Definition
Amphineura is an obsolete taxonomic class once used to classify certain primitive mollusks, primarily chitons and solenogasters. These creatures are characterized by elongated bodies, shells composed of multiple plates (in chitons), or lack of a shell entirely (in solenogasters). They typically inhabit marine environments. The term is no longer in wide use, as modern taxonomy has reclassified these animals into separate classes: Polyplacophora (chitons) and Solenogastres (aplacophorans). It's like an old 'folder' on your computer that has been split up.