A 19 million-year-old whale fossil found on the banks of the Murray River in South Australia is forcing scientists to rethink how and when the world's largest animals, the baleen whales, first evolved their huge size.
It was previously thought that baleen whales evolved their large size about 3 million years ago.
'Researchers at the Museums Victoria Research Institute say this new fossil suggests that larger baleen whales first emerged in the Southern Hemisphere
James Rule is a vertebrate palaeontologist and Research Affiliate at Monash University and worked on this new study, he speaks to Jesse.