Pohlsepia mazonensis, an early 'octopus' from the carboniferous of Illinois, USA

Pohlsepia mazonensis gen. et sp. nov. from the Mazon Creek Konservat Lagers tatte (Carhoniferous) of Illinois is an exceptionally preserved soft-bodied fossil coleoid, with well-defined body and arms. Lacking an internal shell and possessing eight subequal and two modified arms, Pohlsepia can be comp ared with both the living cirrate octopods and the decabrachian sepiardarid s, both of which lack a well-developed internal skeleton. Given its sac-lik e body, lack of a well-defined head and presence of fins, Pohlsepia can be safely compared with modern cirrate octopods, it is the oldest known comple tely soft-bodied coleoid and as such has great significance with respect to the phylogeny of the group, given that both the octobrachian and decabrach ian clades have previously been thought to have evolved in the Jurassic.