Staring at a pile of fossilised ichthyosaur bones in the famous Berlin-Ichthyosaur State Park in Nevada, paleontologist Mark McMenamin had a sudden insight. It occurred to him that he might have cracked the great mystery of this ancient Triassic site.
He reckoned that the carefully lined-up bones of the ichthyosaurs, of the shonisaur family, were the work of a kraken, an enormous squid bigger and more intelligent than any other invertebrate that has ever lived. That's what the professor at Mount Holyoke College told the Geological Society of America, anyway, speaking this week at their annual get together.
How nine of these sperm-whale-sized ichthyosaurs ended up lying back to back in a little pile has puzzled paleontologists since the site was discovered in 1926. Did toxic algae really bump off these giant predators all at once right next to each other?
Another theory that the sea predators were cruising in shallow water and had been beached were disproved by surveys of surrounding material, which suggested they had died and been buried in the deep sea. But could any megapredator have taken down these huge toothy carnivores?
McMenamin saw the answer in this National Geographic video - Shark versus Octopus. In it a small octopus takes down a dogshark in an ambush lasting less than two minutes. He hypothesises that the same thing could have happened in the Triassic era, on a larger scale. He imagines the Triassic kraken to be a horrifying 30m long, twice as large as today's colossal squid.
In a slightly trippy abstract to the paper McMenamin has authored on the topic, the professor explains how the unusual bone arrangements in the archaeological site led to his kraken theory:
"The proposed Triassic kraken, which could have been the most intelligent invertebrate ever, arranged the vertebral discs in biserial patterns, with individual pieces nesting in a fitted fashion as if they were part of a puzzle. The arranged vertebrae resemble the pattern of sucker discs on a cephalopod tentacle, with each amphicoelous vertebra strongly resembling a coleoid sucker. Thus the tessellated vertebral disc pavement may represent the earliest known self‑portrait."
No one at El Reg has ever heard of an octopus making a self-portrait, but some of us appreciate its desire to keep things nice and tidy.
Among the evidences of the kraken attacks are many more ribs broken in the shonisaur fossils than would seem accidental and the twisted necks of the ichthyosaurs. "It was either drowning them or breaking their necks," he said.
The soft-bodied octopus didn't survive fossilisation, so there is no chance of a final proof emerging but perhaps we can see its sucker touch in the layout of the bones.
Triassic Kraken: The Berlin Icthyosaur Death Assemblage Interpreted As A Giant Cephalopod Midden, as presented to the Geological Society of America, is right here. ®