At some locations, such as Coral Bay in Western Australia, there is evidence of harvesting of Genyornis eggs.
The shells showed evidence, in the form of point-burning, as occurs when emu eggs were eaten and the shells peeled, some fragments of shell dropping near the fire so that only a protruding point on a piece of shell was burnt.
At some point, apparently a short time after arriving in Australia, the Aboriginal People developed a method of exploiting their food sources sustainably, such as they were known to have practiced with emu eggs at the time of European contact, only taking a few eggs from a clutch, always leaving enough to keep the emu population at a sustainable level.They did the same when harvesting root crops in other parts of the country, always leaving enough tubers to provide another crop for the next harvesting season. The Genyornis and emus had co-existed, usually nesting in the same areas.The emu, having such a wide range of food plants, simply adjusted its eating habits to whatever was available.The fossils of some Diprotodons have been found with the remains of plant material about where their stomach would have been.In the Americas, the megafauna disappeared as humans arrived in Alaska from Siberia, then spread all the way to the southern tip of South America. In these places there are known kill sites, some where large numbers of animals were killed. In Australia there has been very little evidence found of large scale hunting of megafauna.
At Cuddie Springs, a shallow ephemeral lake near Carinda, in semiarid New South Wales, the remains of megafauna animals have been found in association with Aboriginal artefacts and evidence of Aboriginal occupation, hearths and stone tools that still have traces of blood and hair on them.
If it was burnt in a bushfire the whole of the shell would show signs of burning.
But the evidence does not point to large-scale plundering of the eggs.
Comparison of DNA from the bones of megafauna animals and the traces on the stone artefacts shows that they were used to butcher Macropus titan (a giant kangaroo) and Diprotodon.
So at least at this place the Aboriginal People were eating megafauna animals.
Hardwood was widely available in Australia, but the sort of stone necessary for large spear points was not, most of the stone used by the Aboriginal People was stone types such as silcrete, very good for small tools, not so good for large spear points.