Neovison macrodon
sea mink

Although sea mink are now extinct, it once ranged from Casco Bay, Maine in the south to as far north as New Brunswick, Canada. (Manville, 1966; Waters and Ray, 1961)

Skeletal remains of sea mink have been found along the coastal shore of northeastern United States, and probable dens have been found in rocky areas along the north Atlantic ocean front. These findings suggest this species, now extinct, occupied coastal regions. (Manville, 1942; Manville, 1966; Waters and Ray, 1961)

Sea mink were on average 914 mm long, almost twice as long as their close relative Neovison vison, the American mink, which are 580 to 700 mm long. Sea mink tails were on average 254 mm long and the hind foot was on average 88 mm long. When extant, sea mink were commonly mistaken for American mink. However, sea mink remains are distinguishable from those of American mink by a number of different morphometrics including palate length (> 36 mm), length of first molar (> 4.6 mm), width of first molar (> 7.6 mm), humerus length (> 55 mm), and femur length (> 58 mm). Average weight of sea mink is unknown, however male American mink weigh between 0.90 kg to 1.60 kg, and females weigh between 0.70 kg to 1.10 kg. Sea mink skulls were significantly larger than those of American mink, and the carnassials of sea mink were wider and shorter than those of American mink. Sea mink had a dental formula of 3/3, 1/1, 3/3, 1/2 = 34. (Black, et al., 1998; Chapman and Feldhamer, 1982; Manville, 1966; Mead, et al., 2000; Sealfon, 2007)

Sea mink had coarse, reddish dark brown fur. It is unknown whether summer and winter pelages differed, however, closely related species, such as American mink, have winter coats that are much thicker and heaver than their summer coat. Sexual dimorphism, common in nearly all Mustelinae, was also present in sea mink as males were larger than females. (Allen, 1941; Chapman and Feldhamer, 1982; Harris and Yalden, 2008; Mead, et al., 2000)

There is no information available regarding the mating system of Neovison macrodon. Closely related species, such as N. vison, are polygynandrous. Males begin searching for mates in early spring and compete intensely for access to females, which commonly accept multiple mates. (Chapman and Feldhamer, 1982; Harris and Yalden, 2008)

There is no information available regarding the reproductive behavior of Neovison macrodon. The closely related species N. vison mates from February to April. Male-female pairs mate vigorously for an average of 64 minutes. Females exhibit superfecundation (i.e., single litters have more than one father), superfoetation (i.e., single litters include embryos of different ages) and are known to delay implantation. An average litter consists of 4 to 6 kits with gestation lasting between 39 to 76 days. Weaning occurs between 5 to 6 weeks, and American mink are sexually mature at 10 months. (Chapman and Feldhamer, 1982; Corbet and Harris, 1991; Harris and Yalden, 2008; Kurta, 1995; Macdonald and Harrington, 2003; Sundqvist, et al., 1989)

There is no information available regarding parental care in Neovison macrodon. The closely related species N. vison has altrical young. Neovison vison females provide food and protection for the young, which are weaned around 5 to 6 weeks after birth. Neovison vison juveniles disperse around 12 weeks of age. (Harris and Yalden, 2008; Kurta, 1995)

The average lifespan of Neovison macrodon is not known. The closely related Neovison vison has an average lifespan of 6 years in the wild and 10 years in captivity. (Harris and Yalden, 2008; Kurta, 1995)

There is no information available regarding the general behavior of Neovison macrodon. The closely related species N. vison is nocturnal and solitary, only meeting with conspecifics during mating season. It patrols its home range and uses threatening displays during conspecific interactions, including back-arching, piloerection of the tail, tail lashing, stamping and scraping the feet, threat postures, and mouth displays. (Chapman and Feldhamer, 1982; Corbet and Harris, 1991)

The home range of Neovison macrodon is not known. The closely related species N. vison has an average home range of 3 km. Adult male N. vison range between 1,800 m to 5,000 m, juvenile males range between 1,050 m to 1,230 m, and adult females range between 1,000 m to 2,800 m. (Chapman and Feldhamer, 1982; Harris and Yalden, 2008)

There is no information available regarding communication and perception in Neovison macrodon. The closely related species N. vison relies heavily on vision for hunting. Anal scent glands are used to mark territories and are used in conspecific aggression. Vocalizations are also used for communication. (Chapman and Feldhamer, 1982; Corbet and Harris, 1991; Harris and Yalden, 2008; Larivière, 1999)

Sea mink had blunter and wider teeth than do American mink, which is commonly associated with consuming hard-bodied aquatic prey. Evidence of fish remains have been reported in probable den sites, suggesting sea mink mainly fed on aquatic species. Other information on the food habits of sea mink is not available. The closely related species Neovison vison has a seasonal diet that changes throughout the year. (Kurta, 1995; Manville, 1966; Sealfon, 2007)

Aside from humans, major predators of Neovison macrodon are unknown.

No information on the ecosystem roles of Neovison macrodon is available, other than that they were piscivores that occupied coastal regions. The closely related species N. vison is known to carry ticks and fleas, which can be reservoirs for disease. (Corbet and Harris, 1991)

Neovison macrodon were coveted for their fur and possibly meat. Bones have been found at a ceremonial burial site, suggesting N. macrodon may have been consumed during spiritual events. (Black, et al., 1998; Manville, 1942; Waters and Mack, 1962)

There were no known adverse effects of Neovison macrodon on humans.

Sea mink, which were valued for their soft coats, were hunted into extinction during the late 1800s to early 1900s. (Manville, 1966; Turvey and Helgen, 2010)

It has been debated whether Neovison macrodon was a distinct species, rather than a subspecies of N. vison. Neovison macrodon, however, had a larger skull, mandible, humerus, radius, femur, and tibia, and as well as distinctive dental characteristics. (Mead, et al., 2000; Sealfon, 2007)