Friday Squid Blogging: 500-Million-Year-Old Squid
New Canadian research into 500 million-year-old carnivore fossils has revealed an early ancestor of modern-day squids and octopuses, solving the mystery surrounding a previously unclassifiable creature.
“This is significant because it means that primitive cephalopods were around much earlier than we thought, and offers a reinterpretation of the long-held origins of this important group of marine animals,” Martin Smith, University of Toronto and Royal Ontario Museum paleontology PhD student, said in a release.
This was one of those confusing, uninterpretable Cambrian animals, represented by only one poorly preserved specimen. Now, 91 new specimens have been dug up and interpreted, and it makes sense to call it a cephalopod. It has two camera eyes—not arthropod-like compound eyes—on stalks, an axial cavity containing paired gills like the mantles of modern cephalopods, and a flexible siphon opening into that cavity. There are also subtle similarities in the structure of the connective tissue in the lateral fins. Obviously, it has a pair of tentacles; no mouthparts have been preserved, but there are hints in the form of dark deposits between the tentacles, which may be all that’s left of the mouthparts - and are in the right place for a cephalopod ancestor.