Biogeography of Southern polar bryozoans

Despite the central role of Antarctica in the history and dynamics of ocean ography in mid to high latitudes of the southern hemisphere there remains a paucity of biogeographic investigation. Substantial monographs over the la st century coupled with major recent revisions have removed many obstacles to modern evaluation of many taxa. Bryozoans, being particularly abundant a nd speciose in the Southern Ocean, have many useful traits for investigatin g biogeographic patterns in the southern polar region. They fossilise well, transitory morpho-stages between species are brief and most bryozoans have reduced dispersal opportunities due to possession of benthic larvae. Furth er to previously described broad faunistic patterns we demonstrate that bry ozoans show sub-patterns within the Polar Frontal Zone. Four bryozoogeograp hical zones are recognised in Antarctica waters: East Antarctic seas, West Antarctic seas, the Antarctic Peninsula and the Scotia Are. We discuss diff erences between species, genus and family level patterns in three marine or ders (of differing geological age) and factors responsible for creation of such distributions.