In the quiet cliffs of Stevns, Denmark, a 79-year-old amateur fossil hunter split open a piece of chalk last November and stumbled upon something extraordinary: a 66 million-year-old clump of fossilized vomit. This prehistoric puke, long past its gross phase, now offers a rare window into the diets and behaviors of ancient sea predators.

The fossil, classed as a “danekrae” (A designation for Danish objects of exceptional natural historical value), contains the remains of two sea lilies — delicate, stalked creatures that once carpeted the ocean floor. Scientists believe an ancient shark or large fish gulped them down during the Cretaceous period, only to regurgitate the indigestible parts shortly after.

“Sea lilies aren’t that great to eat, because they are almost only skeleton,” said Jesper Milàn, curator of Denmark’s Geomuseum Faxe. “So they took what they could and threw up the rest.”

Prehistoric Puke

Fossilized vomit is scientifically known as a regurgitalite (similarly to how a fossilized poop is known as a coprolite). This one was preserved in remarkable detail thanks to the chalky seabed that quickly buried it. This prevented scavengers from scattering the remains and allowed the clump to fossilize intact.

The tightly packed arrangement of the sea lily fragments was the key clue that this was not an ordinary fossil. “It’s not just a random accumulation of debris,” Milàn explained. “This is a concentrated mass of skeletal parts, which is typical of regurgitated material.”

The fossil dates back to the very end of the Cretaceous period, 66 million years ago. And this period ended with the catastrophic asteroid impact that wiped out the dinosaurs and a host of other species. But, it was a time of thriving marine ecosystems. Modern-day Denmark was submerged under a vast prehistoric ocean teeming with life.

A Predator’s Last Meal?

The predator that consumed these sea lilies likely lived on the ocean floor, using crushing teeth to feed on hard-shelled creatures like sea urchins and crinoids.

“There’s really not much to eat in one,” Milàn said of the sea lilies in an interview with Washington Post. “The predator probably regurgitated the hard, indigestible parts, which are also easier to be preserved as fossils.”

While the exact identity of the predator remains a mystery, scientists speculate it could have been a bottom-dwelling shark similar to the modern Port Jackson shark found in Australia.

Beyond the shock value of such an unusual finding, this ancient regurgitation may hold serious scientific value.  It provides direct evidence of predator-prey relationships and helps reconstruct ancient food chains. Similar finds, such as fossilized feces and vomit from the Jurassic and Triassic periods, have revealed insights into the diets of early dinosaurs and the ecosystems they inhabited.

This particular regurgitalite will soon go on display at Denmark’s Geomuseum Faxe, where visitors can marvel at what Milàn calls “the most famous piece of puke in the world.”