Amblema plicata shell description:

 “Shell quadrate; dorsal margin long and nearly straight, ventral margin gently rounded; anterior end uniformly rounded; posterior end truncated, ending in a squarish point.  Shell thick and solid even in young specimens; size to 18cm; moderately inflated, becoming compressed posteriorly; posterior ridge prominent; four to six prominent ridges roughly parallel the posterior ridge; a few to many curved ridges extend from the posterior ridge to the posterior and dorsal margins.  Beaks low, only slightly raised above the hinge line, inequipartite; beak sculpture, usually seen on only very young shells, consists of three or four concentric double-looped ridges.  Concentric growth-rest periods form prominent ridges and grooves.  Epidermis light brown or yellowish-green becoming dark brown to black on old shells.

Left valve has two large, triangular, grooved pseudocardinal teeth; the lateral teeth are long, slightly curved and finely striated.  Right valve has a stout, elevated, triangular, grooved pseudocardinal tooth, having a small lamellar denticle anteriorly; the lateral tooth is high, slightly curved and striated.  Interdentum broad; beak cavity deep; nacre white, often tinged with pink or purple posteriorly; local infections often stain the nacre a golden amber color, iridescent posteriorly”(Simpson, 2014; Mather, 2007).