"We are talking about huge, brick-sized molars here – the largest of any animal, but the signs of tooth wear are tiny, down to thousandths of a millimeter. However, these microscopic surface textures can tell us whether they were eating grass or leaves," said team member Zhang Hanwen, from the University of Bristol, UK.
By comparing the results with information from modern ruminants (deer, antelopes and oxen) of known diet, the study concluded two extinct elephant genera from southern China – Sinomastodon and Stegodon – were primarily browsing on leaves.
The third, Elephas, which includes the modern Asian elephants, shows much more catholic feeding habit, incorporating both grazing and browsing.
"It's wonderful that we can identify diets of any fossil mammal with confidence now," said team member Prof. Christine Janis, also from the University of Bristol…"