Which came first feathers or flying

A.� Assuming that our feathered friends, the birds, descended from dinosaurs, which seems to be the likeliest scenario at present, there has been much debate regarding this question. A recent fossil, a 130 million-year-old Dromaeosaur, provides the best evidence so far that some small flightless dinosaurs developed primitive feathers.

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Since Dromaeosaurs are more primitive than birds, it seems that feathers developed before flight.

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Q.� Is the idea that birds are descended from feathered dinosaurs a new one

A.� No, the evolutionary link was first hit upon by T. H. Huxley, a contemporary of Darwin's, however previous fossils have usually been very fragmentary and open to interpretation. This new fossil contains details so fine that scientists will be able to see how the primitive feathers were attached to the dinosaur's body.

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Q.� Why do scientists think that birds descended from dinosaurs

A.� The crucial piece of evidence is the wishbone shared by both. The wishbone in birds and some dinosaurs is a uniquely fused version of the collarbone, or clavicle, which are still two bones in other vertebrates.

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Q.� What did a Dromaeosaur look like

A.� They were small and looked a bit like Velociraptors, which made an appearance in the film Jurassic Park. They had a sickle-like claw on the middle toe, sharp teeth, and a bone structure similar to that of modern birds.

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Q.� What did the feathers look like

A.� From the fossilised impressions, it seems the primitive feathers comprised of tufts or sprays of filaments. The head and tail were covered with downy fibres, while the arms also seemed to be decked with branched structures similar to the barbs of modern bird feathers.

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Q.� What did feathers evolve from

A.� The long-standing professional consensus is that they evolved from reptilian scales.

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Q.� If the first feathers weren't for flying, why did they evolve

A.� They probably developed first as a means for keeping warm. The smaller and highly active dinosaurs that birds probably descended from may have needed featherlike body coverings to maintain their body temperature.

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Do you have a question about the evolutionary sequence of an animals characteristics Just click here to ask.

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by Lisa Cardy