Argonautidae is a family of cephalopods encompassing the modern paper nautiluses of the genus Argonauta along with several extinct genera of shelled octopods.
All eggcases possessing nodes, ribs, and a double keel, with the exception of those of Kapal batavus, have been assigned to Argonauta. Eggcases lacking these morphological features have been placed in the other Argonautidae genera.[1]
Fossil Argonautidae eggcases have been described from Japan, New Zealand, Sumatra, Europe, and California.[1]
Similar families occurring in the area
No other cephalopods produce a shell-like egg case.
Octopodidae: lack a funnel locking apparatus and
males are not dwarves, nor do their hectocotyli develop
in a sac.
Ocythoidae and Tremoctopodidae: have water pores
on their heads;whereas male argonautids are usually
hectocotylized on the left side, males of the latter 2
families are usually hetocotylized on the right; the
hectocotylus pouch in ocythoids is stalked, and female
tremoctopodids have an extensive web connecting
the dorsal and dorsolateral arms.