Sydney, Nov 2 (IANS): Ancient species of Australian lizards and snakes, including some of the world's most deadliest, migrated from Asia to the southern continent as early as 30 million years ago, according to a study.

About 85 per cent of the more than 1,000 snake and lizard species in Australia descended from creatures that floated across the ocean, most likely on driftwood, Paul Oliver, the lead researcher of the study conducted by the Australian National University, said on Thursday.

"Around 30 million years ago it appears that the world changed, and subsequently there was an influx of lizard and snakes into Australia," Xinhua news agency quoted Oliver as saying.

The migration was likely spurred by Australia's gradual split from Antarctica.

"We think this is linked to how Australia's rapid movement north, by continental movement standards, has changed ocean currents and global climates."

The study, which included animal data modelling and simulations, helped explain how Australia contains about 11 per cent of the world's 6,300 reptile species, the highest for any country.

The reptiles' migration to Australia was clustered in time, said Oliver.

"The influx of lizards and snakes into Australia corresponds with a time when fossil evidence suggests animal and plant communities underwent major changes across the world," he said.

The study was published in the Nature Ecology and Evolution scientific journal.