Megalania, scientifically known as Varanus priscus, was an extinct giant monitor lizard that once roamed Australia. It was the largest terrestrial lizard known to have existed. Estimates for its size vary, but some studies suggest it could reach lengths of 3.5 to 7 meters (11.5 to 23 feet) and weigh between 97 and 1940 kilograms (214 to 4277 pounds). This reptile was a significant component of Australia’s megafauna.
The Epoch of Megalania
Megalania inhabited the Australian continent primarily during the Pleistocene epoch (2.6 million to 11,700 years ago). Some evidence also indicates its presence during the preceding Pliocene epoch. The youngest fossil remains suggest its existence as recently as 30,000 to 50,000 years ago.
Megalania co-existed with Australia’s diverse megafauna, including giant marsupials like Diprotodon and large kangaroos. Its existence also overlapped with the arrival of the first human populations in Australia, estimated to have reached the continent at least 65,000 years ago. This overlap suggests potential interactions between early human settlers and the giant lizard.
Evidence and Dating
Scientists have pieced together Megalania’s history primarily through its fossilized remains. These finds typically consist of vertebrae, limb bones, and skull fragments, rather than complete skeletons. Such fossils have been unearthed in various locations across eastern and southeastern Australia, including the Darling Downs in Queensland and sites in New South Wales and South Australia.
Determining the age of these fossils involves various scientific methods. Radiometric dating techniques, like uranium-lead dating and radiocarbon dating, are applied to the bones themselves or the geological layers where they are found. Paleomagnetic dating and biostratigraphy, which correlates fossil finds with known faunal assemblages, also contribute to establishing a chronological framework for Megalania’s timeline.
Its World and Disappearance
During Megalania’s time, Australia’s paleoenvironment varied, encompassing open forests, woodlands, and grasslands. The continent experienced significant climatic shifts throughout the Cenozoic Era, with a general trend towards increased aridification beginning in the Miocene and intensifying through the Pliocene and Pleistocene. The Pleistocene was characterized by fluctuating glacial-interglacial cycles, leading to alternating cold, dry periods and warmer, wetter conditions.
The disappearance of Megalania, along with much of Australia’s megafauna, remains a topic of scientific discussion. Theories suggest a combination of factors contributed to its extinction. Climate change, particularly increasing aridity and habitat reduction, likely played a role by affecting its prey populations and overall environment.
Another theory involves the impact of early human populations. This includes potential direct hunting, competition for shared prey, and habitat alteration through practices like fire use. A combination of these environmental pressures and human activities likely led to Megalania’s eventual demise.