Malacology is the study of mollusks. This includes animals like octopus, snails, slugs, and clams. It is the second largest phylum of animals, making them one of the most successful groups on the planet. There are over 80,000 described species of mollusks with many more left to be discovered. Mullusca is composed of 8 recognized classes including Cephalopoda, Gastropoda, Polyplacophora, Scaphapoda, Monoplacophorans, the Aplacophorans, Caudofoveata and Solenogastres, and Bivalvia.
The paper nautilus is not really a nautilus at all! It is actually a type of octopus. This species has dramatically different looking males and females. Males and much smaller and do not have shells. So, all shells from the paper nautilus that you find belonged to a female!
MolluscaBase eds. (2022). MolluscaBase.�Argonauta argo�Linnaeus, 1758. Accessed through: World Register of Marine Species at: https://marinespecies.org/aphia.php?p=taxdetails&id=138803 on 2022-01-12