Shell is circular to irregularly ovate in shape, and either inflated and convex (left valve) or flat (right valve). Sculpture has irregular (sometimes frilly) ridges parallel to the shell margin.
Size: 30-40 mm.
Ecology: inhabits nearshore marine waters (0-15 m), attached to shells and rocks.
Geological range: Middle-Late Miocene (14-8 million years ago).
Geographic distribution: Caribbean – Panama, Colombia, and Venezuela.