Talk:Origin of birds/Archive 1

Archive 1

Archive 2

Vaned

The term "vaned" is used in the intro text. Is the author looking for "veined" possibly? — Preceding unsigned comment added by 211.30.15.177 (talk) 19:01, 7 February 2013 (UTC)

No, "vaned" refers to the fact that the barbs form a coherent flat surface, not the fact that it has a central vein-like shaft. See also "weather vane". MMartyniuk (talk) 19:58, 7 February 2013 (UTC)

The section on digit homology states that maniraptors are descended from dromaeosaurs, but this is misleading; the group cannot be descended from dromaeosaurs because dromaeosaurs are maniraptors. I'd edit the section to make it a little clearer, but I'm not sure what exactly it was intended to mean. 75.210.47.86 (talk) 05:50, 12 April 2008 (UTC)

Yes, there were some clear mistakes in that section. I hope to have removed them all. Thank you for being so alert!--MWAK (talk) 06:56, 12 April 2008 (UTC)

Are some dinosaurs secondarily flightless?

Cladistics neither supports nor denies the neoflightless hypothesis -- which is not a phylogenenic hypothesis per se. John.Conway 12:19, 15 September 2006 (UTC)

I edited the text accordingly, refering only to the phylogenetic position of Archaeopteryx w.r.t birds and deinonychosaurs. --Ollivier 12:51, 17 September 2006 (UTC)

Move?

Thanks for this long overdue page. Before formally submitting a proposal, I'd like to discuss here whether this page should be moved to "Origin and evolution of birds" or somesuch. Such an article does not exist, though it would be more inclusive, and the present title is kinda redundant with Feathered dinosaurs. Presently, there is no real place to discuss the Cretaceous radiation of birds really, i.e. how Confuciusornis, Gansus, the Hesperornithes, the Enantiornithes and "stuff" like Gargantuavis go together (and then throw in "secondary flightless theropod-like birds"), but that issue is crucial for getting an adeqate picture of avian evolution. Dysmorodrepanis 10:14, 30 September 2006 (UTC)

Maybe a single page treating both the origin of birds and their evolution in the Mesozoic would become too long. Much can be said about both topics... So, sure I would support the creation of a page devoted to the Cretaceous bird radiation, but I think it would be best to make it separate from the debates regarding Archaeopteryx and its dinosaurian relatives, in order to keep both pages short enough to be easy to read. --Ollivier 21:02, 30 September 2006 (UTC)

Archaeopteryx and deinonychosaurs

Mayr et. al. (2005) showed that the Archaeopteryx specimen they described possesses the hyper-extendible second toe previously found in deinonychosaurs. This character brings Archaeopteryx and deinonychosaurs together and suggests that deinonychosaurs were birds that evolved from Archaeopteryx. Also, therizinosaurs, alvarezsaurids, ornithomimosaurs, and oviraptorosaurs may also be birds, since they lived after Archaeopteryx. Thus, update the section titled "Are some dinosaurs secondarily flightless?".

Mayr, G.; Pohl, B. & Peters, D. S. (2005). A well-preserved Archaeopteryx specimen with theropod features. Science 310(5753): 1483-1486.

The second toe proves not really much. Deinonychosaurs and birds (Paraves) were the closest relatives anyway and by the late Jurassic had just barely diverged enough to be considered separate (also, consider the lack of a robust pre-Late Jurassic fossil record for either). Like feathers, the hyperextendible second toe (AKA "raptor claw" but not necessarily with the claw) seems to be a feature that pops up every now and then all over the lineage. For the time being, I put the other "birdish" theropods in the section, but suffice to say that if there is one lesson from the last 10 years' research, it is that neither flight nor feathers are useful to determine how "avian" some theropod was. Snout and caudal vertebrae are much more useful, and these characteristics suggest that the bird-like theropods may be better seen as secondarily flightless non-avian theropods. The "secondarily flightless birds" hypothesis is basically a relic of those pre-Microraptor days. There is now hardly a gap large enough in the fossil record for some early avian to "branch back" into the "mainstream" theropod lineage, which looks not a t all like an evolutionary "tree" anymore but rather like some thorny tangle of shrubbery.

Speaking of shrubbery, of course one should never say Ni. But the evidence for some dinos being secondarily flightless birds as is accepted at present is a far cry from what it was around 1999. Dysmorodrepanis 16:48, 3 October 2006 (UTC)

Nomingia is a case in point: it has a pygostyle, but that is very "primitive" - most likely too primitive for a Late Cretaceous derivate of Early Cretaceous birds as presently known. The "Jeholornithiformes" and Omnivoropteryx suggest that it cannot be completely ruled out, but the evidence is against it as it would require de-fusion of the caudal vertebrae - theoretically possible, but utterly improbable as far as anyone can say. For the time being, it seems safe to assume that every step towards a pygostyle and a beak the different early avian lineages made was all but irreversible and that secondarily flightless birds should reflect this. Hesperornis does for certain, even though it seems to have lost and re-evolved teeth! Dysmorodrepanis 16:56, 3 October 2006 (UTC)

Still, the paper is good and importatn; it now seems that hyperextensibility of pedal digit II was something which popped up here and there among theropods and thus it can be assumed that the MRCA of birds and non-avian theropods had it at least in an incipient state. Put paper into ref section and discussed implications thereof in article.

BTW I finally got me "Mesozoic Birds" and it confirms my suspicion: most "true" avian (as opposed to paravian) autapomorphies are found in the skull. Witmer's discussion of "Protoavis" is remarkable fair and lucid (he still thinks it's at least dubious and prolly a chimera, but he does not reject it out of hand as many do). Dysmorodrepanis 16:53, 15 October 2006 (UTC)

Gizzard

The gizzard does not provide evidence for the bird-dinosaur connection as it is a character shared with crocodiles.--MWAK 06:42, 15 October 2006 (UTC)

Thermopolis Archie & "Protoavis"

