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(from the name of the mollusk Littorina littorea), a marine basin that existed in the Post-Ice Age (about 7,000–7,500 years ago), occupying the area of what is now the Baltic Sea. It formed as a result of the subsidence of the isthmus in the area of what is now the Denmark Strait and the restoration of the link between Lake Ancylus (which existed before the Littorina Sea) and the ocean. The Littorina Sea covered significant areas of what are now Finland and Sweden, which later rose above sea level as a result of the uplift of the earth’s crust. [14–16734]