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 more often than those of the greater scaup—particularly during flight—but their call is weaker, a guttural "brrtt, brrtt". Lesser scaup are often hard to distinguish from the greater scaup when direct comparison is not possible, but in North America a large scaup flock will often have both species present. Females, juveniles and drakes in eclipse plumage are hard to identify; there is considerable overlap in length between the two species, but greater scaup are usually noticeably more bulky. Lesser scaup females and immatures tend to have less white around the bill, but this too varies considerably between individual birds. The