Abstract
Over millions of years, plate tectonics, palaeoceanography and the
resulting changes in the global climate (greenhouse to icehouse) have
impacted the Southern Ocean marine fauna and flora, caused evolutionary
extinctions and radiation of benthic marine invertebrates, and led to
the present biodiversity. Simultaneous biogeographical events happening
were the progressive retraction of cosmopolitan taxa established during
the Jurassic and Cretaceous periods when Antarctica was still under
greenhouse conditions. The disjunctive distribution patterns resulted
from vicariance due to the disintegration of the supercontinent
Gondwana. Active migration of taxa in and out of the SO (depending on
dispersal capabilities) caused a change in biodiversity composition of
several invertebrate taxa over geological time scales including the
period after the geomorphological isolation established. It is assumed
that life on the seabed has not been completely erased at any time in
the geologic past, although some taxa vanished while others thrived or
radiated. Nowadays, natural and anthropogenically driven climate change
processes shape the Southern Ocean marine fauna and we can only
anticipate the threat associated with these changes because the
processes driving speciation as well as biodiversity changes are not
fully understood yet. Images
