screw or worm shell | caracol gusano
Shell is extremely irregular (particularly at larger sizes) in shape, and coiled in a short cylinder when young and producing straightened tube as an adult. Sculpture consists of closely spaced ribs when young, becoming more reticulate (net-like pattern) as an adult.
Size: 30-40 mm.
Ecology: inhabits shallow-offshore marine (10-100 m) waters, free-lying on sediment surface with apertural part of the shell directed into the water column; filter-feeding.
Geological range: Early Miocene-Late Pliocene (20-3 million years ago).
Geographic distribution: Caribbean – Panama, Colombia, Costa Rica, Florida, Mexico, Trinidad, and Venezuela; Pacific – Panama and Ecuador.