Nodipecten fragosus (Conrad, 1849) - Northern Lion's Paw
Broadly fan-shaped, posterior auricles meeting dorsal margin at 90° angle, hinge of right valve overlapping left (so articulated valves appear to have recessed umbo), compressed, solid, dark maroon to red or orange or lemon yellow (see inset), with ca. eight coarse radial ribs covered by numerous riblets and large knobs arranged in commarginal rows; interior whitish, darker at margins, with radial ribs reflecting exterior pattern. North Carolina to Florida, Gulf of Mexico. Length 70 mm (to 150 mm). Formerly known as Lyropecten nodosus (Linnaeus, 1758) (Caribbean and South America). Nodipecten nodosus has nine radial ribs, and so "looks" wider than JV. fragosus, with coarser macrosculpture and less tendency to develop knobs on the ribs; the hinge of its right valve does not overlap that of its left valve as is true in N. fragosus. Note: This species is common on wrecks and artificial reefs.