Sediment samples were taken along the Cantabric platform (Northern Spain) from 200 to 600 meters depth in October 1990. Forty specimens of loriciferans were sorted out of the samples, of which 38 specimens belong to a new species of Rugiloricus. The new species, R. manuelae sp. nov., was investigated with both light (DIC) and electron microscopy (SEM). Complete descriptions of both adult and larval stages are provided, including mapping of the introvert scalids for both stages. Information from a molting stage with an adult male inside confirms conspecificity of larvae and adults. The presence of a highly reduced postlarval stage leaded to the suggestion of a new modified life cycle for the family Pliciloricidae.