S. bideni is the closest find so far made to the common ancestor of octopus and squid
magazine in 2010, described Goldman Sachs, an American bank, as a “vampire squid”, he traduced an innocent animal. Vampire squid are not vampires. They actually feed on detritus, rather than living prey. They are not squid, either. They are more closely related to octopuses, on the road to which they seem to be an evolutionary staging post.
Real squid belong to a group of cephalopods called the Decabrachia . Vampire squid and octopus belong to another, the Vampyropoda . Unlike octopuses, however, vampire squid have ten limbs rather than eight—though they do not have the torpedo-shaped bodies of real squid. That, plus evidence from the fossil record, confirms the idea that the groups’ common ancestor was squid-like. But when this common ancestor lived remains a mystery.
Christopher Whalen and Neil Landman of the American Museum of Natural History, in New York, think, however, that they are close to an answer. As they write inSyllipsimopodi bideni dates from between 323m and 330m years ago, during the Carboniferous period. The previous candidate for the title was, of which this is the only known specimen, was lying neglected in a drawer in the Royal Ontario Museum, in Canada, until Dr Whalen chanced across it on a visit, while looking for something else.