behind the eye sockets). In fact, the most notable characteristic of the skull was its size, in that it was clearly larger than that of other mink species, having a wide rostrum, large nostril openings, large antorbital fenestrae (openings in the skull in front of the eye socket), and large teeth. Their large size was probably in response to their coastal environment, as the largest extant subspecies of American mink, the Alaskan mink (N. v. nesolestes), inhabits the Alexander Archipelago in Alaska, an area with a habitat similar to the Gulf of Maine. Mead, concluding that the mink was restricted to nearshore islands, suggested that the large size was due to insular gigantism. Since almost all members of the subfamily Mustelinae exhibit sexual dimorphism, male sea minks were probably larger than female sea minks. The sea mink's wider carnassial teeth and blunter carnassial blades suggest that they crushed hard shells more often than did the teeth of the American mink. Behavior Although not a truly marine species, being confined to coastal waters, the sea mink was unusually aquatic compared to other members of Musteloidea, being, next to otters, the most aquatic member of the taxon. As marine mammal species often play a large part in their ecosystems, the sea mink could have been an important intertidal predator. It may have had a similar diet to the American mink, consuming seabirds, seabird eggs, and hard-bodied marine invertebrates, though in greater proportions. Its seafood-oriented diet may have increased its size. Remains of toad sculpins and ocean pout were the most common around their dens, and garden banded snails were also reported to have been part of their diet. According to fur traders, the sea mink was nocturnal and resided in caves and rock crevices during the day. It reportedly made a den with two entrances in the rocks piled up by the waves. Like other minks, individual sea minks may have maintained home ranges, and since the males were larger and required more food, males would have had larger territorial claims. Likewise, their larger size may have allowed the males to target larger prey than the females, and they may have had to defend females during mating seasons. Like other weasels, the sea mink was probably polygynandrous, with both sexes mating with multiple individuals. Due to the overlap of American mink and sea mink ranges, it is possible that they hybridized with