Dinocardium robustum (Atlantic giant cockel shell) (eastern coast of Florida, USA) 2

Description:

Description: English: Dinocardium robustum Lightfoot, 1786 - interior surface of an Atlantic giant cockle shell (modern) from Florida, USA. Bivalves are bilaterally symmetrical molluscs having two calcareous, asymmetrical shells (valves) - they include the clams, oysters, and scallops. In most bivalves, the two shells are mirror images of each other (the major exception is the oysters). They occur in marine, estuarine, and freshwater environments. Bivalves are also known as pelecypods and lamellibranchiates. Bivalves are sessile, benthic organisms - they occur on or below substrates. Most of them are filter-feeders, using siphons to bring in water, filter the water for tiny particles of food, then expel the used water. The majority of bivalves are infaunal - they burrow into unlithified sediments. In hard substrate environments, some forms make borings, in which the bivalve lives. Some groups are hard substrate encrusters, using a mineral cement to attach to rocks, shells, or wood. The fossil record of bivalves is Cambrian to Recent. They are especially common in the post-Paleozoic fossil record. The whitish circles and spots on this shell are barnacle encrustation scars. Classification: Animalia, Mollusca, Bivalvia, Heterodonta, Veneroida, Cardiidae Locality: beach along the Atlantic coast of Florida, USA See info. at: en.wikipedia.org/wiki/Dinocardium_robustum. Date: 29 September 2020, 16:41:05. Source: https://www.flickr.com/photos/47445767@N05/50407152782/. Author: James St. John.