Newly discovered fossils have pushed back the age of origin of octopuses, according to a study published in a recent issue of the journal Palaeontology.
Octopus fossils are extremely rare, because their bodies lack significant hard parts (being composed almost entirely of muscle, skin and viscera) that can be fossilized.
Upon death, an octopus decomposes rapidly and barring unusual conditions, will leave nothing behind in the fossil record.
Such soft-body preservation is so rare that Mark Purnell, for the Palaeontological Association, remarked that finding an octopus as a fossil is about as unlikely as finding a fossil sneeze.
This is why, prior to this study, only one species of fossil octopus was known, and from fewer specimens than an octopus has limbs.
The paper by Dirk Fuchs, Giacomo Bracchi and Robert Weis describes three new species of fossil octopus placed in two new genera (Keuppia and Styletoctopus).
The descriptions are based on exceptionally well-preserved fossils from the Cenomanian (93"100 million years ago) deposits in Lebanon, with the three new species being named Keuppia levante, K. hyperbolaris and Styletocopus annae.
The fossils preserve the outlines of the octopuses so well that traces of muscles, suckers and even the internal gills and ink can be made out.
These new fossil octopuses are remarkably similar to their living relatives, implying that octopus origins are tens of millions of years older than previously thought.
For more information, see the paper: Fuchs, D, G Bracchi and R Weis (2009) New Octopods (Cephalopoda: Coleoidea) from the Late Cretaceous (Upper Cenomanian) of Hakel and Hadjoula, Lebanon. Palaeontology 52, pp. 65"81.