290 Million Years of Heartburn: What the World’s Oldest Land-Based Vomit Reveals About Life Before Dinosaurs

 

1. The Hook: A Uniquely Productive Rejection

We usually think of fossils as pristine skeletons or stately footprints, but sometimes the most "disgusting" remnants are the most scientifically revealing. Take, for instance, a walnut-to-lime-sized lump of 290-million-year-old vomit found at the Bromacker site in Thuringia, Germany. Long before the first dinosaur walked the Earth, an apex predator in a Permian mountain valley snapped up its prey and, sometime later, coughed up the remains. This uniquely productive rejection has become a "window into the past," transforming a messy moment of prehistoric heartburn into a high-fidelity record of ancient life. While skeletons show us how an animal died, this fossil—a compact cluster of bones and digestive material—shows us exactly how it, and its neighbors, lived on a single afternoon nearly 300 million years ago.

2. The Discovery of the World's Oldest "Regurgitalite"

In the world of paleontology, fossilized vomit is known as a "regurgitalite." These specimens are exceptionally rare in land-based ecosystems because they require immediate burial; otherwise, the sun, scavengers, or rain would scatter the fragile, sticky mass. While marine regurgitalites are more common, the specimen found at Bromacker is the oldest of its kind ever recovered from an inland environment. It offers a rare glimpse into the Permian period, a time when sophisticated predators first began to dominate terrestrial landscapes.

“It's kind of like a photograph of a moment in the past that is telling us about the animal that was living. Any data that we can find about their behavior is very precious.” — Arnaud Rebillard, paleontologist at Museum für Naturkunde in Berlin.

3. Takeaway 1: A Fossilized Snapshot of an Ancient Food Web

Finding scattered skeletons across a dig site suggests species lived in the same general era, but this fossilized mass provides definitive proof of a specific biological interaction. Because this single meal contained 41 bone fragments from three distinct species, researchers can confirm these animals occupied the same space at the same time—likely down to the very hour. The fact that the bones are clustered together, with long bones aligned in a way that suggests they were expelled as a single unitary "pellet," proves this wasn't a random collection of debris washed together by a stream. It was a single, opportunistic feeding event.

The prey identified within the regurgitalite included:

• Thuringothyris mahlendorffae: A small reptile, measuring approximately 3.5 inches.
• Eudibamus cursoris: A lizard-like reptile, approximately 4 inches in length.
• A juvenile diadectid: A relative of the large herbivore Diadectes, which as an adult could reach lengths of 2 feet.

4. Takeaway 2: Our Ancient Relatives Were the Apex Predators

The "eater" in this prehistoric drama was likely one of two dominant carnivores found at Bromacker: Dimetrodon teutonis (the famous sail-backed predator) or the formidable Tambacarnifex unguifalcatus. It is a common misconception that these were dinosaurs; they were actually synapsids. This is a critical distinction, as synapsids are the evolutionary lineage that eventually produced mammals. These were our own distant relatives, acting as the world's first terrestrial apex predators.

The variety of bones found in the mass—ranging from tiny reptiles to larger herbivores—reveals that these ancient synapsids were highly opportunistic generalists. Rather than specializing in one type of food, they snapped up whatever moved, effectively anchoring the top of the Permian food web.

5. Takeaway 3: The High-Tech "CSI" of Paleontology

To study the delicate mass without destroying it, researchers used micro-CT scanning. This technology uses high-resolution X-rays to create 3D digital models, allowing scientists to "see" and rotate the 41 bones inside the sandstone without cracking the specimen. This non-destructive "CSI" approach revealed the internal alignment of the bones, confirming they were expelled as a compact unit.

Chemical analysis was also vital to distinguish this "gastroregurgitalite" (vomit from the stomach) from a "coprolite" (fossilized poop). Unlike the famous "owl pellets" produced by birds—known as ornithoregurgitalites—this find predates them by hundreds of millions of years.

• Phosphorus Levels: Coprolites typically have a high phosphorus concentration because the material stays in the digestive tract long enough to be processed into a phosphatic matrix. In contrast, the Bromacker specimen was surrounded by sediment with low phosphorus levels, matching the local floodplain mud.
• Gastric Etching: The bones showed minimal "gastric etching"—damage from stomach acids—indicating the meal was regurgitated quickly before the digestion process could break down the skeletal structures.

6. Takeaway 4: 2026 is the Year of Evolutionary Insight

The Bromacker discovery is a centerpiece of a historic year for paleontology. In 2026, several massive breakthroughs have reshaped our understanding of prehistoric life:

1. Jurassic Termite Fungal Farming: Analysis of the ichnofossil Eopolis ekdalei from the Morrison Formation provided the first evidence that termites were practicing sophisticated fungal farming as far back as the Late Jurassic.
2. The "Super-Progenitor" Species Model: Researcher Parins-Fukuchi introduced a new birth-death-sampling model proposing the existence of long-lived ancestral "super-progenitors." This model provides a revolutionary way to track how biodiversity spreads through the fossil record in groups with high levels of preservation.

7. Conclusion: Lessons from the Bromacker Sandstone

The ongoing BROMACKER project—a collaboration between the Museum für Naturkunde Berlin, the University of Jena, and the UNESCO Global Geopark Thuringia—aims to establish this site as a permanent hub for cutting-edge research and science communication. By combining 3D digital modeling with traditional fieldwork, the project demonstrates that even a "mundane" lump of vomit can answer massive questions about how the first terrestrial ecosystems functioned.

As we peel back the layers of the Bromacker sandstone, we have to wonder: what other small, messy moments of prehistoric life—a single footprint, a fossilized burrow, or a coughed-up meal—are still waiting to be discovered right beneath our feet?