What do you call a 328 million-year-old fossil octopus with 10 arms? A decapus? A kraken? The researchers who analyzed the fossilized monster from Montana went in a different direction — and came up with a name that pays tribute to President Joe Biden.
The scientific label for the sea monster from the days before the dinosaurs, Syllipsimopodi bideni, isn’t intended as a comment on the 79-year-old politician’s age. “Bideni” merely recognizes the fact that the paper describing the species was submitted to the journal Nature Communications not long after Biden’s inauguration in January 2021.
“I wanted to somehow acknowledge the moment in a way that was more positive and forward-looking,” study lead author Christopher Whalen, a researcher at the American Museum of Natural History and Yale University, said in a news release. “I was encouraged by the plans President Biden put forward to counter anthropogenic climate change, and his general sentiment that politicians should listen to scientists.”
“Syllipsimopodi” is the more scientifically meaningful part of the name: That genus designation comes from the Greek words for “prehensile foot,” and the researchers say Syllipsimopodi bideni is the oldest-known cephalopod to develop suckers on its 10 sinuous arms.
The specimen also appears to clear up some evolutionary questions about the common ancestor of present-day squids and octopuses.
“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),” Whalen explained.
Whalen and his co-author — Neil Landman, a curator emeritus at the museum — say that other characteristics of Syllipsimopodi bideni, including its soft body and the presence of an internal anatomical structure known as a gladius, put it firmly in the Vampyropoda line.
“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,” Whalen said. “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 fossil comes from central Montana’s Bear Gulch Limestone formation, which was once the site of an ancient marine bay. It was donated to the Royal Ontario Museum in 1988, where it sat waiting for Whalen and Landman to take a closer look. Their analysis extends the fossil record of vampyropods by about 82 million years.
The idea of facing a 10-armed vampyropod may sound scary, but Landman said ancient seas probably held more monstrous creatures.
“Syllipsimopodi may have filled a niche more similar to extant squids, a mid-level aquatic predator,” he said. “It is not inconceivable that it might have used its sucker-laden arms to pry small ammonoids out of their shells, or ventured more inshore to prey on brachiopods, bivalves or other shelled marine animals.”
Grants from the National Science Foundation’s Postdoctoral Research Fellowship in Biology Program and the Paleontological Society funded the research resulting in the Nature Communications study, which is titled “Fossil Coleoid Cephalopod From the Mississippian Bear Gulch Lagerstätte Sheds Light on Early Vampyropod Evolution.”
