At Berlin-Ichthyosaur State Park in Nevada is a site where the remains of nine 45-foot (14-meter) ichthyosaurs, of the species Shonisaurus popularis can be found. These were the Triassic’s counterpart to today’s predatory giant squid-eating sperm whales. The new thinking is that there was a Kraken (giant octopus) that preyed on the ichthyosaurs.
They hypothesize that the shonisaurs were killed and carried to the site by an enormous Triassic cephalopod, a “kraken,” with estimated length of approximately 30 meters, twice that of the modern Colossal Squid Mesonychoteuthis. 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. The submarine contest between cephalopods and seagoing tetrapods has a long history. A Triassic kraken would have posed a deadly risk for shonisaurs as they dove in pursuit of their smaller cephalopod prey.
It was a very odd configuration of bones. First of all, the different degrees of etching on the bones suggested that the shonisaurs were not all killed and buried at the same time. It also looked like the bones had been purposefully rearranged. That it got him thinking about a particular modern predator that is known for just this sort of intelligent manipulation of bones.
“Modern octopus will do this,” McMenamin said. What if there was an ancient, very large sort of octopus, like the kraken of mythology. “I think that these things were captured by the kraken and taken to the midden and the cephalopod would take them apart.”
The arranged vertebrae resemble the pattern of sucker discs on a cephalopod tentacle, with each vertebra strongly resembling a coleoid sucker. In other words, the vertebral disc “pavement” seen at the state park may represent the earliest known self portrait.
But could an octopus really have taken out such huge swimming predatory reptiles? No one would have believed such a tale until the staff of the Seattle Aquarium set up a video camera at night a few years ago to find out what was killing the sharks in one of their large tanks. What they were shocked to discover was that a large octopus they had in the same tank was the culprit. The video of one of these attacks is available on the web to anyone who uses the search terms “shark vs octopus.”
“We think that this cephalopod in the Triassic was doing the same thing,” said McMenamin. 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.”