January 13, 2012
Dinosaurs of a Feather
A specimen of the non-avian dinosaur Sinosauropteryx, showing the ruff of simple protofeathers along the back and tail. Image from Wikipedia.
Poet Emily Dickinson once wrote, “Hope is the thing with feathers.” To fossil bird expert Alan Feduccia, however, anything with feathers is a bird and emphatically not a feathered dinosaur.
For decades Feduccia has been one of the most prominent members of a small and steadfast group of researchers who reject the growing body of evidence that birds are the descendants of one lineage of feather-covered coelurosaurian dinosaurs (the large and varied group which included tyrannosaurs, oviraptorosaurs, deinonychosaurs, therizinosaurs and others). Feduccia and like-minded peers have been provided no solid alternate hypotheses about where, when, why and how birds originated—they point to some yet-unknown lineage of creatures that might have lived more than 200 million years ago—but they insist that birds cannot be dinosaurs. Yet Feduccia’s argument in his new book Riddle of the Feathered Dragons is not quite that simple. Near the book’s conclusion, Feduccia writes “if [a creature] has avian feathers, it is a bird”—a view popular among dinobird denialists that some dinosaurs were, in fact, “hidden birds.”
Non-avian, feathered dinosaurs have been known to paleontologists since 1996. In the 16 years since the first such creature was found—a small theropod dinosaur preserved with fuzzy protofeathers and named Sinosauropteryx—scores of plumage-bearing dinosaur specimens have been discovered. These creatures exhibit a variety of different feather types, which has helped paleontologists, ornithologists and developmental biologists understand how feathers went from simple, wispy structures to complex, asymmetrical feathers that allow birds to fly.
Feduccia disagrees. He says that the protofeathers on Sinosauropteryx and other dinosaurs are, instead, collagen fibers from inside the animal’s body. This would keep dinosaurs comfortably scaly for those who don’t like the idea that birds are derived dinosaurs. But a number of coelurosaurian dinosaurs, such as Anchironis, Microraptor and others, have been preserved with more complex feathers that more closely approximate those seen on living birds. These structures cannot be simply cast off as collagen fibers or other quirks of preservation, and so Feduccia makes a strange argument. Microraptor and kin are not dinosaurs, Feduccia argues, but are instead birds that lost the ability to fly and were molded into the form of dinosaurs through a circuitous evolutionary pathway. By employing a very narrow definition of what a feather is, and by asserting that only birds can have feathers, Feduccia tries to rearrange evolutionary relationships through semantics.
When Sinosauropteryx was discovered, the dinosaur seemed to be an enigma. Paleontologists were not optimistic about the prospect of finding dinosaurs with feathers. Such intricate structures would only be recovered in instances of exceptional preservation. But additional discoveries since 1996 have confirmed that the find was not a fluke. And the fuzzy structures preserved along the backs of these dinosaurs contain an important clue that they are, in fact, protofeathers. In 2010 a pair of papers was published regarding the reconstructed feather colors of dinosaurs. These findings were based on melanosomes—microscopic organelles found in feathers that, depending on their shape and distribution, create different colors and sheens. Such structures would be expected in feathers, but not collagen, and so when paleontologists were able to identify melanosomes in the fuzz of Sinosauropteryx, they provided new evidence that the dinosaur carried protofeathers.
Perhaps more importantly, however, there is no indication that creatures such as Oviraptor and Velociraptor were birds. Analysis after analysis has found them to be unequivocal, non-avian dinosaurs within the coelurosaur subgroup. Although Feduccia hypothesizes that birds originated from some mysterious Triassic ancestor, and then bird-like dinosaurs evolved from early birds, there is not a shred of evidence that such an evolutionary repeat ever took place. The idea is an attempt to remove uncomfortable facts in the way of a preconceived view.
Many of the book’s arguments take on a “because I said so” tone. Feduccia states that dinosaurs could not have been covered in protofeathers at any point because their archaic plumage would have gotten wet and mucky in the rain. Likewise, Feduccia argues that dinosaurs could not have evolved the long arms necessary for flight, and he casts dinosaurs as relatively sluggish ectotherms that had more in common with lizards and crocodiles than birds. None of these points are discussed in detail or backed up with sufficient evidence. Readers are left to take Feduccia at his word.
