This beautuful shell ( Argonauta Nodosa) is one of the two largest in this species, this one being the most interesting and exotic. It is not strictly a shell but an egg case of a female and in addition, the paper nautilus is not a nautilus but a member of the order Octopoda ( which includes the Octopuses ) and the family of Argonautidae.
It has a pelagic existence in that it travels the globe in free ocean waters away from the bottom and near the surface. It is a resident of all tropical and sub-tropical oceans.
Argonauta shells are washed ashore globally but the collection of an animal still resident in its egg case is very rare indeed.
The case can reach up to sixteen inches.
My wife Heather was fortunate enough to find this one on Gooseberry Flat beach, Great Barrier Island, New Zealand.
Fuji S6500 at 20mm, 1/280, f/4. iso 200.
Please view large.