Shells are thin, ovate, inequilateral, and strongly convex. Sculpture has concentric growth lines, which become finer when mature.
Size: 50-65 mm.
Ecology: inhabits shallow marine (5-50 m) waters, burrowing in silt below the sediment surface.
Geological range: Early Miocene-Late Miocene (23-8 million years ago)
Geographic distribution: Caribbean – Panama, Brazil, Colombia, Costa Rica, Trinidad, and Venezuela; Pacific – Panama, Ecuador, Mexico, and Peru.