The discussion of the Mayr paper suggests that their intent was not really to propose such a hypothesis, but merely to point out some features in the Archie specimen that suggest it indeed belongs to a side branch. I disagree with "Protoavis" not having to do anything with it - in the radical form (i.e. the one that commentators implied Mayr et al supported, which they denied - shall add discussion letters to refs shortly) it would have indeed major bearing as that ultimately boils down to the ancestor of maniraptorans and possibly most theropods even was flying and a "Protoavis"-like critter would fit the bill. That of course implies P. is valid, and my take on that is it isn't. But even then, the most radical possible interpretation would more or less require that something much like P., but a valid form, should lurk in the fossil record, undiscovered as of yet. The fact that "Protoavis" taints everything it touches, so to speak, is probably one of the two main reasons it is left out of Mayr et al's discussion (the other is that they're too careful to explicitly suggest that flight was lost and not gained independently). A major drawback of their phylogenetic analysis is the non-inclusion of most of the "interesting" early birds. The placement of Archie and Confuciusornis on different branches hinges mainly on the diapsid skull. To really raise eyebrows (or possibly not to), Yanornis, Shenzhouraptor, Omnivoropteryx and Liaoningornis, for example, should have been included. In its present state, it is neat, but not earth-shaking. "Archaeoraptor" was earth-shaking - the two components on their own proved ultimately to be far more important on their own than as a composite fake, showing that a) advanced birds existed in the Early Cretaceous, and probably more than one lineage too, and b) that there were 4-winged flying dinos not very closely related to birds - but close enough that their flying ability was somehow connected.
And as I hinted at in the article, a multiple-origin scenario of paravian/theropod flight seems way more parsimonious than the assumption that the Paraves or even most theropods arose from flying ancestors and lost flight multiple times independently (a critter like Protarchaeopteryx, mind you, was well suited to evolve both ways - towards and away from flight. I think these are the actual "transitional" stage: incipient flight capabilities but not flying yet. That would explain things like the pelvis of Rahonavis, which the flying-ancestor model cannot: it is not avian, not even like that of Archie, but it seems to have done fulfilled the same function about as well as in Archie - there are pictures in Geist & Feduccia which speak better than words). The functional diversity of paravian modes of flight around 110-100 mya is hard to reconcile with the latter: even though both Archie and Confuciusornis were incapable of a supporting upstroke, their mode of flight seems to have been radically different as evidenced by their remiges' shape. Add to that Yanornis, Gansus, and the early enantiornithine birds which essentially were "modern" flyers and lived not too far distant in space and time from Confuciusornis - too close in fact to be derived from it - and there you go. Dysmorodrepanis 09:53, 24 October 2006 (UTC)

I noted on the Dutch corresponding page (from which quite some stuff could be translated) that what I was referring to as the "most radical" hypothesis is called the "birds came first" model. See the Dutch page on why a "Protoavis"-like critter is of key importance for that. Again, BFC is not what Mayr et al want to imply - their data is open to both ways of interpretation (widespread loss vs widespread evolution of flight) and the former opens up cans and cans of worms, whereas the latter resolves many questions to satisfaction if you get yourself to let go of flight-in-general as an avian characteristic. Which should not be a problem because it has been done for feathers. "True" avian flight (2-winged, flapping, with pronounced recovery/upstroke and a sternal keel as THE flight muscle attachment) seems to be how flight must be outlined according to current knowledge if one wants to limit it to Aves sensu stricto. And all this coming together is by and large making the evolution of birds, contentious as it may be, more and more an in-your-face to creationists and IDlers - they evolved, that much seems to be sure, by a roughly 50-million-years-long process of trial and error and trying out and rejecting multiple approaches to the challenge, not out of thin air (i.e. by special creation) or according to a pre-laid plan (i.e. by ID), and ultimately only a fairly marginal side branch survived the Big One. It is still not a good model to resolve macroevolution vs microevolution; though it might initialy suggest so, it's really what could be called "mesoevolution", i.e. major changes to a bauplan, but not actually evolution of an entirely novel one (e.g. endo- or exoskeletons from soft-bodied precedessors) . For that, my best guess is that we're indeed dealing with two fundamentally different ways of evolution, with "true" macroevolution being essentially genome/chromosome major-scale rearrangement- and microevolution being essentially point-mutation-driven; Hox genes vs the "proto-feather" mutations in chicken embryos seem to support this. Dysmorodrepanis 10:14, 24 October 2006 (UTC)

Well, you address many things and I'm not quite sure on what points exactly (if any) we are in disagreement :o). Perhaps I can make clear what I think are the basic issues:

1. The Mayr paper doesn't merely suggest, it indicates. Cladistics is an exact science (well... :o) and the exact outcome of the very formal procedure is given. Of course we all know that the next analysis might render an opposite result and given this fundamental incertainty the paper might in the higher sense be a suggestion to at l(e)ast give the hypothesis the attention it deserves. But at itself it is a prima facie indication the hypothesis is true.
2. Of course Archaeopteryx's "belonging to a side branch" simply is the Paulian hypothesis.
3. Indeed a radical BCF-model is emphatically not what Mayr e.a. intended to propose. And their paper itself cannot really be read this way — their data do not support this at all. All the confusion stems from an editorial mistake in the abstract, which spoke of "challenges the monophyly of Aves". This of course doesn't make any cladistic sense — Aves is by definition monophyletic — and inadvertently suggested support for the MANIAC-position.

Anyway, I'm glad you like the Dutch version ;o). It certainly has one quality the English article still lacks: describing the BAND-position, which distasteful as it might be, is still mandatory under Wikipedia NPOV policy :o).--MWAK 11:54, 24 October 2006 (UTC)

I'd still say "suggest" as far Aves in general are concerned - it does "indicate" the findings for the two "early birds" analyzed only, whose placement in the same (i.e. Aves sensu stricto) lineage as of recently became more and more dubious (or, its saurian skull grew more and more in significance seeing that it was fairly different in other Early Cretaceous birds). So the one real suggestion here seems to be to remove Confuciusornithidae from Aves sensu stricto, which is fine with me, or to expand "birds" to include Caudipteryx and Deinonychus, which is not barring further analysis of the taxa I mentioned. I expect that several early birds will turn out to be examples of parallel evolution, and Confuciusornis is a prime suspect here. Dysmorodrepanis 18:05, 24 October 2006 (UTC)

Yes, but we should not forget that the Paulian hypothesis is about two certain factual states: whether certain Maniraptorian groups are more closely related to Archaeopteryx than to other species closer (than Archaeopteryx is) to extant Aves; and whether these groups are secondarily flightless. How Aves should be defined is an entirely different question — one that some would argue is not even scientific. The position of Confuciusornis in relation to species more closely related to extant Aves is for the factual hypothesis not very relevant — unless of course you argue that Confuciusornis is more distantly related than Archaeopteryx! Again a different question is whether Confuciusornis "suffers" from a certain degree of homoplasy and whether including some extant species would have rendered a more traditional result. This will probably soon be done and we'll see what will be the outcome :o).--MWAK 07:54, 25 October 2006 (UTC)

"dinosaur" does not refer to birds

<<modern birds are dinosaurs and dinosaurs are, therefore, not extinct>>

Not at all. A misuse of language. "dinosaur" never refers to birds. Calling dinosaurs birds is like calling the Japanese Caucasians. Voortle 14:34, 24 November 2006 (UTC)

This is a peoblem stemming from the double use of the word "dinosaur" as both a common name and a scientific name (which is incorrect--it is only a sicentific name). The group Aves belongs within the group Dinosauria according to phylogenetic taxonomy, so Avians are members of dinosauria. Whether or not "birds" are dinosaurs is a matter of how you define the word "bird". If you define "bird" as a member of the clade Aves, then birds must be dinosaurs. If you define bird as "a bipedal animal with feathered wings" and are using a paraphyletic approach, then birds may not be dinosaurs (but many "dinosaurs" would now be birds, like Velociraptor, Oviraptor, etc.)Dinoguy2 15:46, 24 November 2006 (UTC)

Microraptor, not Velociraptor. Evidence for feathers (except maybe "proto-down" in juvies) in top-level predatory theropods is still missing IIRC. Makes not much sense ecologically either - with feathers come novel parasites, and this drawback would be outweighed by flight, thermoregulation or social function; the former two did not apply to large "raptors" and the last could (and likely was) achieved differently, eg by skin flaps like in other "reptiles". "Dinosaur" and "bird" as vernacular terms are form taxa - groups that are diagnosable phenetically, but not phylogenetically.

