Fig. 1.6.

Sea level changes and land exposure. A, Approximate sea level changes from the Jurassic period to the present (reading downwards; E-early, M-middle, L-late), with indications of current sea level; B, Low sea level exposed the landmass, termed Sahul, that included Australia and all its northern islands and Papua New Guinea and far extended the coastline towards modern Indonesia. The dark shading in B refers to the range of the black butcherbird and the arrows (both ways from and to Sunda) suggesting that, at certain times in the past, moving in and out of Sahul/Australia often required no more than island hopping.