In the extinction of Australian megafauna blamed climate change

Australian paleontologists have discovered that an extinct local megafauna coexisted with humans for 20 thousand years. It doesn’t sit well with the idea of hunting as the main reason for its extinction. As noted by the authors in their article in Nature Communications, most likely, the ancient giants of Australia became a victim of the gradual desiccation of climate.

In modern Australia there are no large wild animals. Even the greatest representatives of the indigenous fauna, red giant kangaroo (Macropus rufus), weighs less than a hundred pounds. However, it was not always so: a few tens of thousands of years ago the continent Sahul, which included Australia and New Guinea was populated by diverse megafauna that included a large marsupials, flightless birds and hunted some giant reptiles.

The disappearance of the Australian megafauna remains the subject of heated debate among paleontologists. Some believe that the ancient giants disappeared as a result of natural climate change. An alternative point of view lays the blame for the mass extinction of people — the ancestors of Australian aborigines arrived on the continent from Asia about 65 000 years ago. It is assumed that they destroyed large herbivores for meat, which led to the extinction of remaining without prey, predators.

In recent years, most experts are inclined to the second hypothesis. However, the findings of a team of paleontologists led by Scott Hocknull (Scott A. Hocknull) from Queensland Museum, made at the field South Walker Creek (South of Walker Creek) in Central Queensland, show that the pattern of extinction of the Australian megafauna was more complex.

After analyzing the results of the excavations, the authors identified 13 extinct species that qualify for megafauna. These animals formed the community in which the role of large herbivores played a giant relatives of kangaroos and wombats, and the role of predators — marsupial lions (Thylacoleo sp.), land monitor lizards and crocodiles. With them side by side extant the smaller kangaroo and EMU (Dromaius they are a).

The researchers estimated the age of the finds in the 40 — 60 thousand years. If you compare it with an estimated date of arrival of people on the Australian continent, it appears that the megafauna coexisted with the ancestors of the aborigines for the past 20 thousand years. It does not fit into the usual understanding of the rapid extermination of animals people.

The authors note that the time of extinction of the megafauna coincides with the worsening of climatic conditions on the territory of the future of Australia. The process of drying of the continent has increased about 50 thousand years ago and lasted for up to 35 thousand years ago. Following the decline of moisture content changed the composition of plant communities: a vast grassy pastures gave way to dry forests. In addition, increased frequency of fires. All of these factors, according to researchers, made a tough environment for large herbivores and depended on them predators led to their extinction.

The new work provides additional arguments in favor of the fact that man was not the cause of the extinction of the Australian megafauna. However, it is unlikely to put an end to this thread.

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