Its habitat was the shallows seawards of a major river delta in what at that time was an inland ocean between the Midwest and the Appalachians.

The fossil lacks arm hooks and suckers and all of these factors combine to make the assigning of the order Cirroctopoda controversial.

Despite the number of arms being unclear, the fact that the fossil has an indistinct head, sac like body and similar fins to cirrate octopods gives enough evidence to classify Pohlsepia mazonensis in the order Cirroctopoda.

The bulbous body outline and presence of appendages more likely to show the affinity as a cnidarian, a phylum of invertebrate animals including jellyfish and sea anemones.

The Pohlsepia mazonensis fossil was found specifically in the Pit 11 region, within the Francis Creek Shale Member.

[7] Like most soft tissue fossils found in Mazon Creek, it is preserved as a 2D light-on-dark discolouration of the matrix.

[8] The Francis Creek Shale Member of the Carbon Formation has a diverse array of preserved plants and animals.