Megafauna or giant animals inhabited Australia 50,000 to 60,000 years ago. Animals, such as mammoths, crocodile-sized lizards, and 1,000-pound kangaroos roamed the rainforest of that continent. However, they became extinct and scientists have different theories as to why they were suddenly wiped out. The most prevalent theory about the extinction is climate change. However, a recent research suggests that it was caused by humans rather than by nature.

The team that conducted the research were scientists from the Monash University in Victoria, Australia and the University of Colorado Boulder. They said that the collapse of the megafauna population is relative to the arrival of humans in the area.

The scientists based their conclusion on the information they gathered from the drilled sediment core in the Indian Ocean just off the southwest coast of Australia. The core consists of layers of materials which was carried into the sea from land. One of these materials is the Sporormiella, a species of fungal spores which grew in the dung of herbivores. The scientists say that the abundance of these meant there were also a a big animal population in the are but it dwindled over time.

Aside from that, the sediment they had studied from the area suggests that it is a land where biodiversity could have thrived. Moreover, the material does not hold any clue that there was indeed a climate change that occurred in the area as previously suggested by earlier research.

So what did humans do that totally wiped out this great megafauna population?

There are several studies and theories by other scientists as to how humans brought these animals to extinction. Gifford Miller, professor at the Colorado University and also part of the research team, had an earlier study in 2016 which suggested that humans overhunted and overkilled animals. One example, he said was humans gathering and cooking the eggs of 7-foot giant birds called Genyornis newtoni.

In another study conducted by Gavin Prideaux, a paleontologist at Flinders University, said that aside from hunting, humans destroyed the landscape through burning which destroyed the animal habitat and induced a change in climate. The human-induced climate change dramatically changed the food web and plant diversity of the area. With the ecological balance destroyed, the megafauna also decreased and eventually became extinct.