The ichthyosaur graveyard
In the Shoshone Mountains of central Nevada, Berlin-Ichthyosaur State Park protects a unique and perplexing fossil assemblage. During the Late Triassic period, about 225 million years ago, this region was a deep sea basin. The remains of at least 37 massive marine reptiles, Shonisaurus popularis, are preserved here. These were enormous creatures, reaching lengths of up to 50 feet (15 meters).
The mystery of the site is not the presence of the fossils, but their arrangement. The bones of nine individuals lie together, yet the pattern does not suggest a simple mass stranding event. Some of the vertebral columns are organized into unusual, double-line patterns. This strange configuration has puzzled paleontologists for decades, leading to one of the most controversial hypotheses in the field.
An artist of the deep
In 2011, paleontologist Mark McMenamin proposed a radical explanation for the ordered bones. He argued that the ichthyosaurs were hunted and killed by a colossal, undiscovered species of cephalopod—a Triassic kraken. McMenamin posited that this creature could have reached a length of 30 meters (nearly 100 feet). According to his hypothesis, this intelligent predator dragged its prey to its lair on the sea floor and manipulated the bones.
The most striking part of the claim is that the double rows of vertebral discs were intentionally arranged by the kraken to resemble the sucker patterns on its own tentacles, a form of primitive self-portrait. McMenamin draws a parallel with modern octopuses, which are known to collect and arrange objects like shells near their dens. While no fossil of the kraken's soft body has been found. McMenamin later presented a fossil fragment he identified as a large cephalopod beak as potential evidence.
A skeptical consensus
The scientific community has met the Triassic Kraken hypothesis with considerable skepticism. Most paleontologists argue that the bone patterns can be explained by natural, unthinking processes. The principle of parsimony, or Occam's razor, suggests that the simplest explanation is usually the correct one, and a bone-arranging monster is not the simplest explanation.
Alternative theories propose that after the ichthyosaurs died and sank to the seafloor, their carcasses decomposed. As ligaments rotted away, the vertebral columns would have fallen apart. Gentle underwater currents or sediment shifts over millions of years could have been enough to nudge the discus-shaped vertebrae into the observed linear patterns. A similar biserial arrangement of ichthyosaur vertebrae has been found in Switzerland, suggesting a taphonomic effect rather than a singular, creative predator. More recent research from 2022 suggests the Nevada site may have been an ancient birthing ground for Shonisaurus, where adults, newborns, and embryos died over hundreds of thousands of years.