Ponderous ark

Noetia ponderosa

Family Noetiidae - arks

Bivalve (2 shells); shell ovate, inflated, anterior end rounded, posterior end more angular with nearly straight upper margin; color white, protective covering (periostracum) brown, hairy; interior white, margins crenate (scalloped); flattened radial ribs with fine concentric grooves crossing ribs and in between ribs; hinge margin straight on top, slightly curved on bottom; hinge area wide, beak twisted toward posterior end; posterior end with ridge from beak to posterior margin; posterior abductor muscle scar with raised ridge.
Similar Species
The flattened ridged posterior end and raised ridge on the posterior muscle distinguish this ark.
Gulf and bay, sandy bottoms
Maximum Size
7.6 cm (3 in)
Other Common Names
Previous Scientific Names