Dear Mummy- Rare fossil reveals common dinosaur

2022-04-13
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Dear Mummy: Rare fossil reveals common dinosaurs soft tissue A mummified dinosaur unearthed in Montana a year ago is giving scientists a rare peek at what the creatures muscles and other soft tissues may have looked like. SOLID DISCOVERY. Tissues preserved in Leonardo but rarely found in other fossils include a beak (lower left), throat tissues, and shoulder muscle (labeled 3). M. Thompson/Phillips County MuseumThe duck-billed animal–dubbed Leonardo by its discoverers–would have been about 7 meters long and weighed about 2 tons when it traipsed around Montana in large herds about 77 million years ago. The most complete mummified dinosaur to be described in 70 years, the fossil includes three-dimensional, mineralized casts of the animals right shoulder muscle, throat tissue, and skin. Much of the left side of the dinosaur was relatively flattened, with skin drawn taut against ribs and other bones. Sign Up For the Latest from Science NewsHeadlines and summaries of the latest Science News articles, delivered to your inbox Thank you for signing up! There was a problem signing you up. Leonardo, the first reported young adult of a species called Brachylophosaurus canadensis, is more than 90 percent complete, says Nate L. Murphy, curator of paleontology at the Phillips County Museum in Malta, Mont. More than 80 percent of Leonardos skin is intact. That made it difficult to decide where to cut the fossil apart during excavation, says Murphy. He and his colleagues ultimately unearthed the find in a single, 6.5-ton block of sandstone. A piece of fossilized skin that fell from Leonardos side while researchers prepared the specimen for exhibition provided a look at the dinosaurs last meal. Preliminary analyses suggest magnolia and conifer, says Murphy. Pollen and spores in the last meal came from ferns and liverwort, which grow in subtropical environments. Murphy and his colleagues described their find last week at the Society of Vertebrate Paleontology meeting in Norman, Okla. The presence of liverwort, a plant that cant survive even a short period of dry conditions, strongly suggests that Leonardos mummification didnt result primarily from desiccation. If the environment was really hot and humid, finding Leonardo would be the equivalent of stumbling across a long-dead but intact elephant in a steamy tropical jungle, says Michael J. Everhart of Fort Hays State University in Hays, Kansas. Something had to shut down the normal process of decomposition within just a few days, he notes. Its difficult to explain. The sediments surrounding Leonardo suggest that when the animal died, it fell onto a sandbar along an ancient river, says Murphy. Its possible that minerals in the river infiltrated the dinosaurs soft tissues, preserving them after the animal was buried in the riverbed, he notes. Whatever happened, the mummification process also preserved a network of tendons and a frill–like a roosters comb–that ran along the creatures back. Leonardo will be a great test of how scientists have imagined dinosaurs to appear, Murphy says. Everhart agrees: The information locked in this specimen will take years to dig out and interpret. **************** If you have a comment on this article that you would like considered for publication in Science News, please send it to editors@sciencenews.org.

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