This is an egg capsule from the Norwegian Sea Snail, also known as the Norwegian Volute (Volutopsius Norwegicus). This specific example shows a beautifully adapted capsule that the sea snail uses to protect and nourish its young. Found in the cold, deep waters of the northeastern Atlantic, particularly near Norway, these snails lay solitary egg capsules that attach firmly to hard surfaces like the insides of old bivalve shells.

These eggs are laid in thick, horny capsules—a tough, resilient material—shaped like a slightly flattened lens and about one inch in diameter. The capsule’s surface would have originally been a pale yellow or dirty lemon colour, with a thin white coating that gradually breaks into fine, crystalline particles, giving it a faintly rough, corrugated texture. However, this egg capsule appears to have darkened due to oxidation. The underside is smooth and satiny, giving the capsule added strength and adherence. This tough exterior is essential for survival in the snail’s deep-sea habitat, where the capsule must withstand varying conditions at depths of 100 to 600 metres.

Inside the capsule, the developing eggs would have been a bright pink or flesh colour. Each capsule holds 2 to 4 young sea snails, known as “fry,” that eventually exit through a small slit in the capsule’s rim. These capsules have also been observed in other locations, including East Greenland, though with slight variations in colour and texture. The development within these capsules allows young snails to emerge ready for life on the seafloor, where they contribute to the benthic ecosystem by preying on smaller invertebrates.