Most people think of lizards as nothing more than pets to be kept in cages, or small animals that scurry around eating insects. A few lizards, however, like the komodo dragon, are truly beasts and could potentially kill humans. One lizard that used to live in Australia, however, was dragon-sized in its proportions, measures as long as 15 feet, and now scientists believe that it may have lived alongside humans.
Scientists have long known that huge lizards prowled the Australian outback, but many believed that these behemoth beasts died out before humans settled in the “Land Down Under”. A recent discovery of a giant lizard bone in a cave, however, suggests that the giant lizards may have still been alive when humans arrived.
Researchers found an osteoderm, a tiny bon found underneath the skin of lizards and were able to date the bone using radiocarbon and uranium-thorium techniques. They concluded that the bone was about 50,000 years old, and that it came from a giant lizard. Scientists aren’t yet sure what species of lizard the bone came from, but one theory being floated around is that it was the Megalania Prisca, which could measure up to 15 feet in length. It is believed that these lizards were able to hunt and kill large mammals.
Instead of man-eating lizards, some scientists believe that the reverse may have been true. It may have been the arrival of humans that drove the giant lizards into extinction. Armed with primitive weapons and able to hunt in highly coordinated groups, the early humans of Australia would have likely been able to overpower and kill the giant lizards, if they were indeed present.
The largest lizard to still live in Australia is a monitor lizard called the perentie. This lizard can measure about six feet in length, but is rather slender. The lizards are known for avoiding human contact, and for retreating when confronted by humans. They dine on smaller animals, such as rats and rabbits.
It’s possible that the fossil discovered was from a komodo dragon, which can measure about 3 meters (10 feet) in length. Komodo dragons are currently only found on a small number of islands in Indonesia, but it’s possible that they were once found on more islands. Many researchers believe that the lizards grew so large because of island gigantism. Isolated on the smaller ecosystems of islands, some animals grow unusually large. Komodo dragons are suspected of occasionally attacking and consuming humans, though such attack are rare, if they do indeed happen.
Australia is known for its giant massive animals, a phenomenon called Australian megafauna. These megafauna are defined by having a body mass bigger than 45 kilograms, or at least being 30 percent larger than their modern predecessors. The animals are epic in proportion, to say the least. One animal, the diprotodon weighed nearly 3,000 kilograms and resembled a giant wombat. The Procoptodon was a kangaroo that stood nearly 7 feet tall and weighed over 200 kilograms.
Ancient humans, as slight as they may have been, are considered by many to be the likely cause of decline for many of these oversized animals.