Ultimately, though, many of Feduccia’s objections boil down to a rejection of a methodology known as cladistics. This method of determining relationships among organisms is based on the analysis of shared derived characteristics—specialized features found in two organisms or lineages and their most recent common ancestor. Researchers look for numerous traits, record whether the traits in question are present or absent, and then insert that mass of data into a computer program that produces a hypothesis about the relationships among the various organisms included in the study. The point is not to find direct ancestors and descendants, but to figure out who is most closely related to whom. The method is not perfect—which organisms are included, the choice of traits for comparison and the way those traits are scored all affect the outcome. Still, this process has the benefit of requiring researchers to show their work. Each evolutionary tree resulting from such methods is a hypothesis that will be tested according to new evidence and analyses. If someone disagrees with a particular result, they can sift through the collected data to see if an inappropriate trait was included, an essential organism was left out, or if there was some other problem. Cladistics is useful not because it results in a perfect reflection of nature each time, but because it allows researchers to effectively examine, test and improve ideas about relationships.
Cladistic analyses have repeatedly found that birds are nested within a subgroup of coelurosaurian dinosaurs called maniraptorans. The result has only become more robust as additional archaic birds and non-avian feathered dinosaurs have been found. Feduccia argues that such results are deeply flawed, but he does not provide a viable alternative for how we should identify the relationship of birds to other organisms (an essential task if we are to figure out how birds originated). Categorizing organisms on general appearances, or making feathers synonymous with birds alone, will only confuse our understanding of prehistoric life. And, contrary to his protests, Feduccia seems to welcome cladistic results that support his own views. In a section of the book on the weird oviraptorosaurs, Feduccia plays up the importance of a 2002 paper that used a cladistic analysis to support the conclusion that these creatures were archaic, secondarily-flightless birds, even though additional studies have not supported this interpretation.
Riddle of the Feathered Dragons is an intensely frustrating read. The tome is a 290-page position piece that ultimately leaves the reader stranded. Feduccia is so concerned with turning feathered dinosaurs into birds that he ultimately neglects to present any reasonable hypothesis for where birds came from. The poor production of the volume only makes things worse (the illustrations are so tightly packed in places that they make it difficult to find where the captions end and the regular flow of the chapter picks up again.)
Although I wholly disagree with Feduccia, I had hoped that Riddle of the Feathered Dragons would explicate what opponents of the dinosaurian origin of birds believe about where avians came from. Simply repeating “birds are not dinosaurs” is not enough—positive evidence must play a role in forming an alternative hypothesis. The riddle of the “feathered dragons” is not where birds came from. The puzzle is why some scientists continue to insist that birds cannot be dinosaurs.
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Good heavens, has this author ever been chased by a gaggle of angry Canada geese? Just try and pretend those damn things are not descendants of ferocious pack-hunting dinosaurs!*
*(The preceding comment is intended to be non-serious, and does not represent a legitimate scientific argument.)
Lovely article Brian! Feduccia’s arguments are laughable more often than not – who keeps giving this man funding to do research?!
Just one point: ‘characters’ and “traits” are fundamentally different – it’s a pet peeve of mine when people misuse the word. Traits have no scientific definition or value, characters do. (see one of my blog articles of you wish)
I’ve said it before, and I’ll say it again: BANDits (Birds Are Not Dinosaurs-supporters) are no better in their arguments than creationists and climate change deniers. http://tinyurl.com/832y3g3
Your (repeat) dissection F. is excellent as usual! Many thanks.
Regarding the supposed “proto-feahters” I urge everyone to have a close look at Christian Foth’s paper
http://www.springerlink.com/content/u71014417j3214j0/
Christian took an extant bird (a dead one, obviously), and flattened it in an old printer’s press. Surprise, surprise: the non-proto-feathers of the extant birds looked very much like proto-feathers after this process. And the bird had a “crest” after flattening that isn’t there in life.
Really? “Because I say so” is good enough for a book — a scientific book? It just seems like some people aren’t comfortable with the whole feathered dinosaurs thing.
Thanks for this. I’ve been wondering what the “birds are not dinosaurs” contingent was thinking about the finds from Liaoning and such.
I’ve been waiting for the reviews of this to start rolling in, and the results have not been disappointing. Well done.
“Feduccia argues that dinosaurs could not have evolved the long arms necessary for flight, and he casts dinosaurs as relatively sluggish ectotherms that had more in common with lizards and crocodiles than birds.”
The sad thing is, if this book were written in the 1950′s, we’d all be reading it and laughing at hilarious old theories about dinosaurs utterly failing at life.
