Barnacles are a delicacy in some parts of the world, but are seldom recognized as a potential food source by English-speaking archaeologists. Pollicipes pollicipes, a species of peduncular barnacle, is widely eaten along the Atlantic coast of Europe today, and is also common in some archaeological sites in the region. Recognizing and properly recording this barnacle can deepen our understanding of prehistoric coastal adaptations in Europe and other parts of the world where related species are found. With an example from the Neolithic site of Rocha das Gaivotas, Portugal, this article explores the potential usefulness of barnacle remains in answering larger questions about the context of social and economic change in southwestern Europe.