Snake fossils up to 25 million years old unearthed in north-west Queensland strongly suggest snakes evolved from lizards, says Palaeontologist John Scanlon.Scanlon said the bones in the jaws and faces of the two large snakes, which were well preserved in limestone in the Riversleigh world heritage area near Mount Isa, were closer to those of lizards than modern snakes.
The two snakes were part of the Madtsoiid branch of the snake family that "split off" about 95 million years ago, said Dr Scanlon, who works at the Riversleigh Fossils Centre at Mount Isa. "The way the upper jaws are connected to the brain case and the structure of the ear region ... supports their origin from goanna-like lizards."
He said the snakes, which were almost five and six metres long, were part of a species that died out in Australia about 50,000 years ago. "They died out about 40 million years ago outside of Australia but because the country is isolated, it became like this lost world," Dr Scanlon said.
He said the Madtsoiid snakes were not venomous and are not closely related to any modern species of snakes.