About 110 million years ago, an apparent dinosaur ate two pterosaurs and four fish and, for whatever reason, threw them back up. A rare mix of geological conditions has preserved this dinosaur’s vomit for human researchers to dig up—only for the researchers to catalog it as fish remains, nothing special.
It wasn’t until paleontologist Aline Ghilardi of the Federal University of Rio Grande do Norte in Brazil and her colleagues took a closer look that they realized the fossil was so strange and detailed that it couldn’t just be a fish. His suspicions were correct. The fossil contains the remains of an entirely new pterosaur – the first extinct species to be discovered inside a fossilized vomit.
Pterosaur, named after Bakiribu Waridza“This unique combination of jaw and teeth features was not present in any known pterosaur,” Gilardi, senior author of the recent Scientific Reports paper describing the findings, told Gizmodo in an email. He said it was also the first time that a rare filter-feeding pterosaur group, the ctenochasmatids, had been discovered in Brazil or in rocks of this age.
How does vomit become fossilized?
Bromelites – fossilized digestive remains such as coprolites (feces) and regurgitates (vomit) – are very rare but do exist. However, according to Gilardi, survival for hundreds of millions of years requires very specific conditions for regeneration. First, vomit has to be suppressed very rapidly in a quiet, low-energy environment, and the mucus that binds the contents together has to stop over time.
“Otherwise, they get destroyed by rain, waves, wind or scavengers, or simply fall apart,” she said. The material inside is often partially processed or fragmented, meaning that paleontologists often need to perform thorough microscopic examinations of the remains.
separating the “fish”
However, in this case, the pterosaur remains were surprisingly clear and recognizable; Ghilardi and his colleagues were almost immediately able to identify signs resembling “very strange teeth of ctenochasmatid pterosaurs,” he recalls.
However, given the rarity of these pterosaurs, the team was hesitant to call it a new discovery. In fact, he did not even realize that the fossil itself was a reborn, although he noticed that the style and arrangement of the bones was extremely unusual.
After a few rounds of careful checking, which included cross-referencing the photographs with other colleagues, the team decided to examine the fossil in more detail. He considered various candidates for what the fossil might be, but once he considered that it might be a reburial consisting of pterosaur bones, “the pieces began to fall into place”, Ghilardi said, adding, “What surprised me most was how an apparently normal specimen ended up containing something completely unexpected.”
The unusually clean preservation of the bones also enabled the team to paint a detailed picture of Bakiribu Waridza According to the paper, this is what it might have looked like: Long jaws densely populated with long, thin teeth, shedding “new light on the evolutionary trajectory of filter-feeding pterosaurs”. These pterosaurs may have consumed food somewhat like modern flamingos. Researchers are not sure yet whose vomit it was.
Additionally, it represents another paleontological “rediscovery” in which new information has been revealed about a fossil previously excavated by modern methods. For example, the new pterosaur sat in the Museu Câmara Cascudo in northeastern Brazil for decades, until Gilardi’s team more or less nailed down its unique structure.
“Moments like this remind us why paleontology feels so magical,” Gilardi said. “Extraordinary discoveries may be quietly hidden in museum drawers, waiting for the right moment to reveal themselves.”