After finding ancient fossils of a giant, deadly lizards in Australia, researchers have concluded that their existence overlapped with the arrival of early humans to the land down under. But this relationship was not a harmonious one.

"Our jaws dropped when we found a tiny fossil from a giant lizard during a two-meter-deep excavation in one of the Capricorn Caves, near Rockhampton," Dr. Gilbert Price, a vertebrate paleontologist from the University of Queensland, said in a news release. "The one-centimeter bone, an osteoderm, came from under the lizard's skin and is the youngest record of a giant lizard on the entire continent."

Osteoderms are bony deposits found on the skin of many reptiles. The sample was excavated from a fossil-rich site in the Capricorn Caves in Australia. Researchers dated them to around 50,000 years ago – which means it was alive during the last Ice Age. During this time, other massive lizards and inland crocodiles nine meters long also roamed Australia, making life difficult for early humans. Modern lizards only grow to about two meters long.

"We can't tell if the bone is from a Komodo dragon -- which once roamed Australia -- or an even bigger species like the extinct Megalania monitor lizard, which weighed about 500kg and grew up to six meters long," Dr. Price added. "The find is pretty significant, especially for the timeframe that it dates."

While the extinction of large lizards and megafauna from this time period has long been debated, researchers noted the findings suggest humans are now only considered a potential contributor to the demise of these reptiles.

"This study also begs the question -- what else is entombed in our caves and what else can we learn?" asks Ann Augusteyn, Capricorn Cave manager,  

The findings were recently published in the journal Quaternary Science Reviews.

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