astronomy-to-zoology:

Genus Argonauta

(literally meaning Sailor on the Argo)

Commonly known as the paper nautilus as they bare some resemblance to a nautilus, but in fact they are a group of octopi. they are called paper nautili because the females excrete a paper thin eggcase, not a true shell. they can be found in tropical open ocean waters worldwide, closer to the surface than other ocotpi which usually live near the seabed. they can be identified by the females “shell” large eyes and unique mantle, they are extremely dimorphic as females have a shell and grow up to 10cm with a shell of 30cm, but males are alot smaller at 2cm and no shell. they got their name sailor on the argo from the historical misconception that they sail on the surface using their tentacles, this was mentioned in 20,000 leauges under the sea

Phylogeny

Animalia-Mollusca-Cephalopoda-Octopoda-Argonautoida-Argonautidae-Argonauta