Phylum Mollusca
Class Pelecypoda
Pelecypods have two shells, or bivalves, that protect the soft parts of the animal. The valves are generally of equal size (except in groups like the oysters) and shape and are hinged at the back. Some types, such as oysters, live in large groups that create beds or low-relief banks of shells, where the animals feed by filtering plankton and organic debris from the water. Other bivalves burrow through the mud or swim about in search of debris to eat. Many bivalve fossils in Delaware are preserved as steinkerns. Pelecypods are abundant in the spoils from the Mount Laurel Formation on both sides of the Canal in the vicinity of Reedy Point.
- Introduction
- Piedmont Geology
- Overview of the Piedmont
- Geologic History of the Delaware Piedmont
- Common Rocks and Minerals of the Delaware Piedmont
- Deformation in the Piedmont
- Piedmont Rock Units
- Piedmont Rock Unit Descriptions
- Ardentown Granitic Suite
- Baltimore Gneiss
- Barley Mill Gneiss
- Biotite Tonalite
- Brandywine Blue Gneiss
- Bringhurst Gabbro
- Christianstead Gneiss
- Cockeysville Marble
- Faulkland Gneiss
- Iron Hill Gabbro
- Metapyroxenite and metagabbro (undifferentiated)
- Mill Creek Metagabbro
- Montchanin Metagabbro
- Pegmatite
- Perkins Run Gabbronorite Suite
- Rockford Park Gneiss
- Serpentinite
- Setters Formation
- Windy Hills Gneiss
- Wissahickon Formation
- Selected Outcrops of the Delaware Piedmont
- Map of Selected Piedmont Outcrops
- Outcrop Ba14-a: The Setters Formation at Avondale Quarry
- Outcrop Bb25-c: The Yorklyn Railroad Cut
- Outcrop Bc32-a: The Mt. Cuba Picnic Grove
- Outcrop Bc32-b: The Mt. Cuba Railroad Cut
- Outcrop Bc44-f: The Tatnall Preschool Grounds
- Outcrop Bd21-a: Boulder Field at Brandywine Creek State Park
- Outcrop Bd41-b: Rockford Park Gneiss Boulders at Rockford Park
- Outcrop Bd42-e: The Cliffs of Alapocas Woods
- Outcrop Bd44-b: Bringhurst Gabbro boulders in Shellpot Creek
- Outcrop Be22-e: Ardentown Railside Boulders
- Outcrop Be21-e: Hanby Park Quarry
- Outcrop Be22-k: Charnockite Boulders at Ardentown
- Outcrop Be23-g: Charnockite Boulders in the South Branch of Naaman Creek
- Outcrop Be32-g: Lesher Park Streambed
- Outcrop Ca44-d2: The Christianstead Subdivision
- Outcrop Cb15-c: The Confluence Quarry at North Pointe
- Outcrop Cb42-c: Windy Hills Bridge Outcrop
- Outcrop Cc12-a: The Cave at Brandywine Springs
- Outcrop Cc12-c: The Red Clay Creek Edge
- Outcrop Da15-h: The Paraglacial Boulder Feature of Chestnut Hill
- Piedmont Field Trips - GeoAdventures
- Coastal Plain Geology
- Geologic History of the Delaware Coastal Plain
- Coastal Plain Rock Units (Stratigraphic Chart)
- Coastal Plain Rock Unit Descriptions
- Assawoman Bay Group
- Beaverdam Formation
- Bethany Formation
- Bridgeton Formation
- Bryn Mawr Formation
- Calvert Formation
- Cat Hill Formation
- Choptank Formation
- Columbia Formation
- Cypress Swamp Formation
- Deal Formation
- Delaware Bay Group
- Englishtown Formation
- Hornerstown Formation
- Ironshire Formation
- Kent Island Formation
- Lynch Heights Formation
- Magothy Formation
- Marshalltown Formation
- Manasquan Formation
- Merchantville Formation
- Mt. Laurel Formation
- Nanticoke River Group
- Navesink Formation
- Old College Formation
- Omar Formation
- Piney Point Formation
- Potomac Formation
- Scotts Corners Formation
- Shark River Formation
- Sinepuxent Formation
- St. Marys Formation
- Turtle Branch Formation
- Vincentown Formation
- Hydrogeology
- Mineral Resources
- Natural Hazards
- Natural Hazards in Delaware
- Earthquakes
- Stream and Tide Gage Data for Hurricane Sandy
- Fossils
- What is a fossil?
- Dinosaurs in Delaware?
- Fossil Sites In Delaware
- Fossil Identification Sheet
- Cretaceous Fossils of the C&D Canal
- Cretaceous Fossils Overview
- One-celled Organisms: Phylum Protozoa
- Sponges: Phylum Porifera
- Clams, Snails, and Squid: Phylum Mollusca, Class Gastropoda
- Clams, Snails, and Squid: Phylum Mollusca, Class Cephalopoda
- Clams, Snails, and Squid: Phylum Mollusca, Class Pelecypoda
- Corals and Jellyfish: Phylum Cnidaria
- Insects and Crustaceans: Phylum Arthropoda
- Lamp Shells: Phylum Brachiopoda
- Moss Animals: Phylum Bryozoa
- Segmented Worms: Phylum Annelida
- Starfish and Urchins: Phylum Echinodermata
- Vertebrates: Phylum Chordata
- Miocene Fossils of Pollack Farm


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