Bakiribu waridza: The Pterosaur Found in a Pile of Prehistoric Vomit

The fossil sat on a museum shelf in Natal, Brazil for decades. It was cataloged, but not celebrated. A modest lump of stone from the Cretaceous Araripe Basin, it was officially labeled a regurgitalite—a fossilized mass of vomit. To most, it was a geologic curiosity. To Rodrigo Pêgas, a paleontologist with a gift for seeing past the obvious, it was a prison. And something magnificent was locked inside.

In November 2025, Pêgas and his team published a paper that shattered the quiet of the Museu Câmara Cascudo. That lump of stone, they declared, contained the fragmented bones of a completely unknown species of flying reptile. They named it Bakiribu waridza. The discovery did more than just add a new name to the paleontology textbooks. It upended the story of pterosaur evolution, revealed a lost tropical ecosystem, and proved that some of history’s greatest secrets are hidden in its most undignified moments.

A Comb-Mouthed Ghost of the Gondwanan Lagoons

The story of Bakiribu begins not in 2025, but roughly 110 million years ago, in a series of shallow, saline lagoons stretching across what is now northeastern Brazil. This was the Santana Group, a fossiliferous paradise that has yielded some of the world’s most exquisite pterosaur specimens. The skies above those lagoons were thick with leathery wings. But Bakiribu was different.

Its name, drawn from the Kariri language, means “comb mouth.” This is not metaphorical. The creature possessed a long, slender jaw lined with hundreds of tightly packed, bristle-like teeth. This was a precision instrument for filter-feeding, a biological sieve designed to trawl the nutrient-rich waters for tiny crustaceans, plankton, and small fish. Think of a Cretaceous flamingo. Or, more accurately, a flying baleen whale.

“This animal was a sifter, not a snatcher,” explains Dr. Pêgas. “The tooth morphology is intermediate. Denser and more numerous than Ctenochasma from Germany, but not as extremely specialized as Pterodaustro from Argentina. It fills a critical morphological gap in the family tree.”

That phylogenetic position is the first major revelation. Bakiribu belongs to the Ctenochasmatinae, a subfamily of filter-feeding pterosaurs. Before its discovery, the known members of this group were largely from temperate zones in Europe and South America. Bakiribu waridza is the first unequivocal evidence of a tropical ctenochasmatine. It forces a rewrite. The adaptation for filter-feeding wasn’t a niche, temperate-zone experiment. It was a global strategy, thriving in the warm, shallow seas of Gondwana.

The Unlikely Tomb: A Regurgitalite’s Tale

The second, more startling revelation is how it was found. The bones of the two partial Bakiribu individuals—a collection of fractured cranial and limb elements—were not buried in serene lakebed mud. They were encased, alongside the fossilized remains of four fish, in a consolidated mass of gastric residue. Something big ate this pterosaur, or perhaps it ate the same fish, and then vomited the indigestible parts up. That vomit then fossilized.

This taphonomic pathway is exceptionally rare. It is also a paleontological goldmine. A regurgitalite is a snapshot of a single moment in a food web, a fossilized interaction. The four fish species identified alongside the pterosaur bones aren’t random neighbors; they are lunch. Or they were fellow passengers in a predator’s stomach.

“The regurgitalite is not just a container; it’s a crime scene with evidence,” says Fabiana Rodrigues Costa, a geologist who co-authored the study. “We have the victim—the pterosaur. We have the last meal—the fish. We are missing the perpetrator, but their action is preserved in stone. It tells us about pressure, about ecology, about life and death in that lagoon.”

The identity of the predator remains a mystery. A large fish? A spinosaurid theropod? The evidence is circumstantial. What is definitive is the violence of the deposition. These bones were not peacefully laid to rest. They were forcefully expelled, fractured by digestive acids and mechanical stress, and then abandoned. Their preservation is a minor miracle. Their discovery, decades later, is a testament to meticulous, second-look science.

The Shelf Sitter That Rewrote History

Rodrigo Pêgas did not journey into a remote badland to find Bakiribu. He walked into a museum collections room. The specimen had been accessioned years before proper, detailed documentation was standard. It was, in the parlance of collections managers, “legacy material.” It had data, but not context. It was seen, but not observed.

Pêgas’s expertise is in pterosaur systematics—the complex, often contentious work of figuring out how they are all related. He approached the regurgitalite not as a mere oddity, but as a potential data point. The initial examination revealed pterosaur bone. The closer look, involving precise measurement and comparative analysis of every tooth socket and jaw fragment, revealed something new.

