Extinct 10-armed cephalopod named after President Joe Biden

March 8 (UPI) -- Scientists have named a now-extinct relative of the octopus that has 10 arms after President Joe Biden -- the syllipsimopodi bideni -- according to a study released Tuesday.

The study, published in the journal Nature Communications, said the vampyropod fossil was discovered in the Bear Gulch Limestone in Fergus County, Mont., and donated to the Royal Ontario Museum in Canada in 1988.

It wasn't until recently, though, that scientists from the American Museum of Natural History in New York City and Yale University's Department of Earth and Planetary Sciences examined fossil.

The researchers said the syllipsimopodi bideni lived during the Carboniferous period, about 328 million years ago. It's the oldest vampyropod ever discovered, pushing the group's fossil record back by about 82 million years.

Vampyropods are a group of cephalopods that includes octopuses and vampire squid.

The fossil, which is several centimeters long, indicates the syllipsimopodi bideni had a gladius, or a hard internal body part, 10 arms with suckers, two of which may have been elongated.

Christopher Whalen, a postdoctoral researcher at the AMNH's Division of Paleontology and author of the study, said the syllipsimopodi bideni is the first and only known vampyropod to have 10 functional appendages.

"The arm count is one of the defining characteristics separating the 10-armed squid and cuttlefish line (Decabrachia) from the eight-armed octopus and vampire squid line (Vampyropoda)," he said. "We have long understood that octopuses achieve the eight-arm count through elimination of the two filaments of vampire squid, and that these filaments are vestigial arms.

"However, all previously reported fossil vampyropods preserving the appendages only have eight arms, so this fossil is arguably the first confirmation of the idea that all cephalopods ancestrally possessed 10 arms."

The researchers said that since vampyropods have soft bodies, they don't typically make good fossils, saying the one held by the Royal Ontario Museum is "exceptionally well-preserved."