Yellow Cockle (also known as the Giant Atlantic Cockle)
Phylum: Mollusca, Class: Bivalvia, Order: Cardiida, Family: Cardiidae, Genus: Dinocardium, Species: D. robustum · Cardiidae (Cockle family) · Bivalve (two-shelled), whole shell, fan-shaped to heart-shaped
Species
Dinocardium robustum
Shell Type
Bivalve (two-shelled), whole shell, fan-shaped to heart-shaped
Family
Cardiidae (Cockle family)
Size
Approximately 3 to 4 inches in length and width, which is average to large for this species. Adults typically range from 2 to 5 inches.
Color & Pattern
Cream to yellowish-tan base color with distinctive reddish-brown or orange spots and blotches near the posterior margin and radiating down the ribs. The colors are natural and slightly sun-bleached on the prominent ribs.
Rarity
Common, frequently found on North Carolina beaches after storms.
Habitat
Shallow subtidal waters, intertidal zones, and sandy or muddy sand flats in marine environments.
Geographic Range
Western Atlantic Ocean, ranging from Virginia down through Florida, the Gulf of Mexico, and the Caribbean.
Description
A robust, inflated bivalve shell with deep, prominent radial ribs running from the umbo to the margin. The exterior features a strong, geometric ribbed texture with a slightly squared-off posterior end. The shell is sturdy and heavy for its size, with a cream background decorated by warm brownish-orange speckles.
Key Features
Distinguished by its large, inflated heart-shaped profile when viewed from the side, numerous strong radial ribs (typically around 32 to 36), and characteristic reddish-brown spots marking the exterior ribs.
Collector Value
Moderately popular among beachcombers and beginner-to-intermediate shell collectors. Whole, undamaged specimens with good color patterns usually sell for a few dollars in shell shops.
Condition Notes
Good condition with intact structure and prominent ribs. Minor wear and sun-bleaching consistent with beach collection, but overall a solid, attractive specimen suitable for a collection graded as Fine.
Interesting Facts
Cockles are capable of using their strong, muscular foot to leap or dig rapidly into the sand to escape predators like carnivorous snails and sea stars.
Ecological Role
Serves as a filter feeder helping to maintain water quality in coastal ecosystems. It forms an important part of the marine food web as prey for various fish, rays, and carnivorous mollusks.
Similar Species
Magnum Cockle (Vepricardium magnum), which tends to be more elongated and has different rib ornamentation; and the Prickly Cockle, which features distinct spines along the ribs.
Beach Finding Tips
Look along sandy ocean-facing beaches in North Carolina, especially right after a heavy storm or during extreme low tides when offshore sand bars are exposed.
Notes
NC beaches