A dramatic scene of predator capturing prey has been captured and preserved for 200 million years, shedding light on the creatures that once roamed our planet and swam in its dark ocean depths.
A new analysis of two fossilized specimens discovered on the Jurassic Coast of southern England back in the 19th-century appears to be the oldest known example of a squid-like predator attacking its prey, according to new research presented today at the Sharing Geoscience Online virtual gathering of the annual European Geosciences Union meeting. As its name suggests, the Jurassic Coast is known for its abundance of fossils dating back to the Triassic, Jurassic, and Cretaceous Periods, three geological periods that make up the Mesozoic Era spanning between 65 and 250 million years ago. The unique geology of this coastline offers a “complete record” of the profound changes that occurred across our planet over millions of years. Its rich history awarded the coast a designation as a UNESCO World Heritage Site in 2001.
Researchers with the University of Plymouth, in conjunction with the University of Kansas and Dorset-based company The Forge Fossils analyzed the specimen, which is currently housed within the collections of the British Geological Survey in Nottingham. The now-identified squid-like creature known as a Clarkeiteuthis montefiorei was preserved in perpetuity with a small, herring-like fish known as Dorsetichthys bechei trapped within its jaws. The researchers estimate that the fated duo date back to the Sinemurian period – between 190 and 199 million years ago – predating any similar samples by more than 10 million years. Their findings are due to be published in the Proceedings of the Geologists' Association.
"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. In many of these mudstones, specimens of palaeobiological significance have been found, especially those with the arms and hooks with which the living animals caught their prey,” said study lead author Malcolm Hart, emeritus professor at Plymouth, in a statement.
"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."
In what is described as a brutal incident, the head bones of the small fish appear to be completely crushed by its squid-like attacker. The position of the predator’s arms wrapped alongside the body of the fish suggest that the sediment captured the hunt shortly after it happened. But how did this come to be? The researchers propose two theories.
First, it is possible that the eyes of C. montefiorei were much too big for its stomach – er, mouth. The smaller prey may have become stuck in its capturer’s mouth, killing the larger creature before settling to the seafloor where they became preserved in sediments. Or, it could be that the attacker took its prey to the seafloor in a method that is known as “distraction sinking” a method of hunting that has been recorded at other fossil sites whereby the predator pretends to sink so to avoid being attacked by another hungrier, larger predator. Unfortunately for C. montefiorei, the strategy ended poorly. If this was how the scenario played out, the squid-like creature likely suffocated during its descent into oxygen-poor waters.