Fullagar et al. (2015) use microwear and residues to argue for seed grinding in the late Pleistocene at Lake Mungo. The ten Zanci/Arumpo grindstone fragments in their study represent only three grindstones when conjoined. Grindstones appear to be rare in these assemblages and are small, hand-sized implements. Traces of starch are low, of uncertain taphonomy and not from known economic taxa. The use-polish may indicate grinding of seeds, but these grindstones were used differently to ethnohistorical seed-grinders. Even if seeds were used, this was probably not a seed-based economy.