Daily BulletinDaily Bulletin

The Conversation

  • Written by The Conversation
imageSnake ancestor was crawly as well as creepy.Dave Martill, University of Portsmouth

How did the snake get its slither? Ever since the crafty serpent in Genesis tempted Eve into eating the forbidden fruit, we’ve been fascinated by snakes. And, despite our interest in this animal, we have a poor understanding of how it actually evolved. But scientists have now released a new study on the fossil of a snake that appears to have lived between 100m and 146m years ago. And what’s more it had legs.

The reasons we know so little about snake evolution is because there are so few fossils. Molecular data suggests that snakes appeared within the squamate family tree – including lizards and amphibians without limbs – sometime in the Jurassic (more than 150m years ago). However, the oldest known undisputed fossil snakes are much younger, from the Cretaceous (about 110m years ago).

imageThe worm-like slender glass lizard.Dawson/wikimedia, CC BY-SA

While snakes are thought to be a single evolutionary group, sharing a common ancestor, the evolution of limblessness is actually quite a common feature of squamate evolution. The loss of limbs, correlated with body elongation, has occurred during the evolution of more than 20 members of this group of vertebrates. An example are the flap-footed lizards called Pygopodidae, which look very similar to snakes.

Perhaps there is a biomechanical reason for this kind of evolution? If the body evolves to get longer and longer, it may be physically harder to effectively use legs and arms. In the case of snakes, some fossils are known that document one part of this transition, showing that, earlier in their evolution, some snakes had hindlimbs. This has also led to suggestions that these squamates evolved from animals in the oceans.

A body for burrowing

But the new fossil, Tetrapodophis, from Brazil, has four intact limbs and a super-elongate body – similar to modern snakes. Interestingly it also has many more vertebrae than is normal for any snake known so far, living or fossil.

imageWell preserved specimen.Dave Martill, University of Portsmouth.

This fossil suggests that this body structure would work for burrowing rather than swimming. That’s one reason why it is so important – it implies that snakes evolved on land rather than in the sea.

Aside from being critical to new understanding of the early evolution of snakes, this fossil is also interesting in a wider palaeontological context.

As I have argued previously argued, fossil collecting is a field in which anyone can, and should, be encouraged to participate. Fossils housed in all kinds of collections should form the basis of our scientific work.

imageArtist’s impresion of the four-legged snake.Julius T Cstonyi

Many people, including some professional societies, argue that only fossils curated and reposited in recognised public institutions (such as museums and universities) should be worked on and appear in scientific journals.

According to this paper, the snake fossil specimen is part of a private collection, where it was housed for many decades before its importance was realised. The owner has now placed it in the long-term care of the Bürgermeister-Müller-Museum in Germany. However, many of us working in the field are hoping that it will be returned to Brazil in the near future.

Gareth Dyke receives funding from National Geographic and the University of Southampton.

Authors: The Conversation

Read more http://theconversation.com/fossil-from-brazil-sheds-light-on-how-snakes-lost-their-legs-45170

Low-paid, young women: the grim truth about who this recession is hitting hardest

arrow_forward

Vale Ennio Morricone: a master composer with breathtaking musical range

arrow_forward

The Conversation
INTERWEBS DIGITAL AGENCY

Politics

Prime Minister Interview with Ben Fordham, 2GB

FORDHAM: Thank you very much for talking to us. I know it's a difficult day for all of those Qantas workers. Look, they want to know in the short term, are you going to extend JobKeeper?   PRI...

Scott Morrison - avatar Scott Morrison

Prime Minister Scott Morrison interview with Neil Mitchell

NEIL MITCHELL: Prime minister, good morning.    PRIME MINISTER: Good morning, how are you?   MICHELL: I’m okay, a bit to get to I apologise, we haven't spoken for a while and I want to get t...

Scott Morrison - avatar Scott Morrison

Prime Minister Interview with Ben Fordham

PRIME MINISTER: I've always found that this issue on funerals has been the hardest decision that was taken and the most heartbreaking and of all the letters and, you know, there's been over 100...

Scott Morrison - avatar Scott Morrison

Business News

SEO In A Time of COVID-19: A Life-Saver

The coronavirus pandemic has brought about a lot of uncertainty for everyone across the world. It has had one of the most devastating impacts on the day-to-day lives of many including business o...

a Guest Writer - avatar a Guest Writer

5 Ways Risk Management Software Can Help Your Business

No business is averse to risks. Nobody can predict the future or even plan what direction a business is going to take with 100% accuracy. For this reason, to avoid issues or minimise risks, some for...

News Company - avatar News Company

5 Ways To Deal With Unemployment and Get Back Into the Workforce

Being unemployed has a number of challenges and they’re not all financial. It can affect you psychologically and sometimes it can be difficult to dig your way out of a rut when you don’t have a job ...

News Company - avatar News Company



News Company Media Core

Content & Technology Connecting Global Audiences

More Information - Less Opinion