The discovery of what's thought to be the first four-legged snake fossil is giving scientists a closer look at how the slithery creatures evolved from lizards.
The unusual remains, 20 centimeters long with tiny 1-centimeter legs, were reported by researchers at England's University of Portsmouth in the journal Science on Thursday, and are estimated to be about 110 million years old.
"It really is a fantastic, very very rare and extremely important fossil for evolutionary studies," the study's lead scientist, Dave Martill, said in a video released by the university.
Martill said his team hopes the fossil, the oldest definitive snake discovery, will finally reveal the story of how some lizards lost their legs.
“It is generally accepted that snakes evolved from lizards at some point in the distant past," Martill said in a press release. "What scientists don’t know yet is when they evolved, why they evolved, and what type of lizard they evolved from. This fossil answers some very important questions, for example it now seems clear to us that snakes evolved from burrowing lizards, not from marine lizards.”
Martill said the fossil is considered a snake, not a lizard, because of its elongated body; a skull, jaw, vertebrae and impression of scales resembling a snake's; and the bony remains of its last meal fitting the diet of a snake.
The fossil was excavated in Brazil decades ago and had been sitting untouched in a private collection until Martill came across it and began studying it, the journal Nature reported.
Other scientists weren't as quick to accept Martill's conclusion.
“I think the specimen is important, but I do not know what it is,” biological scientist Michael Caldwell of the University of Alberta told National Geographic. “I might be wrong, but that will require me to see the specimen first hand. I’m looking forward to visiting Solnhofen,” the museum in Germany where the specimen is housed.