Sometimes, the most important paleontological discoveries may come from the most disgusting materials.
In 2021, paleontologists discovered a specimen in Bromacker, Germany, that dates to the early Permian period, approximately 290 million years old. To an untrained eye, the specimen wouldn’t be more than just a few whitish bits of densely packed bones in sandstone and sediment. But experts recognized those clustered fragments as the fossilized vomit of an ancient creature, holding insights into its diet, physiology, food chain, and ecosystem.
Finding the bones compactly clustered was “so far really new and unique. I was really surprised to see this,” the co-author of the study, Arnaud Rebillard at Museum für Naturkunde in Berlin, told Refractor in an interview. “I immediately thought that it may be something that has been expelled from a predator.”
The specimen, named MNG 17001, is an irregularly shaped, three-dimensionally preserved cluster, measuring roughly 2 inches long, 1.2 inches cm wide, and 0.5 inches thick (5 cm x 3 cm x 1.4 cm). Using micro-CT scans, Rebillard and his colleagues digitally segmented the content to reveal the details without destroying the fossil itself.
The researchers identified a total of 41 tiny bones, all under 20mm, of at least three different animals. Thanks to extensive excavations made at the Bromacker site over the last 30 years, the team was able to compare the bones with other fossils found there.
Image courtesy of the researchers
Among the identifiable species, one of the bones belonged to Thuringothyris mahlendorffae, a small reptile. They also found an upper arm bone of Eudibamus cursoris, “which is quite an iconic animal from Brocker,” Rebillard told us. “Famous because it is a bipedal reptile.”
The third bone was bigger than the rest and corresponded to a metapodial element (a bone from the foot or hand). The data indicate that the creature belongs to an unidentified diadectid. “It was kind of a bulky, big animal that was around 60 cm (24 inches) long,” says Rebillard.
In the Bromacker locality, previously found fossil bones were scattered. However, MNG 17001 bore densely compacted bones, so the team hypothesized that an animal devoured three different animals, at least in parts, and then regurgitated them, i.e., vomited them. But the bone clump could also have been the result of feces (known as coprolite when it’s found in a fossilized state).
“So our goal was to identify ‘is that a coprolite or a regurgitalite?’,” the paleontologist told us. For a matrix to be a coprolite, the content should be enriched with phosphorus concentration, mainly due to the microbial activity during digestion. However, the X-ray fluorescence analysis showed no phosphorus around the bones.
Rebillard explains that, in regurgitalites, the matrix spends less time in the stomach, and therefore, it lacks the phosphorus concentration. After proving the remains as regurgitalites, it’s so far the earliest evidence of a vomit made on land from a vertebrate.
Since the animals were of different sizes, Rebillard notes that the predator that made this vomit was an opportunistic feeder, i.e., not a picky eater. It ate whatever prey was available.
“Discoveries like this help tell the story of predator versus prey in these ancient ecosystems,” says William Freimuth at NC State University, who wasn’t involved in the study. “In the context of the Bromacker locality, this regurgitalite is a crucial node in the food web of this important early Permian terrestrial ecosystem.”
The coprolites and regurgitalites are very important for us to reconstruct the story that happened back then. These fossils are like ‘time capsules’ that prove these animals coexisted, says the co-author of the study.
As for who ejected this clump, the study suggests two apex predators from the locality: Dimetrodon teutonis and Tambacarnifex unguifalcatus; both are synapsids, or ancestors of mammals.
“Generally speaking, regurgitalites are rare but paleoecologically significant fossils. The identification of this specimen as the oldest terrestrial regurgitalite from the famed Bromacker locality is highly significant,” Freimuth concludes.
The study has been published in Scientific Reports.
