This ammonite was fossilized outside its shell

If curious humans have nightmares of being naked in public, a curious ammonite may have dreamed of swimming without its shell, its soft body exposed to the elements and the eyes of predators.

For an unfortunate Ammonite in the late Jurassic, it was no dream but a harsh reality. This animal was completely killed, outside its shell, and was thus buried. According to a recently published study in the Swiss Journal of Palaeontology, Ammonite’s death made it an extraordinary fossil – one of the very few records of soft tissue in a creature that is most often immortalized as a shell..

“We know the millions and millions of Ammonites that have been protected by their shell, so something extraordinary had to happen here,” said Thomas Clements, a paleontologist at the University of Birmingham in England who was not involved with the research. “It’s like finding – said Dr. Clements, following.” Well, I don’t even know what it’s like, it’s bizarre. “

René Hoffmann, an ammonitologist at the Ruhr-University Bochum in Germany, who reviewed the study, called the fossil a “paleontological jackpot that only occurs once in a lifetime.”

To the untrained eye, the fossil looks more like an impressionist painting than an Ammonite: a pink, bean-shaped smear surrounded by protrusions, veins, and ovals. It was discovered in the Sollenhofen-Extet region of southern Germany, an island archipelago bordered by an oxygen-deprived lagoon, about 150 million years ago, in the Ammonites’ day. These conditions allowed soft, dead creatures to be drowned in mud by predators or bacteria, according to Christian Klug, a paleontologist at the University of Zurich, Switzerland, and the paper’s first author.

When dr. When Klug first saw the fossil, he knew that it represented the soft parts of an Ammonite, but did not know exactly which soft parts are. He left it alone for months until Helmut Tischlinger, a fossil collector and a writer on paper, sent him photographs of the fossil with ultraviolet light, which revealed minute height and mineral stains in the fossil.

Dr. Klugh reconstructs the anatomy of the creature progressively, from the most visible organs to the most obscure. They first identified Epithicus, a lower lower jaw indicating that the fossil was an ammonite. At the back of the jaw, they found the chitinous layer of the esophagus, and then a lump that suggested a digestive system with a colite – the fecal substance (they used a different word) “which is still in the intestine,” Dr. Klug clarified.

“For the most part, gentle body reconstruction is in the true sense,” said Margaret Yakobuchi, a paleontologist at Bowling Green State University in Ohio, who was not involved with the research.

Unraveling the other mystery of the fossil – how the Ammonites were to be separated from their shells – was much more difficult. The soft parts were so intact that they still looked coiled. The authors propose several alternative endings to Ammoni’s life, each possible but uncertain. One says that the soft parts of the dead ammonite slipped away when the tissue connecting his conch to the shell began to rot.

Another, more detailed description imagines a hunter breaking the Ammonite’s shell from behind and sucking his body to leave only the naked Ammonites. “The best explanation is that some squid-like creature took out the soft parts and could not retrieve it,” Dr. Klug said.

Dr. Clements finds the clumsy hunter hunter theory “terrible” if it is unlikely; Probably more visible damage will be seen on the bird’s body at once. But he has no good choice. The interpretation of a fossil always invites some degree of skepticism, and Drs. Clements predicts that unarmed ammonite will be re-analyzed with strong chemical analysis in the future.

Curiously, the fossil Ammonite is missing his arms, unraveling one of the outstanding mysteries of Ammonite Anatomy. “Do they have many thin, delicate arms like modern kites, such as modern nautilus or some strong arms?” Dr. Yakubuchi asked. “If I had access to the time machine, the first thing I would do was return to Jurassic to see what the weapons were like.”

If a squid-like predator does indeed release ammonite from its shell, it can melt an unknown amount of the organism as a consolation prize, both nurturing ancient cephalopods and scientists studying them.

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