Dragons may come from the land Down Under.
Scientists now find that the world’s largest living lizard species, the Komodo dragon, most likely evolved in Australia and dispersed westward to its current home in Indonesia.
In the past, researchers had suggested the Komodo dragon (Varanus komodoensis) developed from a smaller ancestor isolated on the Indonesian islands, evolving its large size as a response to lack of competition from other predators or as a specialist hunter of pygmy elephants known as Stegodon.
However, over the past three years, an international team of scientists unearthed numerous fossils from eastern Australia dated from 300,000 years ago to roughly 4 million years ago that they now know belong to the Komodo dragon.
“When we compared these fossils to the bones of present-day Komodo dragons, they were identical,” said researcher Scott Hocknull, a vertebrate paleontologist at the Queensland Museum in Australia.
For the last 4 million years, Australia has been home to the world’s largest lizards, including the 16-foot-long giant (5 meters) called Megalania, once the world’s largest terrestrial lizard but which died out some 40,000 years ago.
“Now we can say Australia was also the birthplace of the three-meter (10 foot) Komodo dragon,” Hocknull said.
The researchers said the ancestor of the Komodo dragon most likely evolved in Australia and spread westward, reaching the Indonesian island of Flores by 900,000 years ago. Comparisons between fossils and living Komodo dragons on Flores show that the lizard’s body size has remained relatively stable since then.
Further support for this notion of dispersal from Australia comes from the island of Timor, located between Australia and Flores. Three fossil specimens from Timor represent a new, as yet unnamed species of giant monitor lizard, which was larger than the Komodo dragon, although smaller than Megalania. More specimens of this new giant lizard are needed before the species can be formally described.
“There are a lot of things we just simply don’t know about this part of the world – Indonesia to Australia,” Hocknull told LiveScience. “In recent years this region has thrown up remarkable discoveries – a new species of hominid, the ‘Lost World’ in New Guinea boasting dozens of new species having never met humans, and now an island chain of giant lizards, including the largest of them all, Megalania from Australia. However, they all went extinct, except the Komodo dragon. The big question now is why? …
via Origin of Komodo Dragon Revealed – Yahoo! News.