Greater scaup refers to a seabird mentioned by Aristotle and others and is thought to refer to a duck, auklet or other seabird. The species name "marila" is from the Greek word for charcoal embers or coal dust. The greater scaup was first studied by Linnaeus in 1761. Male greater scaup from America are distinguishable from those in Europe and Asia by the stronger vermiculations, worm-like carvings or marks on the mantle and scapulars, and are considered a separate subspecies, "A. m. nearctica". Females of the two subspecies are indistinguishable. Based on size differences, a Pleistocene paleosubspecies, "Aythya marila asphaltica", has also
Lesser scaup be recognizable by the purple instead of green sheen of the head and a darker back. But this is unreliable because it varies according to light conditions, and these birds are often too far away from the observer to make out any sheen at all. The best trait—if the primary remiges are not visible—is the shape of the head: in the greater scaup drake, the forehead is usually quite massive, whereas the nape presents a smooth shallow curve and may appear almost straightly sloping. The lesser scaup drake presents the opposite shape, with a less bulging forehead and a nape