Arthropods are animals with a segmented body, external skeleton, and jointed appendages. The Arthropoda includes insects and crustaceans. Only two groups of arthropods are common as fossils in the Cretaceous of the C&D Canal area, and both are types of crustaceans: the Malacostraca (crabs, lobsters, and shrimp) and the microscopic Ostracoda.
The most common crustacean fossils come from the ghost shrimp Callianassa. Pieces of the claws and pinchers are the most common body parts found; only around the area of the Deep Cut have complete appendages been found. More common than body parts are the burrows of this shrimp, which occur as lumpy tubes called called Ophiomorpha nodosa. These "trace fossils" are very common in the Englishtown and Marshalltown formations.
Occasionally, small crabs (Tetracarcinus subquadratus) or fragments of lobsters (Hoploparia gabbi) are found on some of the spoil areas from the Merchantville and Marshalltown Formations.
Ostracodes can be collected by studying the sand-sized residue from screenings of the Mount Laurel Formation.