The Last Meal of Portheus

The Last Meal of Portheus

In the museum of Fort Hays State University, Hays, Kansas, a most unusual fossil is on display. It is that of a large tarponlike fish, Portheus molossus. Within the fourteen—foot skeleton is that of another fossil;, the six—foot remains of another tarpon, Gillicus sp., which had evidently been swallowed whole.

The sequence of events was easily established by the investigative research team. Portheus, a vicious predator of the Mesozoic seas, was out looking for prey. Spotting the potential victim, it darted down and quickly swallowed its prey alive. As the saying goes, "It had bitten off more than it could chew," because the victim, the six—foot Gillicus, did not die readily. Instead it sold its life dearly be intensely thrashing about inside the predator's stomach. The swallowed victim, being as large as it was, inflicted much damage.

Portheus, after swallowing its prey, swam off contentedly, its hunger thoroughly appeased by Gillicus. It soon became aware that an excruciating stomachache was developing, and the pain worsened quickly. The internal thrashing of the Gillicus must have ripped the stomach apart along with other internal organs. Portheus dies promptly and sank slowly to the sea bottom, a victim of its own prey. Ironically the swallowed fish, as if in momentary retribution, lived on after its assassin died. Since there was no way it could get out of the body of Portheus, it too died shortly afterward. The body of the large tarpon, along with its fatal dinner, settled into the soft bottom muds of the sea, where they were buried and preserved by natural processes. In time the skeletons were fossilized as the encasing muds were turned into rock.

With the passage of time and the ancient sea long gone, the forces of erosion eventually laid bare the rock, exposing the skeletons of Portheus and its last meal. The revealed fossils represent a rather dramatic bit of evidence of an event that happened well over one hundred million years in an inland sea that covered the area that is now the state of Kansas.

From the book: 
Our Fascinating Earth