In the rocks of Wyoming, where the ancient Sundance Sea once splashed, paleontologists stumbled upon an unusual find: fossils that break the familiar image of belemnites — those extinct marine creatures that resembled squids.
Most known belemnites were slender and elongated, leaving behind "bullet-shaped" rostra. The new species Wyoteuthis linsterorum, described from two specimens, turned out to be quite different: its barrel-shaped rostrum reaches about 10 centimeters in length and 6 centimeters in width at its thickest part. This makes it the "fattest" belemnite of all known to science.
With its soft parts — tentacles and fins — the animal apparently reached roughly 60 centimeters in length. A short and stocky body may have helped in maintaining buoyancy or in hunting at depth, where speed and maneuverability matter more than slenderness. Such adaptations probably allowed Wyoteuthis linsterorum to pursue faster prey in the water column of the Jurassic ocean.
The find dates to approximately 160 million years ago. The fossils were discovered and donated to the collection by Cliff Linster, after whom the species is named. So far only two specimens are known, which speaks to the rarity of this marine predator. In the same layers, more common Pachyteuthis are frequently found, but Wyoteuthis linsterorum stands out sharply among them.
The discovery is a reminder of how incomplete the picture of ancient life remains. Even in well-studied formations, forms continue to be found that change our understanding of the diversity and ecology of extinct groups. In the Jurassic seas, where large plesiosaurs also lived, such "fatties" may have played their own special role in the food chains.
Every such discovery helps us better understand how Earth's oceans changed over millions of years and what niches their inhabitants occupied.
