In a groundbreaking discovery, two paleontologists from Universität Hohenheim's Staatliches Museum für Naturkunde Stuttgart have unearthed a remarkable fossil from the Jurassic era. The fossilized fish, known as Pachycormus macropterus, was found in Germany's Posidonienschiefer Formation, dating back approximately 174 to 182 million years ago.
This ancient fish belonged to the actinopterygian group, which are bony, ray-finned fish—similar to modern-day lionfish. Upon examination, the researchers made a fascinating revelation: the fish's belly was filled with a diverse range of prey, including soft-bodied mollusks resembling modern cuttlefish or squid, as well as smaller fish.
However, the most intriguing find was a large ammonite conch, measuring about 10 centimeters across. Strikingly, the ammonite showed no signs of digestion, suggesting that the fish died shortly after swallowing it. The researchers postulate that the ammonite was too large for the fish to digest properly. They propose two possible scenarios: the fish might have mistaken the ammonite for something else, or it became lodged in its mouth for an unknown reason. Unable to expel the obstruction, the fish had no option but to consume it, inadvertently sealing its fate.
The unfortunate event led to the fish's demise, causing it to sink to the ocean floor and become buried in mud over time. The excellent preservation of the ammonite's condition attests to this unique find. This discovery marks the first recorded instance of a fatal last meal in an extinct pachycormid fish. Moreover, it hints at the possibility that bony fish in the Jurassic era might have consumed ammonites more frequently than previously assumed. This ancient fossil provides valuable insight into the distant past and offers tantalizing clues about prehistoric marine ecosystems.