Archaeopteryx has been nudged over into being likely to be pure reptile by a group of Chinese researchers who reported a new find of an Archaeopteryx-like fossil in the 27 July 2011 issue of Nature 475 465-70: An Archaeopteryx-like therapod from China and the origins of Avialae.

Has this new find provided evidence against Darwin's theory? Of course not! And it's interesting to see why not.

Feathers were thought to be absolutely diagnostic of birds; if it has feathers it's a bird and if it doesn't, it isn't. Clear?

Clear until the mid-1990s when some fossil reptiles from China turned up that clearly had feathers; they didn't fly, they may have glided or flapped their way up slopes, but it was soon clear than many of these little dinosaur-like reptiles had feathers. Ooops! Were they on their way to becoming birds? Possibly. But which kind of bird? Some had feathers on front and back legs, some had crests, some had hair-like structures that were feather-like. Some were like Archaeopteryx. Now some have been found that are a lot more like the putative ancestor of birds (Avialae) and it's time for Archaeopteryx to move over. It was the best candidate for the "link" between reptiles and birds, but now a better link has been found and so it's relegated to the mass of reptiles that all had feathers, one of which had descendants that became birds.

The young-Earth creationists will be delighted that "scientists got it wrong" about this fossil which was the most interesting "missing link" for years, and will claim that its demotion "proves" that evolution didn't happen. But this is simply a lovely example of scientists changing their minds when more evidence comes in. So it's not Archaeopteryx, but other feathered reptiles (called Epidexipteryx, Sapeornis and Jeholornis . . . ), and looking much like it, that have usurped the link position -- giving us yet more evidence that birds arose from dinosaur-like reptiles!

(For Lawrence M Witmer's assessment of the finding by Xu et al, read this brief easy-to-read article Palaeontology: An icon knocked from its perch in the same edition of Nature. And yes, I have pinched Witmer's appalling pun for the title of this blogpost.)