Deep Inside Fossilized Dino Vomit and Poop, Scientists Unearth a Jurassic World

Over the last quarter century, a team of paleontologists has collected and studied coprolites—fossilized poop—and dinosaur vomit, millions of years old, from what is now Poland. The team has now published its findings, revealing hitherto unknown details of the relationships between the giant reptiles and their habitats.

As the dinosaurs lived, they pooped and occasionally upchucked. In these bodily fluids (and solids) the extinct reptiles left evidence of their diet, and by proxy, their environments. The team studied the dinosaurs’ deposits using synchrotron imaging, which revealed the hidden interiors of the fossilized feces. The team discovered what the animals ate, but also painted a picture of a swath of Pangea between 230 million years ago and 200 million years ago, as the Triassic Period was giving way to the Jurassic. The team’s findings were published today in Nature.

“Our findings reveal that early dinosaur dominance was not a straightforward process but rather a complex transition influenced by factors such as ecological opportunism and competition with other animals,” said Martin Qvarnström, a researcher at Uppsala University and co-author of the study, in an email to Gizmodo. “This reshapes our understanding of how dinosaurs adapted and rose to prominence in a dynamic and competitive Triassic world.”

About 230 million years ago, Poland was part of the supercontinent Pangea. Dinosaurs, plants, fish, insects, and other living things eked out existence on its shores. There, those organisms left traces of their existence—in footprints and bite marks but also in chewed-up organic matter and crushed bones which ended up excreted or expectorated by the dinosaurs.

“25 years ago I would not have dreamed that I would travel with kilograms of fossilized dinosaur feces to the synchrotron in Grenoble, and use this advanced instrument to study the Triassic and Jurassic dinosaurs of Poland,” said Grzegorz Niedźwiedzki, a researcher at Uppsala University and lead author of the study, in an email to Gizmodo. “We were as happy as children opening Christmas presents at every find of a coprolite.”

A synchrotron image of fish scales in a dinosaur coprolite. Image: Martin Qvarnström

The team took hundreds of coprolite samples to a synchrotron to visualize their internal bits—specifically seeking undigested food. The coprolites of large herbivores—sauropods, to be exact—surprised the team. The coprolites contained ferns and other plants, but also charcoal. The team posited that the animals may have consumed charcoal to protect themselves from toxins that may have been present in the ferns.

“Firstly, we could see for the first time what these early dinosaurs ate, secondly, what they ate from the plants that grew in the Triassic and Jurassic ecosystems, and thirdly, what is even more interesting, among these plant remains found in the coprolite mass were many whose fossils do not occur in the sites where we found the coprolites,” Niedźwiedzki added. “The dinosaurs probably fed in a different place than the one where we discovered their fossilized feces.”

The team believes that more information may still be hidden in the coprolites; thankfully, synchrotron imaging is non-invasive, so the researchers can go back for seconds. Besides revisiting the coprolites, there is a site from the early Jurassic that Niedźwiedzki said was “a real treasure trove.”

“To this day we have excavated several thousand dinosaur tracks there,” he said. “We have something to do for the next 25 years.”

The dinosaurs were wiped from the face of the Earth 66 million years ago, when an asteroid—and perhaps two—smashed into the planet’s surface, kicking up a mega tsunami and dust, soot, and sulfur that blotted out the Sun. But the dinosaurs’ demise happened about 150 million years after the moments in deep time captured in the recently interrogated coprolites.

In other words, there are still millions of years of history that may be locked away in yet-to-be-excavated dinosaur poop and hurl. It’ll take patience, luck, and a bit of time with the synchrotron, but we may yet learn more about the days of the dinosaurs through their rejectamenta.