An artist’s drawing of a puffin trying to sneak up on a frog floating on the surface of a pond while another cup replenishes part of a recent meal of frogs and newts. The puffin is the suspected predator of a 150-million-year-old vomit fossil discovered in southeastern Utah. (Brian Ing via the Utah Department of State Parks)
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VERNAL – A fossil recently discovered in southeastern Utah appears to show what type of prey predators were feeding on in the age of the dinosaurs and when the area wasn’t quite the desert it is today.
Paleontologists in Utah have discovered a pile of amphibian bones that they say looked like they had been regurgitated by some kind of predator. This prehistoric vomit is thought to be 150 million years old, according to paleontologists with the Utah Geological Survey, the Utah Department of State Parks, and the Flying Heritage & Combat Armor Museum in Washington.
Their findings were Published in Palaios magazine last month.
“This fossil gives us a rare glimpse into 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 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 is mostly known for its dinosaur bones, but it is also where scientists have found all kinds of other animals, such as fish, salamanders, and frogs.
The formation section of southeastern Utah is mostly characterized by prehistoric plants such as ginkgo, ferns, and conifers. However, paleontologists have also found amphibians and puffin fish there as well. These discoveries are the reason they believe the area was once home to a small pond or lake.
But during a recent survey, the team discovered an oddly arranged fossil. It was a set of bones that included “elements” from 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 group of bones in 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 within the regurgitalite. Foster notes that previous research places puffins in the area at the time, which he considers to be the “current best match” for the predator behind the fossil. Scientists have discovered fish, salamanders, and frog species in the Morrison Formation for more than a century.
“Although we can’t rule out other predators, the puffin is currently the suspect, so to speak,” he said, explaining that fish – and other animals – sometimes vomit their last meals when they are being pursued or want to distract a predator.
“There were three animals that we still have today, that interact in ways that are also known between those animals – prey eaten by predators and predators possibly being chased by other predators,” he added. “That in and of itself shows how similar some ancient ecosystems are to places on Earth today.”
This discovery is the latest to be made by the team in the region. Two of the three study co-authors are also assisting A huge 151 million-year-old aquatic insect has been discoveredwhich led to a paper published in 2020.
State paleontologist James Kirkland, who co-authored both studies, said paleontologists plan to continue searching 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 have found 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.”