Chelodidae is an extinct of
polyplacophoran
Chitons () are marine (ocean), marine molluscs of varying size in the class (biology), class Polyplacophora (), formerly known as Amphineura. About 940 Extant taxon, extant and 430 fossil species are recognized.
They are also sometimes known ...
mollusc.
References
Prehistoric mollusc families
Chitons
{{paleo-mollusc-stub