Transverse Ark
Anadara transversa
(Say, 1822)
Family Arcidae
The Transverse Ark is longer than most of the arks and has what appears to be two wings on each side.
Three examples of Transverse Arks from S. Hutchinson Island (2020)
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Transverse Ark
Shell size to 40 mm; shell oblong, inequivalve, with left valve larger, overlapping right valve. Hinge straight. Sculpture of 30-35 radial ribs. Smallest species in genus Anadara. Periostracum dark-brown. Color white. This species has been reported in an 2012 article published by Susan Hewitt in The Festivus as the most common shell found on Sanibel beaches.