The last time one of these near-mythical beasts was spotted in western Europe was in 1949 (the same year the Polaroid camera first came to market). The animal’s skeleton will be moved to the Royal Belgian Institute of Natural Sciences, where it will join the collections as an important natural history specimen.

“This sighting is particularly significant as in the past 14 months we’ve had other Arctic cetaceans visit our waters,” explains Dr Peter Evans, founder of the Sea Watch Foundation, an organisation that works to monitor whales, dolphins and porpoises in the area. “Sea temperatures were unusually low last spring, and [there’s] a possibility that the fragmentation of floating ice may have resulted in whales typically associated with pack ice straying much further south.” One such animal was a beluga whale, the only other species in the family Monodontidae, to which narwhals also belong.

Narwhals (Monodon monoceros) are known to travel in groups of 15 to 20 individuals, so there is some concern among scientists that this carcass won’t be the only one to surface. However, the topology of the North Sea has been known to function as a “whale trap” under certain conditions, and it’s entirely possible that this animal was separated from its pod.

The swirling tusk that gives these pale-coloured porpoises their species name (monoceros is Greek for “unicorn”) is found only in males. The tusk is a modified tooth – the front left canine – which breaks straight through the upper lip as it grows. While the tusk certainly can be used for sparring, researchers have found that nerve endings within it could allow narwhals to “taste” surrounding waters.

Unlike most mammal teeth, narwhal tusks are not protected by enamel. They contain a system of channels and tubes that usher in traces of sea water, which, once inside, excite nerves at the centre of the tooth. It’s thought that this interaction alerts the animal’s brain to any chemical or temperature changes in its environment – a particularly handy trick when searching for food or a mate in the vast Arctic seas.

Though the Belgium narwhal was already in an advanced state of decomposition by the time it was discovered, a necrospy (animal autopsy) has been performed. Determining a cause of death from this state can be tricky, but we’ll be updating you as any information comes to light.