Class Polyplacophora is a group of marine mollusks commonly known as chitons. Synonyms for this class include the name Amphineura, which refers to the absence of a distinct head or tail region in these organisms. The name Acanthochitona is also sometimes used to refer to this class, which reflects the spiny texture of the shells of some species. Other possible synonyms may include the names Mollusca Polyplacophora and Polyplacophores, which are simply alternative ways of referring to this particular group of organisms within the broader category of mollusks. Regardless of their name, chitons remain an interesting and unique example of the rich diversity of life found in our oceans.