We’ve talked yesterday about how behavior doesn’t fossilize, and that is true — most of the time. Some extremely rare finds, such as this fossil discovered in the 19th century, can be the exception to that rule.
Despite its age, the fossil wasn’t analyzed properly until now.
Image credits Malcolm Hart / Proceedings of the Geologists’ Association.
It was discovered in Jurrasic-aged rocks off the coast of England and captured the oldest known case of a squid-like creature attacking prey. The event took place almost 200 million years old and the fossil is currently housed within the collections of the British Geological Survey in Nottingham.
Fish for dinner
“Since the 19th century, the Blue Lias and Charmouth Mudstone formations of the Dorset coast have provided large numbers of important body fossils that inform our knowledge of coleoid paleontology,” says Professor Malcolm Hart, Emeritus Professor in Plymouth and the lead author of a study analyzing the fossil.
“This, however, is a most unusual if not extraordinary fossil as predation events are only very occasionally found in the geological record. It points to a particularly violent attack which ultimately appears to have caused the death, and subsequent preservation, of both animals.”
The team identified the attacker as a Clarkeiteuthis montefiorei with its prey belonging to the herring-like species Dorsetichthys bechei.
The particular position of the attacker’s arms suggests that what we’re seeing is an actual predatory event, and not a quirk of fossilization, according to the team. They believe this specimen hails from the Sinemurian period, between 190 and 199 million years ago, which would make it the oldest fossil of its kind by about 10 million years.
The attack doesn’t seem to have been a pleasurable experience for the fish at all: the team explains that the bones in its head were apparently crushed by the squid.
Image credits Malcolm Hart / Proceedings of the Geologists’ Association
The authors believed that the attacker, too, bit off more than it could chew. The fish was likely too large for it to successfully bring down, or got stuck in its jaws. The unfortunate pair eventually killed each other by the looks of it, and found their way to the bottom of the ocean where they fossilized.
Another possible explanation is that the Clarkeiteuthis brought its prey down below in a display of ‘distraction sinking’, behavior meant to discourage other predators from attacking, or possibly just to hide from them. It’s possible that the squid swam into a body of low-oxygen water, where it suffocated.
The findings have been presented at the virtual event EGU2020: Sharing Geoscience Online this week in the “Life and Death in the Jurassic Seas of Dorset, Southern England” session. They will also be published in the journal Proceedings of the Geologists’ Association.