New dinosaur gives bird wing clue

The Limusaurus fossil sits among small crocodile fossils

A new dinosaur unearthed in western China has shed light on the evolution from dinosaur hands to the wing bones in today's birds.

The fossil, from about 160 million years ago, has been named Limusaurus inextricabilis.

The find contributes to a debate over how an ancestral hand with five digits evolved to one with three in birds.

The work, published in Nature, suggests that the middle three digits, rather than the inside three, remain.

Theropods - the group of dinosaurs ancestral to modern birds and which include the fearsome Tyrannosaurus rex - are known for having hands and feet with just three digits.

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http://news.bbc.co.uk/2/hi/science/nature/8105513.stm