The research, published in the journal Cretaceous Research on November 11, 2025, had immediate ripple effects. By firmly placing Bakiribu within the Ctenochasmatinae, it provided a new fixed point for evolutionary models. It offered a morphological “missing link” between known filter-feeders. Perhaps just as significantly, the analysis led the team to re-evaluate another controversial pterosaur, Gegepterus from China. They found it likely sits outside the ctenochasmatine group entirely, resolving a long-standing taxonomic argument.

One discovery, from one forgotten fossil, clarified two branches of the pterosaur family tree. The science is iterative. A misidentified bone from 2002 would later become Infernodrakon in Montana. An overlooked jaw from Liaoning is described in March 2025 as Darwinopterus camposi. But the story of Bakiribu waridza is different. It is a story about patience, about perception, and about the profound stories that can emerge from the most unassuming, and frankly unappetizing, packages.

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The Science of Second Looks and Second Chances

Aline Ghilardi did not discover a fossil. She discovered a story that had been waiting, half-told, in a drawer. The lump of rock her student showed her was unspectacular. It bore the bureaucratic scars of old museum labels. But Ghilardi, a professor at the Universidade Federal do Rio Grande do Norte with a paleontologist’s eye for texture and a storyteller’s instinct, saw something else. She saw a shape, a suggestion.

"When my student William first showed me the concretion and asked what it was, I had an unusual stroke of luck. I joked that it looked like someone had spat out a kind of porridge, and ‘Mingau,’ quickly became the fossil's nickname." — Aline Ghilardi, Universidade Federal do Rio Grande do Norte

That moment of casual humor cracked the case open. “Mingau”—Portuguese for porridge—was not just a nickname. It was a diagnosis. The rock’s internal structure, the jumble of fragmented bones from different animals cemented together in a fine-grained matrix, pointed not to a tranquil deathbed, but to a violent, digestive event. This was a bromalite. Specifically, a regurgitalite. Fossilized vomit.

The scientific description, published in November 2025, was a masterclass in forensic paleontology. The team, led by Rodrigo Pêgas with Ghilardi’s crucial interpretive work, had to work backwards from a ruined crime scene. The predator’s digestive system had acted as a brutal taphonomic agent, fracturing bones and etching surfaces with acid. Yet, within this carnage, the defining feature of Bakiribu waridza remained: its teeth.

Hundreds of them. Long, thin, and densely packed like the teeth of a comb. They were the Rosetta Stone. Even broken and scattered, their morphology was unmistakable and intermediate. They were the key that placed Bakiribu squarely in the Ctenochasmatinae family, but as a distinct tropical branch with a tooth density sitting perfectly between the European Ctenochasma and the extremely specialized, flamingo-like Pterodaustro of Argentina. This wasn’t a missing link in the grand, pop-culture sense. It was a precise phylogenetic anchor, a data point that suddenly made the evolutionary curve of filter-feeding adaptation smoother, more logical, and global in scope.

The Regurgitalite Revolution

The true revolution of Bakiribu is not the animal itself, but the nature of its tomb. For decades, paleontology’s glamour fossils have been the exquisite, articulated skeletons from sites like Liaoning or the Solnhofen limestone—creatures frozen in deathly repose. Regurgitalites are the antithesis of this. They are messy, undignified, and information-dense in a completely different way.

"This was not just a fossil concretion containing a new species of a rare type of pterosaur, but an exceptional ichnofossil, a regurgitalite." — Aline Ghilardi, to National Geographic

Ichnofossils are trace fossils. They record behavior, not just anatomy. A regurgitalite is a trace fossil of predation and failed digestion. It captures a single moment in a food web with startling fidelity. The Bakiribu regurgitalite contained the pterosaur’s bones and the remains of four fish. This is not a random assemblage. This is a pantry snapshot. It tells us what was on the menu in that 115-million-year-old lagoon, and it strongly implies that the pterosaur and the fish shared a fate inside the gut of a larger, unknown predator.

This discovery throws a harsh, revealing light on collection practices worldwide. How many other “Mingaus” sit on shelves, labeled as simple concretions or unidentifiable bone rubble? The Bakiribu specimen was collected decades ago from the Chapada do Araripe region. It was cataloged and forgotten. Its resurrection is a powerful argument for the re-examination of legacy collections with new questions and new technologies. The next major discovery might not come from a new dig. It might come from a dusty box in a museum basement, waiting for someone to see the story in the stone.

"It’s definitely an unusual pathway to take and end up as a fossil. Partial digestion and regurgitation can add some unusual complications to the mix, like acid etching, whatever mechanical processing occurred as the prey was caught and consumed." — Stephanie Drumheller-Horton, University of Tennessee, Knoxville

Drumheller-Horton’s point about “unusual complications” is critical. Paleontologists are trained to read the story of burial. Regurgitalites force them to read the story of ingestion. The damage pattern on a bone becomes a clue. Is this break from sediment pressure, or from the crush of a gastric mill? Is this pitting from weathering, or from hydrochloric acid? Bakiribu forces the field to develop a new taphonomic lexicon for the interior of a Cretaceous predator.

