200-Million-Year-Old Fossil Captures Squid Viciously Entangled With Its Prey

The specimen may be the earliest known example of a squid-like creature on the attack

Fossil of squid-relative attacking a fish
The full fossil with the body of the squid on the left and the fish to the right. Hart et al., Proceedings of the Geologists' Association

Paleontologists have discovered a vicious undersea attack frozen in stone for nearly 200 million years. In the fossil’s hardened sediments, an ancient squid-like creature called Clarkeiteuthis montefiorei has its prey wrapped up in tentacles studded with hooks, according to a statement from the University of Plymouth. The skull of the herring-like fish Dorsetichthys bechei appears to have been violently crushed, perhaps by the cephalopod’s beak.

Researchers aren’t sure how the deadly drama came to be preserved just before its denouement, but the find may be the earliest known example of a squid-like predator attacking its prey.

“The predation is off-the-scale in terms of rare occurrence,” Malcom Hart, a paleontologist emeritus at the University of Plymouth who led the research, tells George Dvorsky of Gizmodo. “There are only a very few specimens—between five to 10—known from the Jurassic, and this is the only one from this stratigraphical level in Dorset. It is also the oldest known in any part of the world.”

Fossil of squid-relative attacking a fish
The full fossil with the body of the squid on the left and the fish to the right. Hart et al., Proceedings of the Geologists' Association

The 23-inch fossil at the center of the new analysis, which has been accepted for publication in the journal Proceedings of the Geologists' Association, was first unearthed in the 19th century from the Jurassic coast (also known as the Dorset coast) of southern England. Following its discovery, the specimen was housed in the collections of the British Geological Survey.

"I was going through some new material in a private collection, and was told that this specimen was on loan to Lyme Regis Museum," Hart tells Rosie McCall of Newsweek. "I recognized it immediately for what was there—the ink sack of the squid—and the fish being held by the arms of the squid. The previous week I had been looking at a paper that mentioned the 'oldest' known example of such predation—and here I was looking at something a few millions of years older."

The researchers say this fossil dates back to the Sinemurian period, roughly 190 million years ago, predating what was thought to be the oldest example of such an interaction by some 10 million years, according to the paper.

The researchers offer two possible explanations for how this prehistoric pair came to be preserved in a tentacled embrace.

The first is that the Clarkeiteuthis, an extinct type of internal-shelled cephalopod called a belemnoid, bit off more than it could chew. In this scenario, the fish was so large that it became stuck in the jaws of the Clarkeiteuthis, which then sank to the seafloor under the weight of a dinner it could not eat and was preserved in the mud.

The second theory is that the squid intentionally sank itself and its prey to the bottom to avoid being eaten itself while feeding—a behavior observed in living squid called “distraction sinking.” The researchers hypothesize that as the animals sank they entered water that was so low in oxygen they suffocated and were eventually preserved on the bottom.

Hart tells Gizmodo that it’s surprising that these dead combatants didn’t wind up eaten by something else before being encased in sediment.

"Fossils that show the interaction between predators and prey are very rare— but other examples of this exact species of belemnoid having captured fish during the last moments of their life are known and written about in the literature," Thomas Clements, a paleontologist at the University of Birmingham who was not involved in the research, tells Newsweek. However, he adds, “the fossil does show that potentially, some belemnoid cephalopods had eyes too big for their belly!"

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