Articulated specimen of Acutichiton allynsmithi (Mollusca, Polyplacophora) from Oklahoma

Articulated specimens of polyplacophorans are rare in the geological record, most being found as isolated valves. When found, it is useful to illustrate articulated specimens to provide a basis for making correct associations of isolated valves, to substantiate valve associations already proposed, and to determine valve order and amount of valve overlap.