A recent paper suggests that even the Dinosauria (including Aves) may be poly- or even paraphyletic, but the Dinosaur Mailing List was very skeptical and I would agree with the arguments put forward there. Dysmorodrepanis 21:47, 24 November 2006 (UTC)

"Evidence for feathers (except maybe "proto-down" in juvies) in top-level predatory theropods is still missing IIRC. Makes not much sense ecologically either - with feathers come novel parasites, and this drawback would be outweighed by flight, thermoregulation or social function" Care to tell this to moa, phorosrhachids, kiwi, etc.? No maniraptoran with integumentary impressions has ever been shown to lack feathers. There is not one instance of feathers disappearing along with flight, no matter how modified away from flight the form is, so there is no reason to suspect that even the largest maniraptorans would lack feathers.Dinoguy2 01:11, 25 November 2006 (UTC)

Presence in crown-group taxa of one lineage of a clade does not imply presence in crown-group taxa of another as long as presence in basal taxa - indeed, relationship of lineages inter se, remains unresolved. What can be indeed said is that once acquired, feathers are not easily lost, but are they autapomorphies or not? I'd rather still consider it unresolved. "There is not one instance of feathers disappearing along with flight", Olshevsky/Paul would be overjoyed at reading this ;-), but for the time being, I find it easier ATM to also consider "flight" without any further qualifications (such as "flapping two-winged flight with significant downstroke contribution") to be paraphyletic in theropods. We urgently need a redux of Mayr et al's Science paper with larger taxonomic sample; while ground-breaking, a bitter taste remains for non-inclusion of some key taxa (such as Liaoningornis), and if such a study were conducted, I personally expect the results to be a minor earthquake (or bolide impact if you will). More importantly, a larger avian/NAT sample will allow to evaluate the resultant cladogram, grouping unquestionably monophyletic lineages, which should resolve at least some of the incerta sedes better. Dysmorodrepanis 17:48, 26 November 2006 (UTC)

And once such a paper is published, it's findings can be reflected in the articles here. Howerver, it has not, and the overwhelming consensus in the literature is that "birds are dinosaurs" and that all maniraptora were probably feathered. Dissenting views or variations (Czerkas, Paul, Olshevsky, Martin et al.) should be discussed but not emphasized in favor of the majority view. This is an encyclopedia, and as such should reflect the current status quo. Anything more or less than this is original research.Dinoguy2 17:54, 26 November 2006 (UTC)

Simple phylogenetic bracketing shows that the hypothesis that all Maniraptora had feathers is the most parsimonious. Of course very large maniraptors might have been "naked", but Velociraptor was rather small and hardly a top predator. The main point is that Voortle's premise <<"dinosaur" never refers to birds>> is simply false. And this is not just because some small group of paleontologists uses a different vocabulary; when I showed my 27 months old nephew a picture of a life-size tyrannosaur model, he said just two words: "bird!" and "bite!". Very perceptive of him. ;o)--MWAK 08:46, 25 November 2006 (UTC)

<<The main point is that Voortle's premise <<"dinosaur" never refers to birds>> is simply false.>> No, it's not false. In pop culture and common usage, "dinosaur" means non-avian Dinosauria. One may argue that the Japanese should be considered Caucasians, because of the "humanness" of both groups, but that doesn't change the fact that the "Caucasian" by definition, does not refer to Japanese people. Similarly, just because some may argue that birds should be considered dinosaurs, does not change the fact that "dinosaur" by definition does not refer to birds. The dinosaurs became extinct 65 million years ago, leaving their decendants (the birds). Voortle 15:44, 25 November 2006 (UTC)

"In pop culture and common usage, "dinosaur" means non-avian Dinosauria" Luckily, the current Wikipedia article is not on pop culture or common vernacular terms in american English. It's about dinosaur science, and the vast, vast majority of dinosaur scientists agree with the phrase "birds are dinosaurs". There are countless sources for this listed throughout the relevant articles.

""dinosaur" by definition" What definition? The phylogenetic definition of Dinosauria is usually either Iguanodon + Megalosaurus or Triceratops + Birds. The apomorphy-based definition usually refers to the perforate acetabulum (a feature shared by dinosaurs and birds). Additionally, the Dinosaur article errs on the side of conservatism and uss a paraphyletic definition anyway! Despite the fact that virtually all modern paleontologists use a cladistic definition of dinosaur that includes birds, the article does not. It's not exactly out of line, therefore, to point this fact out in the present article.Dinoguy2 17:45, 25 November 2006 (UTC)

Also the comparison with the relation between "Caucasians" and "Japanese" is false (beside the dubious anthropology): in this example the Japanese are not the descendants of Caucasians. What Voortle proposes is something akin to saying "Germans aren't Caucasians but the descendants of Caucasians". --MWAK 08:33, 26 November 2006 (UTC)

Phylogenetic challenge to the coelurosaur hypothesis of bird origins

Kurochkin (2006) published a scientific paper revealing convergent evolution between theropods and birds. He concluded that Archaeopteryx and the enantiornithines descended from a theropod group in the Upper Jurassic, with modern birds and their relatives diverging from an archosaur ancestor in the Upper Triassic. This conclusion was based on the differences in the finger digit homology of birds and theropods. His paper confirms not only that birds aren't really descended from theropods, but also that Protoavis is avian. The cladogram below reveals a different tale about bird relationships:

Archosauromorpha
|--Theropoda
|  |--Coelurosauria
|  `--+--Troodontidae
|     `--+--Alvarezsauridae
|        `--+--Oviraptoridae
|           `--+--Dromaeosauridae
|              `--Sauriurae
|                 |--Vorona
|                 `--+--Archaeornithes
|                    `--Enantiornithes
`--+--Protoavidae
  `--+--Confuciusornithidae
     `--Ornithurae
        |--Zhyraornithidae
        `--+--Liaoningornis
           `--+--Ichthyornithes
              `--+--Hesperornithes
                 `--Neornithes

Why did Kurochkin include Protoavis in his cladistic analysis?

Kurochkin, E.N., 2006. Parallel Evolution of Theropod Dinosaurs and Birds. Entomological Review, Vol. 86, Suppl. 1, pp. S45-S58. —The preceding unsigned comment was added by 72.194.116.63 (talk) 01:52, 10 January 2007 (UTC).

"Revealing" parallel evolution goes a bit far (though it's obviously true prima facie as written here; toothless beaks are indeed an avian-NAT homoplasy... ;-) ). His paper confirms nothing; a cladistic analysis cannot "confirm" anything, only support a hypothesis (cladistics cannot even falsify a hypothesis, scientifically speaking, as it interprets evidence instead of being evidence). As long as his hypothetical protoavian archaeosaur has not been found, nothing is "confirmed"; this paper (in an entomological publication?!) shows the debate is not over but that's all. Whoever treats Protoavis as a biological entity (instead of a hollow shell of a taxon) deserves what he gets IMHO; there is no good case for it being non-chimeric. Of course every cladistic analysis that utilizes the (with almost 100% certainty) archaeosaurian bits assigned to Protoavis and believes it to be avian will yield "proof" that avians are descended from archaeosaurs... the Avicephala don't bear that name without a reason. These should have been included in the analysis. Also, where's the outgroup?

