Field locality 75-2.
Field locality 75-5.
”Shells collected at clay Andre”

Comments: Arctica is a characteristic North Atlantic genus that ranges from early Cretaceous (Albian) to Holocene and contains only one living species. There are numerous species of Arctica reported in Cenozoic deposits across the North Atlantic margin, but because no critical survey of them has ever been done Arctica species are not especially useful in making age determinations. In Alaska there is one known fossil species, Arctica carteriana (Dall, 1920), known from beds of the Nuwok Member of the Sagavanirktok Formation at Carter Creek, along the coast of the Beaufort Sea about 160 kilometers west of the American-Canadian border. The Nuwok mollusk fauna is thought to be of late Miocene or Pliocene age, though in fact the age is not well documented, and the molluscan taxa show Atlantic affinities. Because the Arctica specimens from Meighen Island are so fragmental they cannot be identified to species, but the Meighen Island species is of about the same size as A. carteriana and much smaller than the living species Arctica islandica (Linnaeus, 1767) that gets up to 12 cm (5 inches) in length. Arctica islandica now lives in the western Atlantic from Cape Hatteras to southern Newfoundland but is abundant only off of Rhode Island, Massachusetts, and Maine. It is not found on Greenland and is abundant on Iceland. In the eastern Atlantic the species is abundant from the southern British Isles and northern France to Norway, and is sparsely present as far north as Murmansk and as far south as the Bay of Cadiz, Spain. This living species is definitely not happy in the high Arctic. According to the literature the coldest water in which living A. islandica has been collected is 0.7 deg. C., and it is said to be unable to live at 0 deg. C., whereas the highest temperature the species is thought to be able to tolerate is “about 19 deg. C.” This species is virtually always found on sand or mud bottoms and seems to have its highest population densities in depths of 10 to 289 meters, although it is reported to live from the intertidal zone to 500 meters.

Arctinula greenlandica is a small pectinid that still lives throughout the Arctic, is abundant off of eastern Greenland and widely distributed throughout the boreal Atlantic, but is missing from the Bering Sea and Pacific Ocean. In the western Atlantic it is found as far south as the Gulf of St. Lawrence and in the eastern Atlantic as far south as Norway. In the western Beaufort Sea Bernard (1979) collected this species in depths of 19 to 2,650 meters. It is reported as a Pleistocene fossil throughout the high North Atlantic and Arctic, although it does not occur in the Pleistocene of Alaska. The only reported fossil occurrence of Arctinula greenlandica in Alaska is at Carter Creek in supposed late Miocene or Pliocene beds of the Nuwok Member of the Sagavanirktok Formation (MacNeil, 1957).

The Nuculana species from Meighen Island is represented by one very small (4 mm long) articulated specimen and several fragments that cannot be identified to species level. However, the one good specimen is identical in shape with, but smaller than, the “?Nuculana sp.” reported by MacNeil (1957) from the Nuwok beds at Carter Creek. No other Nuculana known to me in as close in form to the Meighen Island species as is the Carter creek species, but more specimens from each locality would be needed to make sure that they share the same Nuculana species. The genus is cosmopolitan in distribution although more common in boreal and temperate regions, lives from the intertidal zone to the abyss and ranges from Triassic to Holocene.

My tentative opinion is that the Meighen Island and Carter Creek mollusk faunas represent the same paleoenvironment and are roughly coeval. The presence of abundant Arctica specimens at Meighen Island suggests year-round temperatures above 0 deg. C. The Meighen Island mollusks by themselves are not age diagnostic, but correlation with the Nuwok beds at Carter Creek suggests a possible age of late Miocene or Pliocene. Taking into account the middle or late Miocene Homerian plant fossils from Meighen Island, a quite uncertain “average” age of late Miocene is possible for the Meighen Island beds. Luckily, I made an extensive collection of mollusks in 1978 from the Nuwok beds at Carter creek and one these are studied (later this year) we may know a lot more about the age of this fauna. At any rate, the Meighen Island and Carter Creek mollusk faunas both have Atlantic rather than Pacific affinities.