Argonauta tuberculosa; Print; Argonauta nodosa; also known as the knobby or knobbed argonaut; is a species of pelagic octopus. The female of the species; like all argonauts; creates a paper-thin eggcase that coils around the octopus much like the way a nautilus lives in its shell (hence the name paper nautilus). The shell is usually approximately 150 mm in length; although it can exceed 250 mm in exceptional specimens; the world record size is 292.0 mm. A. nodosa produces a very characteristic shell; which is covered in many small nodules on the ridges across the shell; hence the specific epithet nodosa and common name. These nodules are less obvious or even absent in juvenile females; especially those under 5 cm in length. All other argonaut species have smooth ridges across the shell walls.