I'd say: forget the conclusions. Barsbold had figured out what was going on 20 years ago, as far as anyone can say now. Him being from Soviet Mongolia, I would not exclude that he meant his statement typologically which is wrong of course, Trofim Lysenko be cursed, but it seems he was very much on the right track: "bird" is a form taxon if not all but restricted to Pygostylia or at least Ornithothoraces, this much is what we can certainly say. It is fairly likely that either Archie or Confuciusornis represents a stem-group divergence from the lineage leading to Neornithes, but maybe neither did; it is near-certain that they didn't both. Try nipping the tree between "Protoavidae" and Confuciusornithodae and rooting in theropods instead; this might actually be close to the real deal. It would at least be a phylogeny that is as good as they get these days.

But the paper does have a definite merit: that Archie is placed closer to the Enantiornithes, and Confuciusornis ("Confie"? ;-) ) closer to Neornithes. While I have reservations about Hesperornithes and would like to see the justification for placing them so high up, the Archie/Confie relationships make my mouth water. "Protoavis" should be thrown out and the dataset combined with May et al's recent paper, and I guess we might be on to something BIG... this is basically Mayr et al's analysis from the bird-end, with a nasty red herring. Dysmorodrepanis 04:50, 10 January 2007 (UTC)

To avoid a possible misunderstanding: Kurochkin didn't perform any cladistic analysis. The "cladogram" was based purely on qualitative judgments of Mr Kurochkin himself, a man who, however, really isn't qualified to judge. Kurochkin never implements correct cladistic methods.--MWAK 09:32, 10 January 2007 (UTC)

Oooh, and I hoped that he had accepted the inevitable at last ;-) What a pity! (I have nothing against cladistics [as a methodology, not as a science branch] - I just don't like it being considered something it isn't, such as "material evidence"; it is a means of reasoning, more akin to dialectics if you will. Case in point: the description of Archaeorhynchus does a cladistic analysis of said taxon which includes a most sweet set of other taxa. Here, Confie goes basal to Enantiornithes, forming a monophyletic clade with them... I think this is the first time I see it. And why not? I am not comfortable with it at all, but it cannot be dismissed; the cladogram again proves nothing BUT it shows that the idea needs further scrutiny before it can be dismissed)

Still, the standards of most cladograms in paleontology are pretty low compared to systematics of extant taxa - hardly you'll see bootstrap values etc, which are essential to interpreting a cladogram. In the Archaeorhynchus paper, Yanornis and Yixianornis do not form a monophyletic clade for example - but with what support me likes to know? They are apparently close, but being stem Ornithurae, "close" can mean anything from "part of a distinct clade" (Yanornithiformes in this case) to "subsequent stem divergences" (which can actually make them de facto closest relatives without being sister taxa in the strict sense - the 2 branches of a dichotomy that is).

Given that the new findings regarding the origin of some human genome sequences suggest that hybridization was continuing for (IIRC) 1.5 MA after the human - chimp split, one wonders whether the dichotomy concept is worth anything at all... if a cladogenesis event takes longer on average than the average time between cladogenesis events, the assumption that dichotomy is a feasible representation for phylogenies even just "more often than not" falls to pieces. (Personally, I prefer to err on the side of caution and remain equivocal about the exact branching pattern around a clade's initical divergence. That recognizable clades exist and can be supported by cladistic methods is fair enough and a lot of undisputable information regarding evolution of lineages can already be drawn from this. Add paleobiogepgraphy and you're set for a lot of insight already; no need to be controversial in many cases actually... And in any case, no matter how limited the fossil record may be - and major radiation seems to involve few major lineages making up 50-95% of the resultant diversity, and the rest consisting of as many "waifs and strays" as needed. This pattern is found over and over again in Neornithes, and I'd guess tit holds true for all theropods at least, in the absence of a megaextinction.) Dysmorodrepanis 16:22, 10 January 2007 (UTC)

Well, perhaps we should see a cladistic analysis as a special kind of dialectics that shows us what is the full content of the material proof. And if we define the date of the split as the last occurrence of hybridisation we solve at least part of the problem. The real issue of course being species variability. ;o)--MWAK 18:14, 10 January 2007 (UTC)

Good Books on topic

Hi everyone. Im trying to find a good, recent book on the topic of bird evolution and their relationship with Dinosaurs. By recent, i was hoping for something that referred to the feathered dinosaur findings in China.

Anybody know any such books?

As it happens, Luis Chiappe has just published Glorified Dinosaurs: The Origin and Early Evolution of Birds. A must for anyone truly interested in the subject. But it isn't exactly cheap. See: http://www.unswpress.com.au/isbn/0868404136.htm

More technical is his recent Mesozoic Birds: Above the Heads of Dinosaurs, See: http://www.amazon.com/exec/obidos/ASIN/0520200942/qid%3D1028799085/sr%3D11-1 and it is accordingly even more expensive

University of California students may have access to an online version. I recommend this book also as a meta-work, because it represents an earlier stage of the debate. If there is a book starting with which the theropod issue was sorted out for good, it is this. Chiappe's only the editor here; the volume is composed of analyses of paravian taxa from all over the world by many of the great names in the scene. It still is the only comprehensive source for many obscure forms. Dysmorodrepanis 10:34, 6 February 2007 (UTC)

Also Gregory Paul's Dinosaurs of the Air is still a very useful work. As the above link shows, you can order it together with Mesozoic Birds at a reduced price :o).--MWAK 08:34, 6 February 2007 (UTC)

Move this article to "Bird origins"?

The title as it is seems almost un-evolutionary to me, and certainly not particularly encyclopaedic. I propose moving it to "Bird origins"; which would sound more encyclopaedic, and provide a better context. --John.Conway 18:29, 29 April 2007 (UTC)

Oppose because it just ain't that simple. The problem is that it increasingly seems as if "bird" is a form taxon with no phylogenetic merit. But I am presently collecting material for some article "Phylogeny & systematics of modern birds" or whatnot here and this would probably be more like where you're hinting at with the proposal.

It is all but impossible at present to say whether a monolithic "origin of birds" actually existed. What we can say quite well already (compared to 15 years ago) is a lot on the origin of Neornithes. Basically that's what my material collection is about; missing stuff that can't go on any existing page at present. Dysmorodrepanis 23:16, 29 April 2007 (UTC)

"Bird" is Aves on the Wikipedia, and the bird article is about a monophyletic clade (Archaeopteyx + Neornithes). In any case, the title of this article already has "bird" in the title. "Bird origins" would reflect the precise evolutionary nature of the article, rather than the vaguely weasely "connection". --John.Conway 07:41, 30 April 2007 (UTC)

"the bird article is about a monophyletic clade (Archaeopteyx + Neornithes)". - have you followed the discussion about doi:10.1126/science.1120331, namely the author's conclusion,

"We are not aware of any derived character shared by Archaeopteryx and Confuciusornis that is not also present in the deinoychosaur Microraptor. However, and as noted above, Microraptor shares derived characters with Confuciusornis that are absent in Archaeopteryx, and we thus do not agree with Corfe and Butler's comment that 'the hypothesis of a polyphyletic Aves is no better supported by available data than that of a monophyletic Aves.'"

