Dinosaur age fossil snake discovery

This video says about itself:

Lizards, Snakes and Legs (Evolution)

27 September 2008

David Attenborough explaining how lizards lost their legs.

From daily The Independent in Britain:

Ancient snake skull found in Argentina could reveal why the reptiles have no legs

The research challenges the theory that snakes originally became limbless as they began to live in the sea

John von Radowitz

27 November 2015

A fossilised snake skull found in Argentina may have solved the mystery of how the animals lost their legs.

Rather than shed them to become better swimmers as they began to inhabit aquatic environments, the skull, from 90 million years ago, suggests legs became an evolutionary disadvantage as the ancestors of modern snakes wriggled into increasingly narrow burrows in pursuit of prey.

The research challenges the theory that snakes originally became limbless as they began to live in the sea. The secret of the lost limbs was revealed by an examination of the inner ear of Dinilysia patagonica, a two-metre long relative of the modern snake.

Using Computed Tomography (CT), scientists found a distinctive structure in its bony canals and cavities that was also turned out to be present in modern burrowing snakes and lizards.

But the structure, which may assist with the detection of prey and predators, was missing from snakes that live in water or above ground. Lead scientist Dr Hongyu Yi, from the University of Edinburgh’s School of GeoSciences, said: “How snakes lost their legs has been a mystery to scientists but it seems this happened when their ancestors became adept at burrowing.

“The inner ears of fossils can reveal a remarkable amount of information and are very useful when the exterior of fossils are too damaged or too fragile to examine.”

The findings, published in the journal Science Advances, confirm Dinilysia patagonica as the largest burrowing snake ever known.

Co-author Dr Mark Norell, from the American Museum of Natural History, said: “This discovery would not have been possible a decade ago. CT scanning has revolutionised how we can study ancient animals.

“We hope similar studies can shed light on the evolution of more species, including lizards, crocodiles and turtles.”

A CT scan is an advanced form of X-ray that generates detailed 3D images of organs and skeletal structures.

See also here.

Corn snakes, why some are white

This video from the USA says about itself:

15 August 2014

The corn snake (Pantherophis gutattus gutattus) is a medium sized non-venomous colubrid that lives in the southeastern United States. Their bright colors, docile temperament, and minimum care requirements make them great for pets but it’s important to note that those you find in the wild are facing a decline in numbers and should be left alone if at all possible.

From Reptiles magazine:

Corn Snake Genome Sequenced, Albinism Mutation Detailed

November 25, 2015

By John Virata

Scientists with the University of Geneva (UNIGE), Switzerland have sequenced the corn snake Pantherophis guttatus (Elaphe guttata) genome for the first time, and discovered the mutation in the snake that causes albinism in the species, according to a paper published in Scientific Reports.

“Our aim was to produce ourselves a substantial portion of the missing data by sequencing all genes from several reptilian species. To reach this goal, we used tissues, such as the brain and the kidney, expressing the largest number of genes,” said Athanasia Tzika, researcher in the Department of Genetics and Evolution at UNIGE. “The objective was to obtain a genuine reptilian genomic model that people could rely on,” said Athanasia Tzika. “Here, we covered about 85% of the snake total genome size. There is much additional work ahead.”

The data compiled by Tzika will be freely available to researchers around the world who are working on developmental and evolutionary studies of reptiles.

UNIGE researcher Suzanne Saenko, working with Swedish scientists identified the mutation responsible for amenalism. The researchers bred a wild corn snake with a captive bred amenalistic corn snake and DNA sequenced all offspring from the cross and identified the malfunctioning gene. The gene OCA2 codes for a receptor located in the membranes of melanosomes, where melanin is found, according to the study. The receptor controls the acidity that enables the synthesis of melanin.

The researchers say that they will look into how some corn snakes are born with modified colors and patterns like longitudinal lines rather than transversal saddles that are typical of the species.

Smooth snake starts hibernation, video

In autumn, smooth snakes in the Netherlands start their hibernation. Like this individual, near Ede in Gelderland province, crawling into a hole in the ground.

Michael de Vries made this video.

Grass snake swims, video

This video shows a grass snake swimming near Hilversum in the Netherlands on 18 September 2015.

Olga Kuijltjes made this video.

Grass snake’s tongue and eyes, video

This video shows a grass snake in Naardermeer nature reserve in the Netherlands.

It uses its tongue to investigate its environment. As the skin around its eyes is moulting, it is less able to see well for some days.

Joost Majoor made the video.

Naardermeer reconstruction: here.

Adder crawling, video

This video shows an adder crawling between heather plants.

Johann Prescher from the Netherlands made the video.

Adders wintering: here.

Adder research in Hijkerveld, the Netherlands: here.

New death adder species discovery in Australia

This video says about itself:

17 September 2015

A new snake thought to be among the 10 most venomous in the world has been discovered in north-Western Australia. The Kimberley death adder is 50cm long with a pear-shaped head and orange-brown in colour.

From daily The Independent in Britain:

Scientists have discovered a deadly new species of ‘death adder’ in Australia

Doug Bolton

Wednesday 16 September 2015

Scientists have discovered a new type of snake – the comfortingly-named Kimberley death adder – in an isolated region of Western Australia.

The snake was discovered by a group of scientists from the UK and Australia, and measures around 50cm long.

The death adder is already a known species in Australia’s North Territory, and it was believed that the snakes found further west were simply the same species.

However, the group discovered that the snake found in these regions is a different type, unique to that area.

Death adders truly live up to their name. They’re ‘sit and wait’ predators – hanging around waiting for an unlucky animal or human to pass them by, rather than actively hunting on the move.

Their venom is incredibly deadly to humans, and can cause death from total paralysis and respiratory system in around six hours. It is estimated that around 50 per cent of bites from these snakes were fatal before antivenom was introduced.

Despite this fearful bite, the snake is at significant risk from humans, due to habitat destruction and the introduction of new species.

Speaking to The Guardian, Paul Doughty, curator of herpetology at the Western Australian Museum, said it was “a surprise” to find that this death adder was a completely new type.

He also revealed their unsettling hunting techniques – they dangle their tails like a lure, tricking lizards and birds into coming close.

When they’re within striking range, they lash out and kill their prey.

So the next time you’re in Kimberley, Western Australia, and you see something rustling in the undergrowth – run.

See also here.