According to a study published in Nature Communications on Tuesday, a fossil named after President Joe Biden is believed to be the oldest known ancestor of the octopus.
The Greek words for "prehensile" and "syll" were used to derive the name of the animal.
The earliest known relative of the vampire squid, the animal, which lived around 330 million years ago in Montana, had a torpedo-like body, 10 arms, fins, and rows of suckers.
The researchers wrote that one arm was longer than the others and was likely used to catch prey.
It is the oldest known animal with 10 appendages, and is the first and only one to do that, according to Christopher Whalen, a researcher at the American Museum of Natural History and Yale University.
The researchers said the discovery supports the idea that the ancestors of the cephalopods had eight arms and that they lost two arms over time.
The paper was accepted for publication shortly after Biden's inauguration and the Capitol insurrection.