? You can always make a clade out of a crown and a stem taxon, but if this clade makes sense is another question entirely. As for the phylo-taxo definition of Aves, we have at least 2 major opinions and altogether, the weight seems towards learning excluding Archie from Aves. You might want to add the refs to Bird#Evolution_and_taxonomy. Source for the + Archie definition is Sereno's "Taxon Search" (I changed it to "traditional" because most authors currently tend to avoid having to define Aves altogether except in dedicated papers). For the others, see the source code.

"the precise evolutionary nature of the article" - ehm, the article is about 1/3 "Debate".

We do have Bird evolution BTW. Dysmorodrepanis 09:33, 30 April 2007 (UTC)

I'm sorry, I don't see the relevance of this to the name change of this article. "Bird origins" sounds more encyclopaedic, and reflects what should be treatment of the whole subject, rather than a angle on a subject. And, as I pointed out: "bird" is already in the title. I wouldn't object to a merger with bird evolution, although I think it may get rather long.

And my "precise evolutionary nature of the article" was meant to refer to its subject matter, not its actual content (which is quite messy at the moment). --John.Conway 09:53, 30 April 2007 (UTC)

Then it seems to be a mere matter of connotation. "Origin" raises my hackles, it's the weasel word par excellence for me and I tend to avoid it. This is because I came across the term most often (in a context also including evolution) via talk.origins, and there it can even mean young-earth creationism. Your experience obviously differed.

To throw one more in, we also have feathered dinosaur, and any Neornithes evolution/phylogeny article will also become too long to include it as a chapter. So we're already dealing with three articles and by the end of this year (I hope) there will be at least one more. And I totally agree with you that this is a mess and needs to be sorted out (In fact, I was against this here article in the first place ;-) ). BUT I think it should be done in a unified fashion, and ideally should be discussed and agreed upon in both Birds and Dinosaurs wikiprojects, not piecemeal article-by-article.

So don't understand my objections as this move proposal going too far. On the contrary: a lot more needs to be moved about and smoothened out than just this article. I am all in favor of restructuring the entire topic's associated pages. But for that, we'd better get all the birds and all the non-avian dino people together to decide.

Altogether, I see your point now. As it's a matter of taste more than anything else, I clarify my opinion to Oppose, but neither firmly nor in principle - if a lot of people support the move, I'll gladly go with it. Dysmorodrepanis 10:57, 30 April 2007 (UTC)

For me the connotation is with The Origin of Species. "Origin" to me seems to fit nicely with evolutionary thought: there was an original bird, and it gave rise to all the other birds. Connection is far vaguer, it could mean just about anything.

I would like to get this sorted out the consensus way, I will suggest the following at both projects: that we work on the Bird evolution article, with a section on origins or evolutionary origins if you'd prefer, pointing to a main article on the subject which would be a merger of this one and feathered dinosaurs, and add a discussion on the origin of bird flight. --John.Conway 11:35, 30 April 2007 (UTC)

Well, I have two points to make:

1. "Bird origins" or even better "Origin of birds" is preferable because it is less POV. Changing the title is but one of the steps to take to make the article more NPOV. As it is now, it tries to present the BAD position as established fact, but at the same time is argumentative and defensive about it, as if this fact isn't as generally accepted as one would like. The reason of course being that there is indeed a BAND position, held by scientists who are, whatever one may think about their level of scholarship (and I personally agree it is low), not entirely discredited. The best way to attain the necessary neutrality and detachment would be to structure the article along the historical development of thought about bird origins, a subject after all most interesting in its own right.
2. Merging this article with feathered dinosaurs seems very infelicitous. Firstly, this would by necessity make the title even less neutral about the subject of bird origins. The next objection would be that it would impede making the history of thought about bird orgins the main structure, unless we treat the subject of feathered dinosaurs as some subset of it. But the developing insights about bird origins have shown us that this seemingly most birdish of characters, the feather, has likely not evolved in a context of flight and that protofeathers might have been very widespread. So it is a subject that has outgrown that of bird origins and thus merits its own treatment. Should we however make the origin of birds a subset of a larger feathered dinosaurs article, the birds will completely dominate it and give a quite teleological suggestion to the casual reader (the vast majority) as if flight was the inevitable outcome of feathers.--MWAK 06:30, 1 May 2007 (UTC)

First point, I agree — though I think the article should treat the theropodan ancestry of birds as pretty much established fact now, reporting on the alternative in a historical manner. I think anything else would be undue weight. And yes, Origin of birds is a better title.

Second, I agree here too, I changed my mind about the feathered dinosaurs article last night. Good point about the impression of teleology. The article's useful, and should stay. --John.Conway 11:09, 1 May 2007 (UTC)

I agree that the current title is pretty bad. I think merging this article into Bird evolution is the best option right now. I think one thing making this article appear longer than it is, is the almost listified section on shared anatomy between birds and non-avian dinosaurs. This should be condensed a bit, and the resulting merged article won't be longer than many other articles with a lot of ground to cover, like Dinosaur and Bird themselves. Bird is also a FAC at the moment, and a good, comprehensive Bird evolution article could provide material for a better summary of the evolution section in the main article. Dinoguy2 12:35, 1 May 2007 (UTC)

Merging with Bird evolution is of course a possibility, but it seems to me to be a retrograde step. If both articles would still be very short it would have been practical, but only as a temporary situation. As the subject of bird evolution is so exceedingly large and contentious, specialised subarticles would have to be developed in the end — and now we already have one, so why not keep it? :o). Besides it has generated so much interest in the past (within the field of evolution only surpassed by the origins of our own species) that it has become a sort of socio-cultural phenomenon in its own right, best with its own approach.