The other, possibly sadder, sad thing is that if this dude was trying to argue that dolphins aren’t mammals, everybody would see him as a lunatic.
And I love how he apparently avoids the most obvious question:
Feduccia: “BIRDS ARE NOT DINOSAURS!’
Sane Person: “Well then, what are they?”
Feduccia: “THEY ARE NOT DINOSAURS!”
Sane Person: “But… what ARE they?”
Feduccia: “NOT DINOSAURS!”
Sane Person: “I think your argument might be invalid.”
I think the real issue with this book is that Feduccia recycles an awful amount of material from his 1999 textbook The Origin and Evolution of Birds, right down to the text. That in itself is frustrating because any updates in paleo-ornithology are mixed with outdated theories and assumptions (not all of them necessarily Feduccia’s). Additionally, many of the chapters seem to detract or lose sight of the book’s supposed thesis.
Feduccia is by no means completely stupid – his ideas on the origin of flight and the evolution of modern birds are spot on – but sometimes he can get too personal when arguing that birds aren’t dinosaurs.
I remember researching his papers for a course assignment. I ended up putting them all in a folder named “Alan Rant”, as they were long on verbiage and short on facts.
Back to the 90 Alan Feduccia argued that Dromaeosaurids were dinosaurs unrelated to birds now he claims that dromaeosaurids are birds unrelated to dinosaurs!
And with these silly contradictions he still argues that the bird-are-dinosaurs theory is just a dogmatic conspiracy. Should we laugh or feel sorry for him?
Good gracious, that must mean that some dinosaurs must have made it onto the Ark some 10000 years ago and then must have metamorphosed into current day birds! What will the religious right do with this new information?
Seriously though modern thinkers, I believe, know that the above mentioned bird like dinosaurs were not birds, they evolved into birds……
I once met a college professor (apparently) on a forum who proposed the same arguments… yes, he even played the conspiracy card… From his badly-formatted ramblings, I wouldn’t have guessed he was more than just some troll. But he at least had an answer to the “What are birds?” question: mammal relatives!
I’m more interested in the idea that the Feathered Serpent of Mayan and other pre-Columbian mythologies might have had a real life prototype!
PS My first reaction on seeing the pix of Sinosauropteryx was “How sweet!” I wonder why?!
@Vrahno : so, rather then birds evolving from bare skinned, egg laying bi-peds with utterly useless arms he rather has them evolving from woolly quad-peds whom give birth to living offspring..
The sense just ran for the hills, screaming and waving arms. Someone should go and comfort it.
Ok so we don’t know where Birds came from we can guess and research and keep looking and make all our arguments but we still don’t know.
I think that’s a very familiar argument we don’t know where modern man came from either.
Maybe both Birds and Man came from the same creator.
The problem is that these people do not know where to find the answers… If they will read the book of Genesis in the Bible they can know what is true and what is BS !!! Mostly they have been educated out of what little brain they were born with !!! We know that the creatures on the land and the creatures of the sea and the creatures in the air were all created !!! We know also who created them… Many of the creatures that were created have become extinct and it matters not one whit when or how they came to be… That question is left to those who have nothing better to do than idle mind meanderings !!!
Gerald Flaherty and Richard R Hutchinson, are you guys for real?
Terrific article, and very entertaining.
Richard R Hutchinson: I have to disagree with your notion that nothing is important except what’s written in the Bible. The Bible was written not by God but by men, complete with all the same human failings of men (and women) today. Trying to force people to choose between science & religion is silly & fruitless; most enlightened people will choose science.
Heinrich Mallison: Thank you for the url for Foth’s paper. Fascinating stuff!
Swan Thompson
Dallas, TX
Oh my. How some rather smart people can be so extremely stubborn and stupid is beyond me. That guy is fighting an uphill battle with the sun in his eyes. He ain’t gonna win, not when (very very nearly) the rest of the world has so much evidence against his confused and blind theories.
It must be pointed out that A.) Feduccia is not some wing-nut spouting contrarian nonsense for no purpose, he’s a highly respected ornithologist posing well thought-out and challenging questions, and 2) a point the reviewer misses is his valid argument that a major weakness of the bird-dinosaur arherents is, as Feduccia correctly points out, the “verificationist” approach taken by many of the researchers in attempts to support the dominant paradigm. This is antithetical to the principles of the scientific method–one does not set out to “prove” a hypothesis. A philosophy of “falsification” using all valid available tools to CHALLENGE it is the driving force behind good science. Consensus on an issue, such as the bird-dinosaur nexus, dampens critical thinking. A scientific gadfly like Feduccia is of immeasurable value, and he should be applauded, not criticized. This book is a fantastic addition to the literature on this topic and I expect it will force anyone who reads it to at least take a long second look at conventional wisdom.
