TORONTO -- About 10 million years before the T. rex roamed the lands of Alberta, another tyrannosaur, Daspletosaurus, called the land home, and now Canadian researchers have an idea of what its brain was like.
Scientists in Canada and Argentina used CT scans in an effort to reconstruct the brain, inner ear and surrounding bones, known as the braincase, of two well-preserved specimens of the nine-metre-long dinosaur.
The results, which were published Thursday in the Canadian Journal of Earth Sciences, oppose the predominant belief that dinosaur brains and braincases varied little between dinosaurs and related species.
“Our study with the two Daspletosaurus specimens suggests otherwise,” Tetsuto Miyashita, palaeontologist with the Canadian Museum of Nature and senior author of the study, said in a press release.
The digital reconstructions of the two Daspletosaurus brains could show that they come from difference species of the daspletosaurs, Miyashita added.
“We know that tyrannosaurs had relatively good-sized brains for a dinosaur, and this study shows that this pattern holds for Daspletosaurus," he said. "Furthermore, based on the shapes of the brain, ear structure, and braincase, we suggest that these two specimens represent distinct species of daspletosaurs.”
According to the press release, it's not common to look at and model braincases of multiple dinosaur specimens due to the hundreds of hours of work and medical technology, such as a CT scanner, required to access the braincase. Most braincase studies use one specimen from a representative species of the group.
The specimens used for the study were both discovered and remain in Canada. One is displayed in the Canadian Museum of Nature in Ottawa. It was found in 1921 near Alberta's Red Deer River. The second specimen, found in 2001, is with the Royal Tyrrell Museum of Palaeontology in Alberta.
Dinosaur braincase expert in Argentina and co-author of the study at the Instituto de Investigations en Biodiversidad y Medioambient, Ariana Paulina Carabajal, provided detailed models of the brain, inner ear and braincase. The researchers found that there were large bony canals that would have housed nerves to move the eyeballs, and also large air sacs that filled most of the braincase bones.
“These cavities within the bones not only make the huge skull lighter, but also are related to the middle region of the ear,” Paulina Carabajal said in the press release. “The cavities probably helped to amplify sound and assist the system that communicates to the left and right ears, allowing the brain to determine where a sound is coming from.”
The researchers say that their findings are good reason to study more braincases because even though the skeletons looked quite similar the results told a different story.
“Researchers have looked inside so few braincases in dinosaurs, typically one each for whatever species they studied, that this reinforced the assumption that these structures don’t change much within and among species," he said. "We just haven’t looked inside enough skulls to document variation.”
https://news.google.com/__i/rss/rd/articles/CBMifGh0dHBzOi8vd3d3LmN0dm5ld3MuY2Evc2NpLXRlY2gvdHlyYW5ub3NhdXItYnJhaW5zLXZhcmllZC1tb3JlLXdpdGhpbi1zcGVjaWVzLXRoYW4tcHJldmlvdXNseS10aG91Z2h0LW5ldy1yZXNlYXJjaC0xLjU1NTM4NDfSAUJodHRwczovL2JldGEuY3R2bmV3cy5jYS9uYXRpb25hbC9zY2ktdGVjaC8yMDIxLzgvMTkvMV81NTUzODQ3Lmh0bWw?oc=5
2021-08-19 20:00:00Z
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