Scientists Discover The Fattest Ancient Squid Fossil Ever Found In Wyoming

Paleontologists have identified a previously unknown species of ancient marine predator, Wyoteuthis linsterorum, which swam through the inland seas of North America roughly 160 million years ago. The discovery, detailed in the journal Papers in Palaeontology, highlights a creature that stands out for its unique physical stature, earning it the reputation as the most robust belemnite ever documented.

An Unusual Discovery in the Sundance Formation

Belemnites, an extinct group of cephalopods related to modern squid and octopuses, are among the most common fossils found worldwide. Typically, researchers uncover only the animal’s bullet-shaped internal skeleton, known as a rostrum or guard. In Wyoming’s Sundance Formation, where these fossils are abundant, they are often colloquially referred to as “squid butts.”

While standard specimens from the region typically measure between 5 and 10 centimeters in length and only 1 to 2 centimeters in width, Wyoteuthis linsterorum is significantly more substantial. Its rostrum is approximately 10 centimeters long but reaches an impressive 6 centimeters in width. Researchers estimate that the living animal, including its arms, would have spanned roughly 60 centimeters, or two feet.

A Long-Awaited Classification

The path to describing this species spans nearly three decades. The first specimen was identified in the late 1990s by Dr. Burkhard Pohl, founder of the Wyoming Dinosaur Center, but it remained unstudied for years due to its anomalous features. A second specimen, discovered by collector Cliff Linster near Ten Sleep, Wyoming, in 2019, provided the necessary evidence to define the species. The genus name Wyoteuthis translates to “a squid from Wyoming,” while the species name honors the Linster family.

Paleontologist Bill Wahl noted that the fossil stood out immediately from the thousands of other specimens in the region. Jessica Lippincott, a co-author of the study, remarked that despite her years of experience with local belemnites, this discovery was entirely unique.

Evolutionary Insights and Ecological Niche

Using computed tomography (CT) scanning, the research team examined the internal morphology of the fossils without causing damage. The scans revealed an unexpected link to an ancient belemnite family previously thought to have gone extinct millions of years before Wyoteuthis linsterorum existed.

Alexey Ippolitov, a specialist in the group based at Victoria University of Wellington, suggested that the creature’s massive size may have provided a significant predatory advantage. He noted that the animal might have hunted smaller, co-occurring belemnites, much like modern squids that exhibit opportunistic feeding behaviors, including cannibalism.

Dr. Dean Lomax, an Honorary Research Fellow at The University of Manchester, described the rarity of the find as potentially indicative of a highly specialized ecological role, suggesting that such creatures may have occupied a very narrow niche in the prehistoric Sundance Sea.