I agree with John Conway that it has to be avoided to give the impression that the BAND position is somehow equal to the BAD one in the theoretical and empirical support for it. Within a historical treatment it should be possible to convey to the reader the precise grounds on which the vast majority of paleontologists decided to change its opinion, giving the BAND exactly the weight due to it, as a surpassed theory.--MWAK 15:07, 1 May 2007 (UTC)

I'm going to be bold, and move this to "Origin of birds". We can discuss a merger with bird evolution from there (I'm mildly opposed to the idea, because I think a long article can be made out of this, and they are slightly different subjects). --John.Conway 15:11, 1 May 2007 (UTC)

BCF

There is way too much on BCF here. As it hasn't even been published in the scientific literature, it's been given undue weight. Does someone who's familiar with it want to cut it down in a sensible manner? I don't really want to do it myself, because I know next to nothing about it. --John.Conway 15:25, 1 May 2007 (UTC)

Well, it's a relevant subject in this context so it must be treated. If we treat it, we should do it adequately, so that the reader is able to understand the issue. Cutting down would prevent this. Whether a subject is given undue weight is rarely determined by the absolute quantity of text dedicated to it. Decisive is the qualitative presentation of a position; as it is clearly indicated here BCF has found little support, no undue weight is given in that respect. True, the section on BCF has a level of depth the others lack. But the way forward is to increase the conceptual coherency and empirical adequacy of the other sections, not to reduce the coherency of this one.--MWAK 16:21, 1 May 2007 (UTC)

I disagree with it's inclusion. As far as I know, BCF has never been published in scientific literature, and has only one adherent (George himself). This is clearly undue weight. It should be moved to an article of it's own. —John.Conway 17:52, 17 May 2007 (UTC)

If BCF had mere notoriety value, you would be right. I would like to keep it in because of another reason: its usefulness for a conceptually coherent treatment of the subject of bird-dinosaur relations. You ideally would have to cover the logical position that flight evolved in a very basal form. Now it happens to be that someone has indeed conceived a hypothesis about this possibility, so you mention it. Why deny ourselves the opportunity to combine metatheoretical adequacy with historical exactness? :o)--MWAK 15:02, 18 May 2007 (UTC)

Mere notoriety value is all it has. Actually not even that -- I hadn't heard of this flake until I came across the article. You only have to cover "the logical position that flight evolved in a very basal form" if there's an a priori reason why this might be true, and there isn't. In this subject there are no a priori reasons for anything. You have to base your hypotheses on evidence, and there isn't any for this one.

Anyone can propose a hypothesis about anything. That doesn't make it worth including. BCF does not answer more questions than it raises, it doesn't explain anything otherwise inexplicable by simpler hypotheses, it makes excuses for failing at the only new prediction it makes, and is accepted by no one but its inventor. It's a fringe theory that doesn't belong in a serious article.

I'm sorry, but "metatheoretical adequacy" is very much of a reach. Metatheory of any variety belongs in a philosophy of science related article, not in a topical scientific one. Wherever it belongs, it's not here. I'm cutting it. TCC (talk) (contribs) 21:14, 26 May 2007 (UTC)

I've moved the information to George Olshevsky. Apart from disagreeing with you on the function of metatheory in science :o), I wonder why — if BCF should be barred from a serious article — the BAND-position, the empirical support for which is incomparably worse, gets its articles published in Science. It's a funny old world ;o).--MWAK 13:47, 30 September 2007 (UTC)

I dunno, it seems to me that BAND and BCF are pretty similar. Both use Longisquama as a bird 'ancestor', it's just that Olshevsky sees it as more derived than phytodinosaurians while BANDits see it as a less derived archosaur. BCF also shifts all theropods as Longisquama descendants rather than just maniraptorans as in BCF, which is a relatively minor difference... Dinoguy2 13:54, 30 September 2007 (UTC)

Well, no: BCF and MANIAC are of course vastly different. MANIAC makes the, almost completely uncorroborated, claim that the Maniraptora would be outside of Dinosauria. BCF however, accepts any outcome of cladistic analysis; it just makes explicit (or better still: it is simply the "explicitation" of) the possibility that any node ancestral to birds might have the morphology of a small arboreal form with integument, combined with a scenario about the kind of nodes for which this possibility is plausible. Where a particular, poorly known, form is placed within the cladogram is of secondary importance. The number of serious cladistic analyses including Longisquama being at present zero, Olshevsky felt free to speculate; also he is in agreement with Jones that a furcula is present. But if Longisquama is a lepidosaurian, so much the better for BCF if its scales were homologous with featheres: "birdiness" would be even more basal :o).--MWAK 19:11, 30 September 2007 (UTC)

Discussion copied from talk pages

Per User:John.Conway's request on the WP:DINO talk page, I am copying a discussion on improvements to this article below. Any further discussion is absolutely welcome! Sheep81 09:45, 21 June 2007 (UTC)

I was also wondering if you want to work together and clean up Origin of birds... it's a pretty long article already, but I bet we could get it featured... would be cool to have a non-genus article featured eh? Sheep81 07:28, 14 June 2007 (UTC)

Hey, cleaning up Origin of birds is a great idea, I'll look through my stuff and see if there's anything I can expand on or add later tonight, do some further cleanup if needed, etc. I agree with you on the Velociraptor taxonomy stuff. I'll see if I can summarize the important points and merge the rest into Dromaeosauridae. Dinoguy2 08:59, 14 June 2007 (UTC)

All right, I have been reading through OoB, and a couple things pop out at me. There is almost no mention of phylogeny whatsoever! Also, the article is one-sided, as it should be, since the evidence is one-sided, but to a fault. Feduccia, Martin, and Lingham-Soliar are not even mentioned! There should at least be a section addressing the BAND argument, I think. Needs copyediting and obviously a lot of refs are needed too (look at all the citation needed tags you put in). Overall, I don't think it reads very encyclopedically, so maybe we should even rewrite certain parts. Thoughts? Sheep81 07:33, 15 June 2007 (UTC)

A lot of the "Features" subheadings need quite a lot of expansion as most are one sentence long. Furculae should probably move up to that section as well. We are bone guys, there should be a lot more about the skeletal similarities than there is. Sheep81 07:39, 15 June 2007 (UTC)

Sorry I haven't had much time to work on this, but I agree with your points on my talk page. Bone similarities are the key feature we should focus a lot of the article on. There's quite a bit of this on Deinonychus and Archaeopteryx that could probably just be lifted and modified into something more general... Dinoguy2 09:28, 15 June 2007 (UTC)

I'm happy to help, just give me a few weeks to do some reading around the subject, m'kay?Sabine's Sunbird talk 10:46, 21 June 2007 (UTC)

Great! Not a huge rush, I may touch up a few things in the meantime though. Sheep81 12:21, 21 June 2007 (UTC)

"Ontology"?

The section on digit homology says: "However, with no ontological basis to definitively state which digits are which on a theropod hand, the labelling of the theropod hand is inconclusive." The page on Ontology says that ontology is "the study of being or existence, which forms the basic subject matter of metaphysics." Am I missing something here -the philosophy of metatarsals, perhaps? :) - or is that just the wrong term? (I don't think Ontology (computer science) applies, either) --Jude 23:21, 21 June 2007 (UTC)

Probably ontogeny. Sheep81 23:46, 21 June 2007 (UTC)

Ohhh. Alright, thanks!--Jude 00:58, 22 June 2007 (UTC)

Features linking dinos and birds

This section curently has multiple one line subsections. These subheadings can probably be eliminated and made into one section (with teh self referencing bit at the begining removed.Sabine's Sunbird talk 02:04, 22 June 2007 (UTC)

We could also combine the smaller subsections into larger ones. Like feathers, skeletal, soft tissue, and behavioral similarities. Or something to that effect. There is going to be a lot of information added to that section if we are thorough, so I feel some subdivisions would help to make it more readable in the long run. Sheep81 07:10, 22 June 2007 (UTC)

New lead

I don't think the current lead is written very encyclopediacally, if that's a word, and I also don't think it summarizes the article very well at all. I've sketched out a new lead section which I'm posting below. Sheep81 08:02, 22 June 2007 (UTC)

The origin of birds has been a contentious topic among scientists for many years, but more recently a scientific consensus has emerged which holds that birds evolved from theropod dinosaurs during the Mesozoic Era. The relationship between birds and dinosaurs was first proposed in the nineteenth century after the discovery of the primitive bird Archaeopteryx in Germany, and has been all but confirmed by recent finds of feathered dinosaur fossils in the Liaoning Province of China. In the phylogenetic sense, birds are modern dinosaurs.