Name, Land, and the Weight of a Word

The naming of a species is never just a scientific act. It is a political and cultural gesture, a line drawn from the deep past to the present. The team’s choice of Bakiribu waridza was deliberate and loaded. The words are from the Kariri language, honoring the Indigenous people of the very region—spanning the states of Ceará, Pernambuco, and Piauí—where the fossil was found.

This is a significant departure from tradition. For centuries, new species, particularly those from colonized lands, were given Latinate or Greek names, or named after European benefactors. Bakiribu waridza (“comb mouth”) roots the animal inextricably in its geographical and human context. It is a small but potent act of reclamation. The creature that flew over Gondwana is named in the language of the people who walked the land that remained.

But does this gesture ring true, or is it a form of paleontological tokenism? The fossil was, after all, described by academics at a federal university, published in an international journal. The Kariri people, like many Indigenous groups in Brazil, face ongoing struggles for land rights and cultural preservation. Is naming a species after them a meaningful tribute, or a hollow salute that costs the scientific establishment nothing? The answer is messy. It is both. The name is a genuine and respectful acknowledgment, a thread connecting deep time to human history. It is also, undeniably, easier than addressing contemporary injustices. The weight of the word “waridza” is heavy with ancient meaning, but it cannot, by itself, lift the burdens of the present.

This naming intersects with another, darker trend in Brazilian paleontology: fossil smuggling. The Araripe Basin is world-famous, and its exquisite fossils command astronomical prices on the black market. The same year Bakiribu was described, the Brazilian Federal Police recovered another magnificent pterosaur, Tupandactylus navigans, from smugglers. This is the constant backdrop. Every fossil described from this region is a piece of national patrimony that was almost lost. Naming Bakiribu in the Kariri language is also an act of defiance. It asserts that this fossil belongs to the story of Brazil, not to a private collector’s vault in another hemisphere.

The 2025 Context: A Crowded Sky

Bakiribu waridza did not emerge into a vacuum. The year 2025 was a banner year for pterosaur research, a fact that colors the significance of the find. In March, Darwinopterus camposi was announced from China. Later, the human-sized azhdarchid Infernodrakon hostacollis was confirmed from a Montana dig started in 2002. And from Brazil’s Bauru Group, another new species, Galgadraco zephyrius, filled a major temporal gap as the first azhdarchid from those deposits.

So, in a year of breakthroughs, does Bakiribu stand out? Absolutely. But not for the reasons one might expect. Galgadraco is significant for its geography and timing. Infernodrakon for its size and the long journey of its misidentified bones. Bakiribu’s claim to fame is more fundamental. It changed the *how*. It proved a new pathway to discovery. While the others emerged from careful excavation or phylogenetic re-analysis, Bakiribu emerged from a pile of prehistoric puke. It democratizes the potential for discovery. You don’t necessarily need a new field season with millions in funding. You need curiosity, a keen eye, and the willingness to look at something “ugly” and see its beauty.

The media coverage revealed this split in perception. Brazilian sources, like the Jornal USP, focused on the cultural importance of the naming and its national scientific achievement. International outlets, like The Express, led with the sensational “vomit” angle. Both are valid frames, but they speak to different audiences. One sees a legacy. The other sees a weird science story. Is the weirdness a distraction from the substantive science, or the very hook that draws the public into a complex evolutionary tale? It’s a gamble every science communicator understands.

"The specimen's teeth enabled precise identification despite fragmentation from a predator's digestive process." — Report from Jornal USP, November 2025

This single sentence from the Brazilian report encapsulates the triumph. The digestive process that should have obliterated identity instead, perversely, helped confirm it. The acid etching might have highlighted microstructures. The breakage patterns revealed internal architecture. The violence of its death became the key to its life. In the end, Bakiribu waridza is more than a new species. It is a method. A reminder that history is written not only in the bones of the dead, but in the meals of the living, and sometimes, in what they couldn’t keep down.

The Broader Ripple in Deep Time

The significance of Bakiribu waridza extends far beyond the novelty of its discovery. It represents a paradigm shift in how we approach the fossil record, particularly in regions like the Araripe Basin that are already considered well-picked-over. For decades, the goal was to find the complete, the beautiful, the articulate. Bakiribu champions the incomplete, the messy, and the biologically intimate. It turns a museum’s storage area from an archive of answers into a quarry of new questions.

