Scientists have discovered a 113 million-year-old fossil of a snake which has four legs with fingers and toes.
The Tetrapodophis amplectus – nicknamed ‘huggy snake’ – is the first evidence found of a four-legged snake.
The 20cm-long skeleton, which is thought to be from Brazil, has a tiny head the size of a human fingernail.
It has two very small front legs with wrists, elbows and hands and slightly longer back legs, which would have been used to grasp its prey.
The fossil, which is of a juvenile, also shows adaptations for burrowing, rather than swimming, strengthening the idea that snakes evolved on land.
Dr Dave Martill, who discovered the unseen fossil in a collection in a German museum, said it is “an incredibly significant specimen”.
The University of Portsmouth professor said: “It is generally accepted that snakes evolved from lizards at some point in the distant past.
“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.”
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Dr Martill has been working with expert German palaeontologist Helmut Tischlinger and Dr Nick Longrich, of the University of Bath, who studied the evolutionary relationships of the snake.
Dr Longrich, who had previously worked on the origins of snakes, became intrigued when Dr Martill told him the story at the local pub in Bath.
He said he was initially sceptical, but when Dr Martill showed him photographs, he knew immediately that it was a fossil snake.
He said: “A four-legged snake seemed fantastic and as an evolutionary biologist, just too good to be true.
“It is a perfect little snake, except it has these little arms and legs, and they h
ave these strange long fingers and toes.
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“The hands and feet are very specialised for grasping. So when snakes stopped walking and started slithering, the legs didn’t just become useless little vestiges – they started using them for something else.
“We’re not entirely sure what that would be, but they may have been used for grasping prey, or perhaps mates.”
Interestingly, the fossilised snake also has the remains of its last meal in its intestine, including some fragments of bone.
The prey was probably a salamander, showing that snakes were carnivorous much earlier in evolutionary history than previously believed.