Birds share hundreds of skeletal features with dinosaurs, especially with derived maniraptoran theropods like the dromaeosaurids, which are usually thought to be their closest relatives. Although harder to identify in the fossil record, similarities in the digestive and cardiovascular systems, as well as behavioral similarities and the shared presence of feathers, also link birds with dinosaurs. The ground-breaking discovery of fossilized Tyrannosaurus rex soft tissue allowed comparison of cellular anatomy and protein sequencing of collagen tissue, both of which provided additional evidence corroborating the dinosaur-bird relationship.

Few scientists still debate the dinosaurian origin of birds, although some suggest descent from other types of reptiles. Even among those who support dinosaur ancestry, the exact phylogeny of theropods and early birds remains controversial. The origin of bird flight is a separate but related question for which there are also several proposed answers.

I would appreciate any comments or criticism. Feel free to edit the above as you see fit, if you think you can improve it (probably not that hard). Sheep81 08:02, 22 June 2007 (UTC)

I think it's a big improvement. I say stick it in and we can edit it in place. —John.Conway 12:15, 22 June 2007 (UTC)

Thanks MWAK for your edits to the lead! I think, with some exceptions, they made real improvement. I did revert some of them though, so I'll explain here. First, you added "other" to the phrase "birds evolved from theropod dinosaurs". I think the "other" is unnecessary, first, because the sentence was quite true on its own before the addition, and second, because it is redundant and goes without saying. Birds obviously evolved from other theropods -- they couldn't very well evolve from themselves, right? Second of all, cladistics didn't show that birds evolved from dinosaurs. John Ostrom showed that very well with comparative anatomy back in the early 70s before cladistics really came into vogue. Cladistics is one line of evidence among many, and certainly not the first, that supports the hypothesis that birds evolved from dinosaurs. So I reverted that part. Third of all, you edited the first sentence of the second paragraph to read "Birds show hundreds of skeletal features that they share only with dinosaurs" which isn't quite true... while that is true of many, some of these features are also found in other groups. it's the fact that so many of these features occur together in dinosaurs and birds that leads us to believe they are related. So if you take out the "only" you are left with "Birds show hundreds of skeletal features that they share with dinosaurs" which is more concisely written as "Birds share hundreds of skeletal features with dinosaurs." Finally, the rewrite of the first sentence of the third paragraph also added unnecessary length to the sentence without changing its meaning, so I reverted that back to its original form. Thank you very much for your edits, I hope you understand my reasoning above. Please don't hesitate to comment. Sheep81 09:43, 25 June 2007 (UTC)

I shall :o):

1. Yes, "other" is redundant, given an adequate knowledge of evolutionary theory. Sadly, not only does the average reader not possess this knowledge — even biologists still work with paraphyletic taxa. So it would still be functional to make the fact that birds are theropods explicit.
2. Indeed, Ostrom did revive the old hypothesis. But the comparative method he employed still offered a lesser empirical justification. Alternative hypotheses were still taken very seriously around 1980. So cladistics need to be mentioned, just to make clear why we are so very sure. It is not simply "a line of evidence" among others but the dominant overarching scientific method in the field, into which all other evidence must be merged to be valid.
3. Those synapomorphies that are not shared with other groups, are not :o). True, for a certain topology, others may well be important. However this is less relevant than the fact that the sentence as it now stands is very deceptive. I too share hundreds, yea tens of thousands, morphological features with birds, yet I am not as closely related to them as a non-avian theropod is. Only a tiny minority of the features that birds and other dinosaurs share, are synapomorphies for the various dinosaurian clades birds belong to. If you could find an elegant way to express this without the simple expedient of mentioning only those features that are shared with other dinosaurs only, please do. In the original lead section I had placed a more cumbersome explanation.
4. The first sentence of the third section is now illogical. Either it implies that you can suggest the direct descent of birds from non-dinosaurian reptiles without contending the descent from dinosaurian reptiles, or the "some" are in fact belonging to the "few", in which case the "although" is incorrect. I propose this change: "Although some scientists suggest descent from other types of archosaurian reptiles, only a very few debate the dinosaurian origin of birds in this way".
5. You also reverted my changes about the importance of the Chinese fossils. While they have done much to bring the issue to the public eye, they have in no way been decisive. Of course they "confirmed" but only that: they did not all but ascertain. We did't need them for that. Such is the power of cladistics :o).--MWAK 12:46, 25 June 2007 (UTC)

No we definitely needed them. A method such as cladistics which relies on interpretation of evidence can never prove, only support. Cladistic studies of morphology will usually recover monophyly of loons, grebes, and Hesperornis, and it seems that little could be farther from the truth... What is usually required these days is an evaluation of total evidence (fossil, molecular, and paleobiogeographical data) according to cladistic methodology. If you choose taxa from crownwards (i.e. towards extant birds) and nest fossil forms with these, you'll get a different phylogeny than when you analyse the problem from stemwards. Why cladistics has superceded phenetics as an analytical technique is mainly because character grades are more frequent than homoplasies (Archaeopteryx to Neoaves are a wonderful grade, which means they cannot be analyzed phenetically if one hopes to achieve good results). But that does not mean that the latter are nonexistent, which is the underlying assumption when you do cladistics according to parsimony. Dysmorodrepanis 16:52, 25 June 2007 (UTC)

This is quite a different issue. Allow me to answer some of your points:

1. We didn't need the Chinese fosils to show that birds are theropods. For this the fossils and other data acquired when Huxley wrote his article (among which one exemplar of Archaeopteryx, one of Compsognathus and some crocodile) suffice.
2. All methods rely on an interpretation of evidence. Cladistics of course does not provide raw data but makes us understand what is the exact content of these data. By doing this it most certainly "proves" a certain phylogeny. That there has been no prior posing of a resultant phylogeny as a hypothesis to be tested, is utterly irrelevant.
3. Molecular data are obviously cladistically analysed too. There are problems of integration but the eventual solution will result in again a cladistic project.
4. The primary method of analysis should be cladistics. It should be the other methods that are supportive of it, not vice versa. Admittedly twenty years ago the actual situation did as yet not conform to this imperative, bur science progresses :o).
5. I appreciate your ironic hyperbole about Hesperornis, but how, pray, could you be so very sure about the relationship between grebes and loons? As probably the birdies didn't tell you themselves, your doubts could only be founded on...not phenetics but some subjective and inexact application of "weighted" characters. And you could be quite right in that and would be a fool to abstain from it for some dogmatic reason. But this must be an incidental correction, a piece of wise, informed speculation qualifying the cladistic mainframe. And when the cladistic project is just beginning in some group, we might need an entire shell of it supporting the growing cladistic core. But cladism is the core, not the support.
6. Cladistics superseded phenetical methods because it was more exact. Character grades are rather rare (evolution is mostly chaotic) but cladistics can better deal with homoplasies as it isn't as easily fooled by symplesiomorphy.
7. Yes, taxon and outgroup choice can strongly influence the results. But by making these choices explicit, cladistics allows for improvement.--MWAK 20:04, 25 June 2007 (UTC)

