ABSTRACT
The areas of endemism postulated for the marine triclads are supposed to reflect true endemism instead of relictual endemism. It has been pointed out that marine triclads have a poor dispersal capacity and that the forms one of the reasons for preferring vicariist explanations in the causal analysis of the biogeographic patterns in the Maricola. Transantarctic biogeographic patterns are common among marine triclads and are present in each of the several major taxonomic groups. In case of concordance of branching patterns, the geological plate tectonic events are invoked as causal factors in the explanation of the historical biogeography of the marine triclads. The Maricola also evidence another type of trans-Atlantic track, i.e. one between north and south Atlantic coastal regions. The Procerodidae are also involved in trans-Pacific connections, which result from the biogeographic relationships within the P. lobata-group.
