Wyoteuthis linsterorum, a Giant Belemnite, Discovered in Wyoming
Paleontologists have identified Wyoteuthis linsterorum, a remarkably thick, barrel-shaped belemnite species from Wyoming's 160-million-year-old Sundance Formation, challenging assumptions about Jurassic cephalopod diversity and size.
Scientists have identified a new species of giant belemnite, Wyoteuthis linsterorum, from fossils found in Wyoming's Sundance Formation. The creature lived approximately 160 million years ago in an ancient inland sea during the Jurassic Period, and its unusually robust skeleton makes it the chunkiest belemnite ever described.
The discovery hinges on two exceptionally rare fossils. The first was found in the late 1990s by Dr. Burkhard Pohl. A second, key specimen was discovered by fossil collector Cliff Linster in 2019, which finally enabled the formal description of the species. The genus name Wyoteuthis translates to 'a squid from Wyoming,' while the species name linsterorum honors Cliff Linster and his family. Linster died in June 2026, before the research was published, but was aware of the scientific investigation into his find.
Discovery timeline and specimen history
The identification of Wyoteuthis linsterorum was only possible after the recovery of the second specimen nearly thirty years after the first. This complete fossil, found by Cliff Linster, provided the necessary morphological detail for paleontologists to recognize it as a distinct and unprecedented species. The fossils were preserved in the sediments of the Sundance Formation, which represents a vast, shallow inland sea that once covered parts of the American West.
Scientific context and significance
Belemnites are extinct, squid-like cephalopods and are among the most commonly found fossils globally, with over two centuries of scientific study. This discovery shows that even well-understood fossil groups can still yield major surprises when unusual specimens are preserved. Wyoteuthis linsterorum represents a radical departure from typical belemnite morphology.
Typical belemnite fossils from Wyoming measure between 50 and 100 millimeters in length and 10 to 20 millimeters in width. In stark contrast, the rostrum-the dense, calcitic internal skeleton-of Wyoteuthis is exceptionally thick. It measures approximately 10 centimeters long and 6 centimeters wide, with a diameter of about 60 millimeters at its anterior end, the thickest ever recorded for a belemnite.
| Feature | Typical Wyoming Belemnite | Wyoteuthis linsterorum |
|---|---|---|
| Rostrum Length | 50-100 mm | ~100 mm (160-175 mm estimated) |
| Rostrum Width/Diameter | 10-20 mm | ~60 mm (anterior end) |
| Estimated Total Body Length | Not typically estimated | ~55-60 cm (22-24 inches) |
The species belongs to the family Megateuthididae, which includes Megateuthis, the largest known belemnite genus. Researchers estimate that including its arms and mantle, Wyoteuthis could have reached a total length of about 60 centimeters, or two feet. This size and its robust build suggest it was a significant predator. The creature may have hunted smaller belemnites of the genus Pachyteuthis, which were common in the same ancient sea.
The research also provides context for the group's evolution. Megateuthidid belemnites like Wyoteuthis thrived after the Toarcian extinction event, which caused massive ocean oxygen loss and cleared ecological space. Most of these lineages, however, went extinct by the Middle Jurassic, making this find a notable late survivor. Wyoteuthis linsterorum is the only known species in its genus, standing as a major morphological outlier in belemnite evolution.
