When sea levels fell during the Pleistocene ice age, including the last glacial maximum about 18,000 years ago, the Sahul Shelf was exposed as dry land. Evidence of the shoreline of this time has been identified in locations which now lie 100 to 140 metres below sea level. A useful interactive timeline of sea level changes has been developed by Monash University. The Arafura Shelf formed a land bridge between Australia, New Guinea and the Aru Islands and these lands share many marsupial mammals, land birds and freshwater fish as a result. Lydekker's Line, a biogeographical line, runs along the edge of Sahul Shelf where it drops off into the deep waters of the Wallacea biogeographical area. Wallacea sits in a gap between the Sahul Shelf and the Sunda Shelf, part of the continental shelf of Southeast Asia.
The name "Sahull" or "Sahoel" appeared on 17th century Dutch maps applied to a submerged sandbank between Australia and Timor. On his 1803 map, Matthew Flinders noted the "Great Sahul Shoal" where Malays came from Makassar to fish for trepang (sea cucumber).
The existence of the much larger Sahul Shelf was suggested in 1845 by G.W. Earl who called it the "Great Australian Bank" and noted that macropods ("kangaroos") were found on Australia, New Guinea and the Aru Islands. Earl also suggested the existence of the Sunda Shelf which he called the "Great Asiatic Bank". The Sahul and Sunda shelves were given their present names by G.A.F. Molengraaff and W. Weber in 1919.