You guys have stated categorically that Microraptor, for instance, was not a bird. This is not a matter of semantics. All birds fly with feathered wings or are descended from animals that did. Microraptor flew with feathered wings. What, specifically, in the “1″s, “0″s and “?”s of your various data matrices is more dispositive in this issue than flight with feathered wings?
Ahh haters’ gonna hate.
Nick (#21) has a great point. People like Feduccia are healthy for science, presenting the alternate view and challenging the current dogma, whether you agree with him or not.
Honestly I think everyone is so sore on the idea he presents because it challenges the cool dinosaur-into-bird relationship we have all grown up with, not that his argument is “invalid”. Deviating from the conventional should be encouraged, it gets me to think and he brings up some excellent ideas. I got a chance to meet and talk to him, just because his book has a “because I said so” attitude, the man in person presents a very different aura and he has very plausible explanations.
He brings up some very valid arguments. Think about this: archeopteryx predates velociraptor and most other theropods. Pretty much everyone can agree that modern flightless birds of today had ancestors who could fly. Why not conclude, or at least agree that it could be possible that:
ancestral flying birds are to ostriches, so archeopteryx is to theropods? It makes sense to me…
No, no, and no, respectively.
Feduccia’s ideas on the phylogeny and evolution of modern birds diverge wildly from those of most of his colleagues.
His questions are not well thought-out at all, they all rely on his lack of knowledge about dinosaurs other than birds – not being interested in them, Feduccia hasn’t even tried to keep up with the literature on them, so everything he says is 30 or 40 years in the past. As late as his 1996 book (and probably the 1999 version, too), he claimed matter-of-factly that hadrosaurs were aquatic! He clearly had no idea this hypothesis had been abandoned at least twenty years earlier! It’s all so cringeworthy.
Challenging? His 1980 book may have been challenging. The later repetitions of his arguments, and the goalpost-shifting*, have been nothing but boring.
* from “maniraptorans are lizardlike dinosaurs that have nothing at all to do with birds whatsoever” to “maniraptorans are secondarily flightless birds that have nothing at all to do with dinosaurs whatsoever”, most notably.
Verificationist? Are you kidding us? Which paper uses a verificationist approach???
Absolutely. I just can’t see where anyone who works in that field has been verificationist.
Again, he outlived his usefulness as a gadfly decades ago. He should finally accept that several of his hypotheses, and their goalpost-shifted inversions, have been falsified, and move on to doing something useful to science.
What’s up with him? Is he afraid to admit he was wrong? A scientist can’t afford this fear.
Not if they have any idea of the data behind the conventional wisdom, I’m afraid.
Besides, don’t start a Galileo gambit. Feduccia’s idea on the origin of birds and their flight was conventional wisdom for most of the 20th century. It was not abandoned on a whim.
It is. Definitions of names aren’t carved in stone somewhere.
Assuming it flew (which is still not clear, though IMHO likely), and assuming that it didn’t evolve flight separately from today’s birds, it is a bird under your definition – and so are Velociraptor and Utahraptor, and perhaps Oviraptor, possibly even Therizinosaurus. If that’s how you want to define “bird”, be my guest, but don’t be surprised if you can’t find many followers.
The definition is just a matter of where, on which internode, we tie a label to the tree of life.
“We all”? How old are you? Seriously?
*sigh*
First, don’t misquote him. He says that Archaeopteryx predates the other maniraptorans (dromaeosaurids such as Velociraptor, as well as troodontids, oviraptorosaurs, that kind of thing – not, say, tyrannosauroids, carnosaurs or ceratosaurs).
Second, Feduccia is committing a misunderstanding here that he has never bothered to correct: nobody claims that Velociraptor or any other dromaeosaurid is a direct ancestor of Archaeopteryx! It’s plainly intellectually dishonest of him to continue claiming so. People have corrected him on this in print for decades now, probably ever since his 1980 book came out, and he simply doesn’t care – he keeps repeating his claim, without bothering to show he has so much as read the critiques.
Third, Archaeopteryx does not predate all dromaeosaurids or all troodontids. This has been known, if you accept isolated teeth and the like as evidence, since the 1980s; more recently, the Jurassic of northeastern China and Wyoming has yielded well-preserved fossils that flatly disprove Feduccia’s claim. Feduccia has never, to my knowledge, addressed most of these.
