Researchers analyzed more than 300 Aspidorhynchus fossils from Late Jurassic German deposits and identified 10 heads preserved with digestive tracts still attached. Stomach contents indicate Aspidorhynchus fed on small teleosts and occasionally larger prey such as a 6-inch Allothrissops. The pattern of decapitation is consistent with attacks by large "grabber" marine reptiles (e.g., ichthyosaurs and pliosaurs), providing rare, direct evidence of violent predator–prey interactions in ancient seas.
Gory Jurassic Fossils Reveal Violent Decapitations by Giant Marine Reptiles
Researchers analyzed more than 300 Aspidorhynchus fossils from Late Jurassic German deposits and identified 10 heads preserved with digestive tracts still attached. Stomach contents indicate Aspidorhynchus fed on small teleosts and occasionally larger prey such as a 6-inch Allothrissops. The pattern of decapitation is consistent with attacks by large "grabber" marine reptiles (e.g., ichthyosaurs and pliosaurs), providing rare, direct evidence of violent predator–prey interactions in ancient seas.
07:24 AM, 11/20/2025Science
More than 100 million years ago, shallow seas that once covered parts of what is now Germany were the scene of brutal predator–prey encounters, according to a new analysis of exceptionally preserved fossils.
Researchers examined over 300 specimens of Aspidorhynchus, an extinct genus of long-jawed, swordfish-like fish, from Late Jurassic deposits dating roughly 160–145 million years ago. Among the material were 10 detached Aspidorhynchus heads found with portions of digestive tracts still attached — a rare preservation of soft tissues that provides an unusually clear snapshot of ancient behavior.
Aspidorhynchus reached about 3 feet (roughly 1 meter) in length and had an elongated, blade-like upper jaw reminiscent of modern swordfish. Stomach contents in the preserved guts show these fish swallowed small teleosts whole and head-first, and in at least one case ingested a larger prey item: an Allothrissops about 6 inches long. These findings suggest Aspidorhynchus hunted in ways comparable to some modern billfishes, slashing or lunging into schools of smaller fish.
The decapitated heads give a grisly clue to how some individuals met their end. The authors of the study published in Fossil Record propose that powerful "grabber" predators — large marine reptiles that seized prey tail-first — dispatched victims with violent headshakes and repeated bites. Such attacks could sever the head, sometimes with gut contents still attached when the remains sank to the seafloor.
"These are extraordinary fossils — unique in the fossil record," the authors note, highlighting the rarity and clarity of the preserved interactions.
Marine biologist David Bellwood, quoted in the study, explained that if a predator "cut the head at the dorsal connection with the spine then pull the head off," the guts could come away with it. Aspidorhynchus vertebrae may have been relatively soft at that joint, making decapitation easier for large predators such as ichthyosaurs and pliosaurs, some of which exceeded 13 feet in length.
Because these specimens capture both predator damage and stomach contents, they offer a unique window into Late Jurassic marine food webs and the violent interactions that shaped them.