Oldest "Octopus" Fossil Revealed as Ancient Squid Relative

A fossil celebrated as the world's oldest known octopus has been misidentified for decades. New scientific analysis shows the 300-million-year-old creature is actually a relative of the nautilus. The animal, named *Syllipsimopodi bideni*, was discovered in Montana's Bear Gulch limestone. It was originally classified as a "vampyropod." This group includes modern octopuses and vampire squid. Its age suggested octopus ancestors evolved much earlier than believed. Recent research, published in *Nature Communications*, re-examined the fossil. Scientists found a key feature: a rigid internal shell. True octopuses lack this structure. The fossil's shell matches those found in early nautiloids. This correction reshapes the evolutionary timeline. Octopuses likely appeared more recently. The ancient fossil now provides crucial insight into the diverse, shelled ancestors of modern squid and nautilus species.