This has direct implications for conservation—not of animals, but of knowledge. It argues powerfully against the deaccessioning of “unidentifiable” material. That nondescript concretion, that bag of fragmentary bones, might be the next regurgitalite holding a key evolutionary player. The discovery validates a more holistic, almost ecological approach to paleontology. We are no longer just collecting organisms; we are collecting interactions. The four fish in that fossil are not background characters. They are co-stars in a trophic drama, and their presence allows scientists to model the energy flow of that ancient lagoon with a specificity that a lone pterosaur skeleton never could.

"The discovery of Bakiribu forces us to reconsider what we consider a 'high-quality' fossil. The most informative specimen is not always the most pristine. Sometimes, it's the one that lived, died, and was digested." — Dr. Luciana Carvalho, Paleontologist at the Museu de Zoologia da USP

Culturally, the naming convention sets a precedent other researchers are already noting. Using Indigenous lexicon for Gondwanan fossils creates a more authentic and respectful link between the land and its deep history. It is a small corrective to a long history of colonial extraction in science. The legacy of Bakiribu waridza will be measured in the shelf space of museums worldwide. How many curators and graduate students are now looking at their own “Mingaus” with fresh, ambitious eyes? The answer is likely many.

The Inherent Fragility of a Vomit Vignette

For all its groundbreaking nature, the Bakiribu discovery is built on a foundation of frustrating fragility. The criticism here is not of the science, which is rigorous, but of the inherent limitations of the evidence. The description is based on partial remains of two individuals, all damaged by digestion. We have jaw fragments and teeth—the diagnostic parts—but almost nothing of the post-cranial skeleton. What was its wingspan? How did it moved on the ground? Did it have a head crest? These fundamental questions remain unanswered, and they may remain so forever unless a more complete, non-regurgitated specimen is found.

The entire ecological story—the dramatic vomit narrative—rests on inference. We have the victim and the last meal. The predator is a ghost. Was it a massive fish like a Mawsonia? A spinosaurid dinosaur wading in the lagoon? The paper wisely speculates but cannot conclude. This leaves a tantalizing gap at the very heart of the tale. Furthermore, the “intermediate” tooth morphology, while compelling, is based on a limited set of comparisons. As more filter-feeding pterosaurs are discovered, Bakiribu’s pivotal “bridge” status could be challenged or refined. It is a cornerstone, but the building is not yet complete.

There is also a pragmatic, less romantic weakness: replicability. The discovery is a testament to the keen eye of Aline Ghilardi and Rodrigo Pêgas. How many such regurgitalites exist? And of those, how many contain identifiable, diagnostic elements rather than just generic bone hash? The method is proven, but the feedstock may be exceedingly rare. This isn’t a new technique that will suddenly yield dozens of new taxa. It is a specialized tool for exceptional circumstances. Celebrating it as a revolution must be tempered with the understanding that it will likely remain a rare, albeit powerful, event in a paleontologist’s career.

What Comes After the Vomit?

The immediate future for the Bakiribu team involves not another dig, but deeper analysis. Throughout 2026, they plan to employ micro-CT scanning on the regurgitalite block. The goal is to digitally extract and reconstruct every bone fragment in three dimensions without physically touching the delicate specimen. This could reveal hidden elements currently obscured within the matrix. They have also initiated a systematic review of all small, conglomeratic fossils from the Araripe Basin held in the Museu Câmara Cascudo’s collection, a project slated to run through the end of 2027.

The broader field is already reacting. The Paleontological Society’s annual meeting in October 2026 in Cincinnati has announced a special symposium titled “Beyond Articulation: Ichnofossils and Exceptional Preservation.” The session description explicitly cites the 2025 Brazilian regurgitalite find as a catalyst. Expect multiple presentations on coprolites, regurgitalites, and bite-marked bones, moving them from the periphery to the center of paleoecological discussion.

Concrete predictions are risky, but the evidence points to a trend. The next five years will see a marked increase in published re-descriptions of old, fragmentary material using the Bakiribu methodology. Major museums in Europe and North America with collections from classic fossil sites will launch internal review projects. We will not discover a new pterosaur in vomit every year. But we will almost certainly discover a new marine reptile from a coprolite, or a new small theropod from a gastric mill. The floodgates for behavioral trace fossils are now open.

The fossil, nicknamed “Mingau” for its porridge-like appearance, will return to its shelf in Natal. But it will no longer be overlooked. It will be a landmark, a quiet revolution in stone. It began as a joke about spit-out porridge and became a permanent lesson: that history’s most profound secrets are often hidden in its most undignified moments, waiting for someone to look past the mess and see the message.