A Jurassic squid relative from Wyoming was the chunkiest of its kind
Two rare fossils show a 160-million-year-old sea animal with a barrel-shaped body far wider than any of its known relatives.
About 160 million years ago, a sea creature swam over what is now Wyoming that looked like a squid but was built like a small barrel. Two rare fossils have now shown that it was the fattest, chunkiest member of its whole family ever found.
A skeleton far wider than the rest
The animal was a belemnite, a member of an extinct group of sea creatures that were cousins of today's squid and octopuses. Belemnites are among the most common fossils in the world. What usually survives is a hard internal skeleton called a rostrum, or guard, which is bullet-shaped.
Wyoming's Sundance Formation preserves the remains of an ancient inland sea that once stretched across much of the western United States, and it has yielded millions of these fossils. Wyoming paleontologist Jessica Lippincott, a coauthor of the study, says people in the region commonly nickname them "squid butts."
Most of the Wyoming specimens are narrow: about 5 to 10 centimeters long and only 1 to 2 centimeters across. The new species is a different shape entirely. Its skeleton is roughly 10 centimeters long but about 6 centimeters wide, making it the thickest example known. The living animal, arms included, may have reached about 60 centimeters, or roughly two feet.
Two fossils found almost thirty years apart
The first specimen was found in the late 1990s by Dr. Burkhard Pohl, founder of the Wyoming Dinosaur Center. He noticed it was considerably larger than any belemnite he had seen before, but the fossil then sat unstudied in a museum collection drawer for many years.
The second turned up when fossil collector Cliff Linster found one near Ten Sleep, Wyoming, and donated it to the Wyoming Dinosaur Center in 2019. With two specimens available for comparison, researchers finally had enough evidence to describe a new species.
They named it Wyoteuthis linsterorum. The genus name means "a squid from Wyoming," and the species name recognizes Cliff Linster and his family for their contribution.
What the wide body may have been for
Wyoming paleontologist Bill Wahl, who has devoted much of his career to searching the state for fossils, said the odd specimen "stuck out like a sore thumb" compared with the countless others found there. He assembled an international team, including belemnite expert Alexey Ippolitov, now a PhD student at Victoria University of Wellington in New Zealand, and Dr. Dean Lomax, an Honorary Research Fellow at the University of Manchester. The work was published in the journal Papers in Palaeontology.
To look inside the fossils without cutting them open, the team used a scanning method that takes X-ray pictures from many angles and builds a three-dimensional view of the inside. Those scans revealed a surprise: the animal appeared to belong to an ancient belemnite family that scientists had believed died out millions of years before it lived.
Ippolitov said he was deeply surprised to find something so unusual in a group that has already been studied for more than 200 years. He suggests the relatively large size may have given the animal an advantage when hunting smaller belemnites of the genus Pachyteuthis that lived alongside it. Modern squid, he notes, are hardly picky eaters and will hunt other squid-like animals, sometimes even their own kind.