Echinarachnius parma
Template:Taxobox begin Template:Taxobox begin placement Template:Taxobox regnum entry Template:Taxobox phylum entry Template:Taxobox classis entry Template:Taxobox ordo entry Template:Taxobox subordo entry Template:Taxobox familia entry Template:Taxobox genus entry Template:Taxobox species entry Template:Taxobox end placement Template:Taxobox section binomial Template:Taxobox end
The Common Sand Dollar (Echinarachnius parma) is a species of sand dollar native to the Northern Hemisphere. It is circumpolar, and can be found on the North American east coast from New Jersey north, as well as in Alaska, British Columbia, Siberia and Japan. It inhabits isolated areas on sandy bottoms below the low tide level down to a depth of 5,000 ft.
The tests (shells) of these sand dollars are round, flat and disc-like, typically measuring 3" in diameter. The entire shell is also covered with maroon-colored moveable spines. Color is a purplish brown, but they become bleached white when washed ashore. As in other echinoderms, five radial furrows branch from the mouth on the animal's underside.
This and other species of Echinarachnius have been around since the Pliocene.