Rossia megaptera, also known as the big-fin bobtail squid, is a species of bobtail squid native to the northwestern Atlantic Ocean, specifically Davis Strait, western Greenland, and off New York, in Hudson Canyon. It lives at depths from 179 to 1,536 m. It can grow up to 41 mm in mantle length. This type specimen was collected in the northwestern Atlantic Ocean and is deposited at the Peabody Museum of Natural History in New Haven, Connecticut.