Oldest Fossilized Vomit Reveals Ancient Predator’s Meal & Ecosystem Snapshot

Approximately 290 million years ago, a predator living in what is now central Germany experienced an upset stomach – and inadvertently provided scientists with a rare glimpse into the ancient food web. Paleontologists have discovered the oldest known fossilized vomit from a land-based ecosystem, a lime-sized specimen containing the partially digested remains of at least three animals.

The find, detailed in a study published January 30 in Scientific Reports, offers a unique “photograph of a moment in the past,” according to Arnaud Rebillard, a paleontologist at Museum für Naturkunde in Berlin. “Any data that we can find about their behavior is very precious,” he said.

The fossil, unearthed in 2021 at the Bromacker locality in Germany, consists of a cluster of 41 bones, with researchers able to identify remains from two small, lizard-like reptiles and a limb bone from a larger, herbivorous reptile. The presence of multiple prey items suggests the predator wasn’t particularly selective in its diet, consuming whatever was available.

While the exact identity of the predator remains uncertain, scientists believe it was likely either Dimetrodon teutonis, characterized by a prominent sail on its back, or Tambacarnifex unguifalcatus. It’s important to note that despite their reptilian appearance, these animals were synapsids – a group that includes mammals and their extinct relatives, not dinosaurs.

The researchers determined the specimen was indeed vomit, and not fossilized feces (coprolite), through careful chemical analysis. The material surrounding the bones was found to be low in phosphorus, a characteristic not typically found in droppings. The 3-D scans of the bones further supported this conclusion, revealing a jumbled arrangement consistent with the contents of a gut.

The significance of this discovery extends beyond simply identifying what an ancient predator ate. “Because the fossilized vomit… contains three different animals eaten by one predator, we can literally say, for sure, that these three animals were living at exactly the same place and exactly the same time, maybe to the week or even to the day,” Rebillard explained.

The act of regurgitation itself is common in modern predators, who often expel indigestible materials like bones, fur, or feathers. While the reason for this ancient predator’s expulsion remains speculative, Rebillard suggests it could have been due to difficulty digesting the bones or simply overeating.

Fossilized digestive products, like regurgitalites and coprolites, are invaluable tools for understanding ancient ecosystems. “We need fossils like this to really tie together how the ecosystem functioned and how the food webs were structured,” says Martin Qvarnström, a paleontologist at Uppsala University in Sweden, who was not involved in the study.

The Bromacker site is particularly noteworthy because it preserves a snapshot of an early terrestrial ecosystem. Prior to the Permian period, land-based predators often inhabited semiaquatic environments, preying on crustaceans and fish. The Permian period marked a shift, with the emergence of larger herbivores in inland areas and, new predators to hunt them. Fossil evidence of these interactions is rarer in terrestrial settings, making the German find all the more significant.

This discovery provides a rare window into a time when terrestrial ecosystems were becoming more complex. “We’re talking about almost 300-million-year-old ecosystems,” Rebillard says. “So to have such a temporal vision about this to the day they were living, in the same area and the same moment, is extremely fascinating.” The fossilized vomit serves as a tangible link to a distant past, offering insights into the lives and interactions of creatures that roamed the Earth long before the age of dinosaurs.