Sunday 18 September 2011

Feather evolution trapped in Canadian amber

Samples of 80 million-year-old amber in western Canada containing feathers from dinosaurs and birds have yielded the most complete story of feather evolution ever seen. Eleven fragments show the progression from hair-like "filaments" to doubly-branched feathers of modern birds. The find adds to the idea that many dinosaurs sported feathers - some brightly coloured.
Recent years have seen a proliferation of reports about the beginnings of feathers as we know them now in birds. So-called compression fossils found in China bear outlines of primitive "filament" feathers that are more akin to hair. But modern feathers are highly branched and structured, and the full story of how those came to be had not yet been revealed by the fossil record.
Now, a study of amber found near Grassy Lake in Alberta - dating from the Late Cretaceous period - has unearthed a full range of feather structures that demonstrates the progression.

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