Of course it’s possible. It’s just not the simplest explanation for the data we have today.
And don’t overestimate the importance of Archaeopteryx. Feduccia loves to.
I’ve exchanged a few e-mails with him. I confirm that he’s quite nice. (He sent me a paper reprint of one of his papers, too.) That just has no bearing on whether any particular idea of his is defensible.
His ideas all seem plausible if, like him, you don’t know what he’s talking about.
David–I couldn’t disagree more. You are certainly entitled to your opinions on the validity of the “birds are dinosaurs” hypothesis, but I disagree with you that Feduccia could be considered ignorant of dinosaurian morphology–your quote “lack of knowledge about dinosaurs other than birds – not being interested in them, Feduccia hasn’t even tried to keep up with the literature on them.” That is not remotely accurate, and demonstrates your lack of familiarity with Feduccia.
In this case, I highly recommend that you actually read the book if you haven’t yet. “Riddle of the feathered Dragons” is not merely some rehash of old arguments, it is a VERY carefully crafted reassessment of the situation that incorporates the fantastic wealth of recent fossils, both dinosaurian and avian from China and elsewhere.
My take on the whole thing is that these fossils, as Feduccia elegantly argues, fill in critical gaps from Middle Jurassic and Early Cretaceous that are crucial to resolving the issues–and are key to understanding these critical phases in avian evolution.
The perspectives gained over time, with more new fossils, will be what decides the issue, not strident claims that “the debates is over” (I quote Henry Gee directly here). Such a statement, and other similar sentiments, are indeed unscientific. When debate ceases, critical thinking screeches to a halt.
That’s fine, Nick, if you in turn agree to read more dinosaur literature. And why don’t you address Feduccia’s goalpost-shifting? He himself has never addressed it.
I’ve read Feduccia’s 1980 and 1996 books (the latter several times because it’s so well written) and several of his more recent papers and have, as I mentioned, corresponded directly with him.
“The definition is just a matter of where, on which internode, we tie a label to the tree of life.”
This is the nugget of the problem with the reign of cladistics in bird-origins research. The word “mammal”, as an example, has meaning without reference to a cladogram. In physiological terms the presence of mammary glands identifies a mammal. In terms of skeletal anatomy, a particular sort of jaw articulation does the trick. In Feduccia’s construct, “bird” means an archosaur that flies with a feathered wing (with the obligatory; and all descendants and common ancestor). In the cladisitics-only construct, the word “bird” only has meaning in reference to a particular node in a particular cladogram.
Maybe this is an issue of semantics, after all. You have rendered the word ”bird” meaningless. I suggest you stop using it.
I’m currently reading ‘Riddle Of…’, and although I think I appreciate the gist of the author’s argument and viewpoint, I also find parts of it frustrating. Assertions are made, such as the one about theropods being inherently unlikely to evolve the long arms necessary to become wings, because the ancestral dinosaur ‘bauplan’ was a long-legged, short-armed biped. Evidently no-one told the brachiosaurids about this.
Another thing that niggles me (which I suspect would be explained as convergent evolution) is why birds are bipeds. If, as Feduccia seems to suggest, they evolved from an arboreal quadruped, via a gliding stage, why did they become bipedal, when pterosaurs and bats were (are) not?
Why does he devote an entire chapter to Thomas Huxley, whose arguments regarding possible avian descent from dinosaurs are only really of historical interest now? The point is not *who* argues, but whether they can support their hypothesis with evidence.
As some others have commented, the content of the book is not always as clearly presented as it might have been, which is a pity. Apart from the illustrations and captions being cluttered, several were scanned at too low a resolution, which looks oddly amateurish in what is presumably intended to be an academic publication.
I totally agree with you about the origin of birds. I think it is, quite frankly, ridiculous that a few actual scientists still do not accept the fact that birds are living dinosaurs.
However, I also disagree with you that dromaeosaurids and troodontids are not birds. I believe that all Paravians are birds. In other words, I feel like we should draw the line between ‘non-avian dinosaur’ and ‘bird’ at the split between the Oviraptorosaurians, and the Paravians.
In other words, I believe that dromaeosaurids, troodontids, and Avialans all form a polytomy, with each other, and that the common ancestor of all 3 of them was the first bird.
Pterosaurs are the ancestors.
Google it.