SPIRORBID POLYCHAETES AS BOREAL GUESTS IN THE MEDITERRANEAN PLEISTOCENE

Abstract

A first report of Spirorbis spirorbis (Linnaeus, 1758) and Spirorbis corallinae (de Silva & Knight-Jones, 1962) from Early and Middle Pleistocene deposits in Sicily and submerged Late Glacial sediments in the Western Mediterranean is presented. Today both species live on shores and very shallow bottoms in the North Atlantic and are unknown from the Recent Mediterranean. Such differences in their present and past biogeographic distributions suggest that these species were Boreal Guests (BGs) in the Mediterranean Pleistocene. Special attention is paid to tube morphology and structure, which bear some diagnostic features for species identification.