Scientists have discovered that a fish from the dinosaur era appears to have died due to getting eyes too big for its stomach and then ingesting an enormous shell. As they said, the fish could have swallowed it to death, or the bullet ripped its belly while it ate the food.

Researchers in Germany discovered the fish to have ammonite’s shell, an extinct species of marine mollusks trapped inside it. This is the first occasion fossilized fish have been found with an intact large ammonite in the body of the fish, Samuel Cooper, a  doctoral student of the State Museum of Natural History Stuttgart in Germany, said on Live Science.

The fossil was discovered close to Stuttgart in 1977. It was placed in a museum drawer until scientists recently examined it more closely and figured out how the prehistoric fish died.

“If you want to make a really exciting discovery in paleontology, you don’t always need to visit the quarry or a cliff or even go fossil hunting,” Cooper explained. “All you’ve got to do is just go to your local museum and ask to open some drawers.” Cooper and his colleague wrote a report on the fossil in July

At around 180 million in the Jurassic (201 million to 145 million years in the past), southwest Germany was covered by the warm, shallow waters that housed giant marine animals like ichthyosaurs and Plesiosaurs.

In the shadows of those vast creatures was a variety of marine animals smaller in size, such as the Pachycormus macropterus — a slim tuna-like fish measuring 3 feet (0.9 meters) long. Cooper explained that the Paleontologists believe that the Pachycormus fish consumed soft food like squids. However, one day, a fish decided to shake the way things were done.

It reveals the footprint of a four-inch-wide (10 centimeters) spiral ammonite shell pushed against the fish’s spine. For an animal of this size, it’s probably far too large to swallow.

“I suppose it’s equivalent of you and I swallowing a small dinner plate,” Cooper stated. Cooper believes the fish might mistaken the shell for an edible piece of food or accidentally swallowed it as it ate.

Researchers had previously known that the museum had the fossilized remains of a fish and ammonite. But they believed this pair could be a coincidence, Cooper stated. It could be that, for instance, the ammonite and the fish were buried in the exact location and fossilized in the same spot.

However, by examining this specimen, Cooper observed that certain parts of the fish were located on the top of the fossilized ammonite, and the rest were beneath it, indicating how the ammonite shell was within the fish when it passed away.

Additionally, some of the aragonite mineral that forms a large portion of the ammonite shell is exceptionally well-preserved. Cooper said that Aragonite is known to degrade in fossils and is extremely difficult to find. However, in this instance, the fish’s stomach could provide a barrier for the shell that prevents completely degrading Aragonite.

In putting the pieces together and learning the details of how these creatures who had been dead for a long time lived and died, scientists can begin to restore this marine ecosystem from the Jurassic period back to its former glory.

“For me,” Cooper stated, “it just paints a really interesting picture of what was actually going on.”