Unexpected Discovery: Ancient Fossil Rewrites Evolutionary History of Baleen Whales

A 19-million-year-old fossil jaw bone discovered on the banks of the Murray River in South Australia suggests that the evolution of large baleen whales may have occurred much earlier than previously thought. The fossil, estimated to be from a nine-meter-long baleen whale, challenges the belief that baleen whales remained relatively small until the ice ages. The discovery, along with other fossils from the Southern Hemisphere, indicates that larger baleen whales may have emerged earlier in their evolutionary history. This finding suggests that the Southern Hemisphere played a significant role in the evolution of gigantic whales.