Black dogfish to the clade formed by the granular dogfish ("C. granulatum") and combtooth dogfish ("C. nigrum"). The black dogfish is a common species, with a wide but discontinuous distribution in the temperate waters of the Atlantic Ocean; its range abuts, but does not extend into, the Arctic Ocean. In the northeast, it occurs from Iceland to Sierra Leone, including the Faroe Islands, southern Norway, and the Rockall Trough and Porcupine Seabight off Ireland. In the northwest, it is found from southern Greenland and Baffin Island to Virginia, being particularly abundant in the Laurentian Channel, and may occur further south to the
Rockall base. The nearest permanently inhabited settlement is 366.8 km, or 198.1 nmi, west of the headland of Aird an Rùnair, near the crofting township of Hogha Gearraidh on the island of North Uist at . North Uist is part of the "Na h-Eileanan Siar" council area of Scotland. The exact position of Rockall and the size and shape of the Rockall Bank was first charted in 1831 by Captain A. T. E. Vidal, a Royal Navy surveyor. The first scientific expedition to Rockall was led by Miller Christie in 1896 when the Royal Irish Academy sponsored a study of the