Science , NUMBER@1 NUMBER@2 PMID NUMBER@3 Increased aridity during peak glaciation -LRB- about NUMBER@4 years ago -RRB- may have also contributed to the extinction of the megafauna .

Science , NUMBER@1 NUMBER@2 PMID NUMBER@3 Climate change , which made the country much drier during an Ice Age about NUMBER@4 years ago , may have also have led to the extinction of the megafauna .
