The word fossil might conjure the bones of a creature itself—a towering T.

“It’s kind of rare to find direct evidence of who is eating who, or who is vomiting up who, in the fossil record,” said Brian Engh, a paleoartist and filmmaker.

But Foster and colleagues were focused on a lesser-known swath of the Morrison whose abundance of fossilized plants gave it the nickname the “Salad Bar.” “There’s a lot to be found in this formation still, and some of it is going to be barf,” Engh said.

The researchers brought the specimen back to the museum, where it sat for a year among an assortment of mysteries—”things that we just can’t tell what they are,” Foster said.

With a microscope, Foster realized what he was looking at was not a plant at all, but a jumble of amphibian bones, some of which were just three millimeters long.

At first, he said, he planned simply to illustrate a fish barfing.

And also that won’t show what the fish was eating.” To preemptively answer that question, Engh tried another sketch of a fish being chomped by a crocodilian and barfing defensively—a way of distracting the predator.

The final illustration was inspired by the Jaws poster: a bowfin fish approaching the oblivious frog from underneath, ready to chomp.

“I realized that I still wanted to show the barfing, so I added another bowfin barfing in the background,” Engh said.

When Engh’s wife, an evolutionary biologist who studies fish, mentioned that lungfish chew by encapsulating whatever they’re eating in a glob of mucus and slurp it all in, Engh added a viscous coating of mucus to his regurgitated frog.

It’s possible the predator may have barfed up the swallowed frogs defensively or after digesting frog meat in an attempt to purge the frog bones, Foster said.

“Some of it would have been very familiar to us.” If we had been sitting on the shores of this Jurassic pond, we probably would have heard a chorus of frogs, Foster said, and maybe even the distinct, timeless sound of a carnivore upchucking a frog that would chorus no more