Fossil Octopuses


Note: Phil welcomes discussion on this article in the Cephalopod Fossils forum.

Fossil Octopuses
Fossils of octopuses are by far the most enigmatic and mysterious of all the ancient groups of cephalopods. Due to their delicate structure fossils of these animals are exceptionally rare, as the soft-bodied nature of the animal does not lend itself to fossilisation. They are so unusual that there is just one known from Illinois, one from France, a handful from Lebanon and a couple of jaw fragments from Japan and Vancouver Island. In almost three hundred million years of octopod existence, the fossil record currently comprises just eight species in six genera - our entire record would fit inside a suitcase!

Very little is known about ancient octopus history, how they evolved and developed, or their lifestyle. Following is a brief look at some of the theories surrounding them, the octopus fossils themselves and the sites they were found in. These ancient forms almost certainly do not represent a single line of descent.

A little background may be of assistance in trying to understand these fossils. If we travel back in time to the Late Devonian period (408-360m) practically all the cephalopods we would find were the externally-shelled nautiloids. The very earliest ammonoids were starting to appear in forms known as goniatites, and living alongside them were a strange off shoot of the nautiloids known as the bactritids. These bactritids had long straight conical shells and share similarities with not only the ammonoids, but also the belemnoids...
To continue reading, and to view / access full images and attachments, please sign in or sign up. You'll gain full access to all TONMO articles, and join the Internet's longest-running cephalopod community! Log in or register now.
About the Author
Phil joined the staff in April 2003. He collects fossils as a hobby, frequently plundering a quarry at Folkestone in the U.K. He has a degree in British archaeology and works for a government department at Dover in England.


HI @wtacollins, @Phil may have other insights, but FWIW, based on this recent post on TONMO, I'd say that's probably a sea urchin:
Hi ya. Glad you liked the article. Yes that is a sea urchin, or rather concretion that has broken off the fossil, so it is concave - a 'negative', if you will. If you push some blu-tac into it and carefully pull it out without bending it, you can imaging that is the surface of the sea urchin (that's a highly scientific method for you). Here is a similar one I found in a pebble on a beach in Deal in Kent, UK, when I was very young. It's mid-Cretaceous and from flint. I'd imagine yours is similar.


Article information

Last update

More in Cephalopod Fossils

More from Phil