-Animals (Kingdom Animalia)

-Arthropods (Phylum Arthropoda)

-Crustaceans (Subphylum Crustacea)

-Typical Crustaceans (Superclass Multicrustacea)

-Malacostracans (Class Malacostraca)

-Decapods, Isopods, and Allies (Subclass Eumalacostraca)

-Decapods and Krill (Superorder Eucarida)

-Decapods (Order Decapoda)

-Crabs, Lobsters, Shrimps, and Allies (Suborder Pleocyemata)

-True Crabs (Infraorder Brachyura)​

-Eubrachyuran Crabs (Zoosection Eubrachyura)

-Thoracotrematan Crabs (Zoosubsection Thoracotremata)

-Land, Shore, and Marsh Crabs (Superfamily Grapsoidea)

-​Land Crabs (Family Gecarcinidae)

-Sesarmid Marsh Crabs (Family Sesarmidae)

-Square-back American-Marsh Crabs (Genus Armases)

These crabs are usually found in intertidal zones and can be found up to 50 m inland; they can thrive in a variety of habitats as well. Individuals are common among rubble and litter above the intertidal zone. While these crabs are often deemed to be detritivores, they are highly omnivorous and will supplement a detritus diet with microscopic insects and invertebrates.