CENOZOIC BIODIVERSITY 155Fig. 1. The physical isolation of Antarctica. Late Eocene and Middle Miocene south polar projections redrawn
and simplified from Lazarus & Caulet (1993, figs 19 and 22), with some additional detail from maps contained
in Lawyer el al. (1992). Key: stipple, continents; grey shading, continental shelf; arrows, principal current
directions.