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
Greater scaup 100% of female greater scaup, and 77% of female lesser scaup, had escalated levels of selenium in their bodies. Selenium is an occurring semimetallic trace element that occurs naturally in some soils and minute amounts are necessary for animal life. However excessive selenium can cause reproductive harm and is highly toxic. On their migration across the Great Lakes, greater scaups are at risk of ingesting selenium by eating the invasive zebra mussels, which can render a hen infertile. This sterilization of hens is causing the population to decrease. In a study of 107 scaup, they all had traces of iron,