About a month ago, there was big publicity about the discovery and description of a new fossil bird from China, Xiaotingia zhengi. It is one of a long line of amazingly preserved bird fossils that have come from Jurassic and Cretaceous beds in Liaoning and other areas in China, and have completely revolutionized our understanding of early bird evolution. Where we once had only the few specimens of Archaeopteryx and a handful of isolated bones from other regions, now we have hundreds of beautifully preserved specimens which are completely articulated with their feather impressions and sometimes even evidence of coloration and stomach contents. Even more surprising, these fossils show not only the stages in bird evolution after Archaeopteryx, but also demonstrate that many non-avian dinosaurs more primitive than Archaeopteryx had feathers as well. In fact, some of these fossils are so clearly rooted in the base of the theropod family tree that it’s reasonable to assume that all predatory dinosaurs had some kinds of feathers (including T. rex, Velociraptor, and other popular favorites), although some may have lost them in large adults. Furthermore, some specimens have been found to suggest that feathers were widespread among all dinosaurs, including the ornithischian branch (herbivorous dinosaurs like the horned dinosaurs, duckbills, stegosaurs, etc.).
Xiaotingia is particularly interesting in that it comes from Upper Jurassic beds in China, making it nearly contemporaneous with Archaeopteryx and much earlier than most Chinese birds that come from the Cretaceous. It is more primitive than Cretaceous birds, exactly as predicted by evolution. More importantly, it shows a suite of features that make it a very close relative of Archaeopteryx, and (according to Xu et al., 2011), make both creatures more primitive than the bona fide birds in the group Avialae. Xu et al. suggest that they are closer to their dinosaurian ancestors, the dromaeosaurs, than they are to more advanced birds (see figure).
The announcement was hailed as important by many paleontologists, and added to the many other important discoveries that were made this year. All this new discovery claims is that Xu et al. (2011) suggest switching Archaeopteryx from within the pigeonhole we call birds (Avialae) to the next nearest pigeonhole, the bird-like dromaeosaurs. It’s just a tiny shift in classification, not an earth-shaking debunking of bird evolution. Such a conclusion is very tentative (as the authors suggest), and needs to be evaluated when others study the same specimens, but it is intriguing. But count on the creationists to read just the brief summary of the article and completely misinterpret every bit of it.
P.Z. Myers and others have summarized the falsehoods that the creationists have said about the fossil, and rebutted most of the major misconceptions. But a few clarifications are in order here, since I discussed the transition from dinosaurs to birds in my book Evolution: What the Fossils Say and Why it Matters, and many of the subtleties are lost on non-paleontologists.
World Net Daily, the right-wing fundamentalist birther site, published a screed by David Menton and Ken Ham that was breathtaking in its stubbornness and stupidity. Somehow they cherry-pick little bits and pieces of the bird-dinosaur evolutionary story and get everything ass-backwards. Ham writes: “Archaeopteryx is just a bird.” This is a lie is the one creationists have always used, and I debunked in my 2007 book: “Archaeopteryx had feathers, therefore it is a bird”—end of story. They never mention all the dinosaurian features of its skeleton (teeth, skull, unfused sacrum, bony tail, dinosaurian hand and foot, etc.). Nor do they comment on all the new evidence that most dinosaurs had feathers, too. They also write, “This and other since-discredited assumptions about evolutionary process still are being taught as fact in schools.” Regarding this point, nothing about the new specimen changes our understanding of the evolutionary process. We just have one more fossil close to Archaeopteryx which places the two together in their own group just outside the formal bird group, the Avialae. We still have a great transitional sequence from dromaeosaurs to birds. Menton makes the incomprehensible statement: “What he’s arguing is that … thanks to his new discovery, Archaeopteryx should be classified a dinosaur, not really a bird at all. … We’re supposed to forget everything we have known [about] Archaeopteryx.” Huh? Archaeopteryx was always on the borderline between dinosaurs and birds, and this discovery just pushed it a bit closer to dinosaurs. Count on creationists with their rigid “created kinds” pigeonholes of nature to not comprehend that there are fossils right on the border between bird and dinosaurs. The rest of their article comments on how similar birds are to dinosaurs, which is a complete concession to evolution, but somehow Menton and Ham completely missed the implications of their own essay.
The ID creationist website, Uncommon Descent, can always be counted on to spin and misinterpret anything that doesn’t fit their rigid world view. Their first red herring claims that unless we have a perfect understanding of 100% of the fossil record, we can say nothing. In their words: “Cretaceous fossil record shows many features that we do not properly understand, and the most appropriate response is to withhold judgment and await further discoveries and analysis. This applies to the whole of the Birds Are Dinosaurs (BAD) thesis”. Utter garbage! Science is always tentative, never 100% final or certain, and we are constantly revising our hypotheses as new and better information comes along (unlike the static and determined world of the creationists, which does not permit doubt or change). Then the ID creationists repeat the falsehood that another “icon of evolution” has been debunked. Nope, we just learned some more about Archaeopteryx and have slightly modified its taxonomic allocation, but it’s still a perfectly good transitional fossil—along with hundreds of other recently discovered Chinese bird fossils the creationists never mention. Finally, they fall back on that old saw that Archaeopteryx is no longer a perfect rung on the “ladder of life”, therefore it is no longer a transitional fossil. As has been explained many times before, evolution is a bush, not a ladder—and many species co-exist and overlap in time.
Finally, Vox Day, the craziest of them all, launched into a long diatribe that barely mentions the fossil (other than that scientists have changed their opinion about Archaeopteryx, and somehow it doesn’t support evolution), and rants about the origin of life, Keynesian economics, falsifiabililty, and a whole range of topics that are completely irrelevant. P.Z. Myers answers him in elegant detail, so I won’t rehash the whole garbled post or P.Z.’s answers here.
The whole spate of creationist mendacity continues to raise the issue of how they can read an ordinary article about a scientific discovery and get everything wrong, as I documented again and again in my 2007 evolution book. Certainly, the fact that none of them has any relevant training in paleontology or anatomy, and can’t tell one bone from another, is significant. But most laypeople cannot dissect out the anatomical details of a technical article like this one, and they don’t go off the deep end like the creationists do. Instead, we seem to be looking at a huge denial filter to resolve their problem of cognitive dissonance. To them, evolution is evil, therefore any evidence in support of evolution must somehow be wrong, therefore any crazy rationalization about the fossil, or ad hoc system like “created kinds” must be erected to salvage their belief system inherited from a group of superstitious Bronze Age shepherds. To the rest of the educated world, it sounds batshit looney, but to the 40% of Americans who claim to agree with creationism in most polls, this kinds of garbage is swallowed hook, line and sinker—and no one seems to reach these people and set the record straight.
Even sadder is the implications of this kind of creationist spin doctoring for our public understanding of science. Scientists are supposed to make new discoveries which change or rearrange what we thought before, and give us new perspectives on nature. Then we get another fossil which does exactly that—and the creationists jump on it as evidence that all we said about Archaeopteryx in the past was a deliberate lie, and that it is no longer supports evolution. If we cannot get rid of creationist lies and distortions in our public discourse, it would be nice to at least make the public aware of the true nature of science, so they don’t interpret new discoveries as signs of weakness, but the strength of science, which is tentative, self-correcting and always learning new things.
- Xu X, You H, Du K Han F (2011) An Archaeopteryx-like theropod from China and the origin of Avialae. Nature 475, 465–470.