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SPRING – A recently discovered fossil in southeastern Utah appears to show what kind of prey predators fed on during the age of dinosaurs and when the area wasn’t exactly the desert it is today. Paleontologists in Utah discovered a pile of amphibian bones that they say looked like they were suspended by some kind of predator. This prehistoric vomit is believed to be 150 million years old, according to paleontologists at the Utah Geological Survey, the Utah State Parks Department and the Museum of Flying Heritage & Combat Armor in Washington. Their findings were published in the journal Paleos last month. “This fossil gives us a rare look at animal interactions in ancient ecosystems,” John Foster, curator of the Utah State Field House Museum of Natural History and one of the study’s co-authors, said in a statement Tuesday. The team discovered the fossil while searching for the Morrison Formation, a famous fossil site known for its fossils from the late Jurassic period, which range from about 148 million years ago to 155 million years ago. It’s mostly known for its dinosaur bones, but it’s also where scientists have found all kinds of other animals, including fish, salamanders, and frogs. The southeastern Utah section of the formation is characterized primarily by prehistoric plants such as ginkgo, ferns, and conifers. However, paleontologists have also found amphibians and puffer fish there as well. These discoveries are why they believe the area was once home to a small lake or lake. But during a recent survey, the team discovered a strangely arranged fossil. It was a bone assemblage that included “evidence” of at least one small frog or tadpole and would be “the smallest salamander specimen reported from the formation,” the researchers wrote in the study. Some of these bones were only 0.12 inches long, among the smallest groups of bones in the formation. They added that the chemical and skeletal composition of the pit indicated that it was regurgitation, a fossilized form of vomit. The team notes that this is the first such discovery in the Morrison Formation and also in Jurassic North America. What is still not clear 150 million years later is what killed the species inside the reguitalite. Foster notes that previous research places bulges in the area around that time, which he believes are the “current best match” for the predator behind the fossil. Scientists have discovered species of fish, salamanders and frogs in the Morrison Formation for more than a century. “While we can’t rule out other predators, the bubble is currently the suspect,” he said, explaining that fish – and other animals – sometimes vomit their last meals when they’re being chased or want to distract a predator. . “There were three animals that we still have today that interacted in ways that are also known among these animals – prey being eaten by predators and prey possibly being hunted by other predators,” he added. “That alone shows how similar some ancient ecosystems are to places on Earth today.” This discovery is the latest made by the team in the region. Two of the study’s three co-authors are also helping. A 151-million-year-old giant aquatic insect has been discovered, leading to a paper published in 2020. State paleontologist James Kirkland, who co-authored both studies, said paleontologists plan to continue researching the site where prehistoric vomit was discovered to see if they can find more evidence of the area’s past ecosystem. “I was so excited to find this site, as Upper Jurassic vegetation sites are very rare,” he said in a statement. “Now we must carefully dissect the site looking for more little wonders among the foliage.” x

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Carter Williams is an award-winning reporter who covers general news, outdoors, history and sports for KSL.com. He was previously employed by the Deseret News. Transplanted to Utah by way of Rochester, New York.