Styletoctopus

Name: Styletoctopus ‭(‬Stylet octopus‭)‬.
Phonetic: Sty-let-ok-toe-pus.
Named By: Dirk Fuchs,‭ ‬Giacomo Bracchi,‭ ‬Robert Weis‭ ‬-‭ ‬2009.
Classification: Mollusca,‭ ‬Cephalopoda,‭ ‬Octopoda,‭ ‬Octopodidae.
Species: S.‭ ‬annae‭ (‬type‭)‬.
Diet: Carnivore.
Size: Unavailable.
Known locations: Lebanon.
Time period: Cenomanian of the Cretaceous.
Fossil representation: Specimen preserved flat on a rock slab.

       In‭ ‬2009‭ ‬Styletoctopus was one of two genera of extinct prehistoric octopuses presented to the world,‭ ‬the other being Keuppia.‭ ‬The fact that octopus fossils were found at all is worthy of headline news since with the exception of a hard keratinous beak,‭ ‬octopuses that we know today are entirely made up of soft muscle tissue,‭ ‬something that very rarely fossilises,‭ ‬and then usually only as an impression upon the rock.‭ ‬Styletoctopus was preserved flat upon a rock,‭ ‬and displays the outlines of eight arms,‭ ‬something that confirms its identity as an octopus and not another kind of cephalopod such as a squid‭ (‬which for clarity typically have ten arms‭)‬.‭ ‬Styletoctopus however does also appear to have been a very primitive octopus since it has also been found with the remains of a gladius.‭
       A gladius is in essence an internal shell,‭ ‬and a remnant of the outer shells that the ancestral forms of Styletoctopus would have possessed.‭ ‬This means that Styletoctopus was not as advanced as modern octopuses,‭ ‬and while other cephalopods such as squid and cuttlefish do retain internal shells,‭ ‬the closest match for the gladius of Styletoctopus is actually the vampire squid,‭ ‬Vampyroteuthis infernalis.‭ ‬This does fit with fossil evidence since ancient relatives of the vampire squid,‭ ‬typically the genus Vampyronassa have been found in Jurassic age rocks,‭ ‬and together all of these genera may represent a diversification and radiation of cephalopod forms that eventually evolved into today’s modern forms.
       Also because the gladius in Styletoctopus is still quite large when compared to modern forms,‭ ‬it‭’‬s not impossible that Styletoctopus may have been more pelagic‭ (‬living in open water‭) ‬than many of today‭’‬s octopuses.‭ ‬This is because of the internal shell,‭ ‬being bigger and less flexible,‭ ‬would have been a hindrance if a Styletoctopus‭ ‬ever tried to squeeze into a rock crevice to hide from possible predators.‭ ‬Finally the gladius of Styletoctopus is also the inspiration for the genus name since the internal shell is shaped like a stylet,‭ ‬a type of flint point also known as a Minet ed Dhalia point which are found in Lebanon,‭ ‬as was the Styletoctopus holotype fossil.

Another prehistoric octopus genus discovered from Lebanese fossil deposits is Palaeoctopus.

Further reading
NEW OCTOPODS‭ (‬CEPHALOPODA:‭ ‬COLEOIDEA‭) ‬FROM THE LATE CRETACEOUS‭ (‬UPPER CENOMANIAN‭) ‬OF HAKEL AND HADJOULA,‭ ‬LEBANON,‭ ‬Dirk Fuchs,‭ ‬Giacomo Bracchi,‭ ‬Robert Weis‭ ‬-‭ ‬31st Dec‭ ‬2008‭ (‬pub January‭ ‬2009‭)



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