yet measured in birds or dinosaurs, indicating that they were likely to see well at night.

Jonah Choiniere Shuvuuia Desert

Professor Jonah Schoenière holds a 3D print of the Lahena of the Shuva Uea Desert.Credits: Wits University.

Shuvuuia was a tiny chicken the size of a dinosaur and lived in the desert of present-day Mongolia. Shuvuuia’s skeleton is one of the strangest of all dinosaurs – it has a fragile, bird-like skull, strong lifters arms, one claw in each hand, and a roadrunner-like long legs. This bizarre combination of features has puzzled scientists since its discovery in 1990 with new Shuvuuia sensory data.The science team hypothesized that, like many desert animals, Shuvuuia would be nocturnal by: Use hearing and vision to find prey such as small mammals and insects, using long legs to run down quickly. And use strong legs to pry prey out of burrows or bushy plants.

“Nocturnal activity, digging ability and long hind limbs are typical of today’s desert-dwelling animals,” says Chonière, “but it’s surprising to see them all together as a late dinosaur. The only species that lived more than 65 million years ago “

Reference: “Evolution of Vision and Hearing in Terropod Dinosaurs” by Jonah N. Choiniere, James M. Neenan, Lars Schmitz, David P. Ford, Kimberley EJ Chapelle, Amy M. Balanoff, Justin S. Sipla, Justin A. Georgi, Stig A. Walsh, Mark A. Norell, Xing Xu, James M. Clark, and Roger BJ Benson May 7, 2021. science.
DOI: 10.1126 / science.abe7941

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