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Not dinosaurs, but still interesting...



Earliest salamanders discovered 
By Jonathan Amos 
BBC News Online science staff 

Scientists have discovered the earliest examples of salamanders - specimens up
to 165 million years old - in fossil beds in Mongolia and China. 

Scientists say they have found literally thousands of the animals preserved in
volcanic ash. 
The researchers describe one juvenile in particular that reveals the amphibian's
eye, folds in its tail and a stomach bulging with clams. 

The discoveries are part of an ongoing excavation programme being conducted by
staff from the University of Chicago, US, and Peking University in Beijing,
China. 

Before these extraordinary finds, the oldest known salamander fossils dated back
only to the Tertiary Period, which began 65 million years ago. 

Life cycle 

"What excites us is that we're not only seeing the earliest known salamanders in
the fossil record, but we've thousands of them," Professor Neil Shubin told BBC
News Online. 

"There are whole bodies, impressions of soft tissue preserved, and stomach
contents. It's really unusual that you have such a view of the early evolution
of a group of animals like this." 


In the journal Nature this week, the scientists describe in detail an amphibian
they call Chunerpeton tianyiensis . 
It is said to resemble the North American hellbender, a common salamander
currently found in Asia, as well as in the Allegheny Mountains near Pittsburgh
in the US state of Pennsylvania. 

The bones in the front of its skull, its fingers, toes and ribs are all somewhat
different, however. 

Other complete fossils, including some with those rare soft tissue impressions,
offer a wealth of new information on the salamander's origin and life cycle. 

Modern distribution 

"You have tiny guys who might be just a millimetre long right up to adults that
might be 20 centimetres long. It's remarkable," said Shubin, who is professor
and chairman of organismal biology and anatomy at the University of Chicago. 

"Some of the adults look like big larvae; some of them have retained their
larval features as adults. And we have some that have clearly metamorphosed. 


"The exquisite condition of these fossils offers clues to evolutionary
strategies - larval details such as gills in adult animals, for example." 
The finds confirm, in Shubin's and colleague Ke-Qin Gao's view, that salamanders
originated in Asia. 

"About 200 million years ago, the world had one supercontinent, [Pangea]. Then
the continents began to split apart - the big split being between a northern
landmass called Laurasia and a southern landmass called Gondwana. 

"Gondwana has Africa, South America, Australia, Antarctica. Laurasia has North
America, Europe and northern Asia. It seems salamanders evolved around this
split so that today they are almost entirely Laurasian in distribution. 

"The creatures we are finding in China are relatives of the salamanders in Asia
and North America today." 

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/2896407.stm