Cryoturris aptera  Cryoturris aptera is an extinct species of sea snail, a marine gastropod mollusk in the family Mangeliidae. The length of the shell attains 11.4 mm, its diameter 3.9 mm. This extinct marine species has been found in Pliocene strata of the Bowden Formation, Jamaica; age range: 3.6 to 2.588 Ma.