Roughly 50,000 years ago, an Australian bird species went extinct, not because of competition for space or resources but because its eggs were simply too delicious.
Australia is a land of giant animals: spiders with foot-long leg spans,bats with six-feet wingspans, lizards reaching up to 200 pounds. The continent has a fascinating history of terrifyingly huge animals.
The flightless bird, known as Genyornis newtoni, was nearly 7 feet tall and appears to have lived in much of Australia prior to the establishment of humans on the continent 50,000 years ago, said CU-Boulder Professor Gifford Miller.
Another line of evidence for early human predation on Genyornis eggs is the presence of ancient, burned eggshells of emus — flightless birds weighing only about 100 pounds and which still exist in Australia today — in the sand dunes. Emu eggshells exhibiting burn patterns similar to Genyornis eggshells first appear on the landscape about 50,000 years ago, signaling they most likely were scorched after humans arrived in Australia, and are found fairly consistently to modern times, Miller said.
More than 85 percent of the continent’s megafauna went extinct not long after humans arrived.
The reasons for these extinctions are hotly debated. Some scientists say humans are to blame, others credit climate change and some say it’s likely a mixture of both.
But the continental drying of Australia, from about 60,000 to 40,000 years ago, is likely not the main reason for these animals’ extinctions, Miller said. The rate and magnitude of this climate change was as severe as earlier climate shifts, but large megafauna extinctions did not accompany these earlier changes, he said.
“Ours is the first study to show with direct evidence that early humans in Australia also preyed on the now-extinct megafauna,” he told Live Science.