Scientists discover 'chunkiest' Jurassic squid species in Wyoming fossils

In the late 1990s, a paleontologist named Burkhard Pohl was working through Wyoming's fossil-bearing rocks when he spotted something that stopped him cold: a belemnite—the fossilized remains of an ancient squid-like creature—that was far thicker and rounder than anything he had encountered before. He collected it, brought it back to the Wyoming Dinosaur Center, and placed it in a drawer. For nearly three decades, it sat there, unstudied, waiting for a reason to matter.

Belemnites are among the most abundant fossils on Earth. Millions of them have been pulled from Wyoming's Sundance Formation, the remnants of an ancient inland sea that once covered the western United States. They are recognized by their bullet-shaped remains, called rostra or guards—compact, streamlined objects typically measuring five to ten centimeters long and only one to two centimeters wide. Local paleontologists have a nickname for them: squid butts. They are common enough that most researchers pass them by without a second glance.

Then, in 2019, a fossil collector named Cliff Linster found a second specimen near Ten Sleep, Wyoming, and donated it to the same museum. This second discovery changed everything. When researchers finally examined both fossils together using computed tomography scanning—a technique that allowed them to peer inside the stone without damaging it—they realized they were looking at something genuinely unusual. The specimens belonged to an ancient family of belemnites that scientists had believed went extinct millions of years before the Jurassic period in which these animals lived. After more than two centuries of systematic belemnite research, a discovery of this magnitude was extraordinarily rare.

The new species, formally named Wyoteuthis linsterorum, possessed a skeleton unlike any belemnite previously recorded. Where its cousins were sleek and narrow, this animal was chunky—a barrel-shaped body roughly ten centimeters long but up to six centimeters wide, making it the thickest belemnite ever documented. Researchers estimate the living creature would have stretched about sixty centimeters from the tip of its body to the ends of its arms. An international team of scientists from the United States, United Kingdom, and New Zealand, led by paleontologist Dean Lomax of the University of Manchester, published their findings in the journal Papers in Palaeontology.

The unusual proportions hint at an ecological story. Belemnite expert Alexey Ippolitov, now at Victoria University of Wellington, suggested that the animal's larger size may have given it a hunting advantage over smaller belemnites of the genus Pachyteuthis, which lived in the same waters. Modern squid, after all, are opportunistic predators—they hunt other cephalopod species and sometimes even their own kind. A bigger, more robust body might have been an adaptation to a specialized diet, an evolutionary bet that paid off in one particular environment but left the species vulnerable to extinction when conditions changed.

The species name, linsterorum, honors Cliff Linster and his family. Linster was no stranger to significant fossil discoveries; his family had previously found Bambiraptor, a small dinosaur that became scientifically important. He knew that researchers were studying his belemnite and was eager to see it formally described. He died in June 2024, before the paper was published. Dean Lomax, who had spent time digging fossils with Cliff and his wife Sandy years earlier, said it was bittersweet that Linster did not live to see his name immortalized in the paleontological record. Yet that immortalization now stands: a creature from 160 million years ago, preserved in stone, carrying forward the name of the man who recognized its strangeness and trusted it to science.