It’s hard to picture a squid in Wyoming, but 160 million years ago as global sea levels rose and the Pacific Ocean flooded into Wyoming, it was rife with ancient relatives of squids. In fact, deposits of sediment where the “Sundance Sea” once existed have yielded countless fossils of long extinct ammonites and belemnites.
Now, a new study published in Papers in Palaeontology by researchers from the U.S., U.K., and New Zealand reports on two fossils of a belemnite with particularly unusual characteristics. The name of the new species—Wyoteuthis linsterorum—honors late fossil collector Cliff Linster who found the second specimen.
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Belemnites were shaped like bullets—cylindrical bodies with squid-esque butts protected by a hard exterior called “rostrum.” Belemnites from Wyoming are typically only a few inches long and skinny, no more than three-quarters of an inch in diameter. But the newly discovered species is almost 2.5 inches wide, the thickness of a soda can, and would have extended roughly two feet long, prompting study co-author and paleontologist Bill Wahl to comment in a press release that it “stuck out like a sore thumb” among the fossil finds.
Its body had bilateral symmetry, or two mirror halves, as you’d expect. But the sides of the ancient creature were flattened, and its nose was uncharacteristically broad and blunt for a Late Jurassic belemnite. Belemnites with stocky bodies and blunt noses—in the genus Rhopaloteuthis—from the same period have been found in Europe. However, since they’re from completely different lineages, the similarities between Wyoteuthis and Europe’s Rhopaloteuthis likely “reflect some local ecological adaptations to similar environments,” the researchers theorize.
Also, Wyoteuthis is rare in the Sundance formation, outnumbered by hundreds of smaller belemnites in the genus Cylindroteuthid, suggesting a narrow ecological niche. It may have been highly specialized by choice of prey, perhaps even feeding on smaller belemnites in the area. “Or, alternatively, the main habitat area of Wyoteuthis could be located along the oceanic shelf, while only occasional specimens entered the gulf-like Sundance Sea,” according to the paper.
Either way, it was certainly a giant among belemnites. 
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Lead Image: Illustration of Wyoteuthis linsterorum by Jason Poole © Courtesy of Jessica Lippincott