True and well put. What I pointed at was that there is some tendency (just as with hyping everything that has "genes" in it in other fields) that conclusions are hyped by inexperienced users because "they're cladistics". People who see a single consensus tree without support values and think "oh, this is it". Simple fallacy. Todays, almost everything is cladistics, and that's good, because cladistics is, for practical purposes, the most sound concept science has been able to come up with. But every now and then, one finds reviews of papers on WP by people who haven't understood that a tree gained from a PAUP* analysis or whatnot is simply the best the analysis, in its own limited scope, could come up with (sometimes, I hear - but that's rumors, albeit by people who should know - PAUP*-runs are not even reproducible, which makes them, strictly speaking, not "proper" science). So any proposed tree must be weighed against alternative proposals. This is not a problem when you have total-evidence analyses, or when the trees are uncontroversial. In some cases (in the scope of this article more often than in crown Aves), this is not the case. And until there are the required analyses, all we can do here is discuss, and remark. Not speculate unduly; there's a fine line between discussion and OR (for me, it's basically "might" vs. "is"). Ideally, some budding young scientist will even read the WP and do the analyses that might be remarked upon as "missing" in an article. No basal Aves examples that spring to my mind immediately, but I could discuss to what the Bearded Reedling should be compared to find its place in the tree :)

As regards loons and grebes, well, the total evidence fits a grebe-flamingo relationship amazingly well. Basically, if you look at the issue from that angle, all the data suddenly falls into place and makes sense. Bones. DNA. Parasites. Biogeography. Of course, nobody had been considering such a relationship worthwhile of research until the last years... but by now, the Mirandornithes seem one of the most amazingly robust new clades of Neornithes.

Loons? Anyone's guess. Close relationship with penguins has been proposed, but biogeography strongly weighs against this (the equatorial gap makes no sense a all), although the Maastrichtian penguin ancestor seems indeed to have been somewhat like a loon in morphology (see also Polarornis). My best guess would be somewhere in the "higher waterbirds": storks, cranes, pelicans, tubenoses. But where? This group itself is tangled enough as it is, and the traditional orders are almost all paraphyletic: tropicbirds are no Pelecaniformes, kagus are no Gruiformes, etc. Which is incidentially a nice case in point: scores of "consensus" (in the scope of the respective studies) trees have been published for the "higher waterbirds", but there is no accepted consensus phylogeny. Though Mayr et al. are busy working on it. Expect some interesting new data in J.Vertebr.Paleontoll later this year... Dysmorodrepanis 17:00, 30 June 2007 (UTC)

This is a response to MWAK's first list of points, which were in response to me, not his second list of points which were in response to Dysmorodrepanis.

1. I see your point that most people don't understand the concepts of monophyly and paraphyly. However, I don't think the sentence is wrong as-is, and I do think it still gets its point across in a more concise and less redundant manner.
2. You're right, of course, the lead which I wrote places far too much emphasis on the Chinese fossils when the matter was honestly settled long before they were discovered. I'll add a bit more on phylogeny and comparative anatomy there.
3. I'll fix the first sentence of paragraph two to emphasize synapomorphies. I think I can do it by adding only one word. We'll see.
4. I'll rewrite the first sentence of paragraph three as well. It could be a little clearer.
5. See #2.

Sheep81 05:31, 26 June 2007 (UTC)

I think your last changes were excellent and remove any objections from my side.--MWAK 11:13, 27 June 2007 (UTC)

Copy editing

As per my suggestion on the WP:DINO talk page, I've moved a bunch of cited text from the main Dinosaur article into the text here. I recognised the text was practically the same from when I revamped the Dinosaur article before it got featured, so it wasn't too ahrd copying it over. I've added a few new sections, and have also merged a few others. Anyway, I hope this helps somewhat & I'll be doing some more work on the article later. Unless JC doesn't want me near here, despite my good intentions. Spawn Man 06:38, 27 June 2007 (UTC)

Anatomy source

Check out http://cas.bellarmine.edu/tietjen/Evolution/Dinos/figure_4.htm - I wouldn't be so certain about the pygostyle (I need to find the reference again that suggested that this feature evolved at least thrice, once in non-avians and twice in birds), but altogether, it's a good summary to bolster the skeletal features list. Dysmorodrepanis 17:03, 30 June 2007 (UTC)

But beware: Sereno wrote this based on the data known ten years ago.--MWAK 05:01, 1 July 2007 (UTC)

This should be merged with evolution of birds Kabain52

No, this is specifically about the origin of birds. Birds did a lot of evolving after their origin. Sheep81 23:47, 22 July 2007 (UTC)

Reproductive age article

Here's for when someone gets around to it: the Erickson et al. article on age of nesting theropods.

Enjoy! J. Spencer 02:41, 27 July 2007 (UTC)

New (kinda) paper

XU Xing, 2006: Feathered dinosaurs from China and the evolution of major avian characters. Integrative Zoology: vol.1, n°1 (03-2006): p.4-11. Mainly discusses feather evolution, which is a topic where mistakes are easily made: today, one would think "avian feathers" when thinking "feathers", but in the Cretaceous, this was not quite true... there was everything between protodown and avian flight feathers, including peculiar derived stuff not found anymore today, such as symmetric wing feathers (which possibly never evolved in the bird lineage proper but certainly at least once among their relatives). Dysmorodrepanis 14:14, 2 December 2007 (UTC)

George Olshevsky's "Birds Came First" hypothesis links here

I see no mention of a "dinosaurs arose from birds" hypothesis in this article! This troubles me because the link therefore overpromotes Mr. Olshevsky.130.86.14.89 (talk) 20:57, 21 December 2007 (UTC)

The fact that BCF is not mentioned here, overpromotes it? Pray, explain.--MWAK (talk) 08:25, 22 December 2007 (UTC)

I think... going wayyyy out on a skinny little limb here... maybe he means that because typing in "Birds Came First" redirects to this article, that it makes it seem like Olshevsky came up with the whole thing? Maybe? Sheep81 (talk) 08:34, 22 December 2007 (UTC)

I hadn't noticed that someone had messed up the George Olshevsky article pretty badly :o). I've repaired the damage.--MWAK (talk) 08:39, 22 December 2007 (UTC)

I redirected "Birds Came First" to Olshevsky's article. Since he's the only proponent, it seemed like a reasonable redirect. Sheep81 (talk) 08:47, 22 December 2007 (UTC)

You beat me to it :o).--MWAK (talk) 09:04, 22 December 2007 (UTC)

Origin of birds is collab for Jan 08

Nominated December 7, 2007;

Support:

1. Spawn Man (talk) 10:49, 7 December 2007 (UTC)
2. Sheep81 (talk) 03:02, 10 December 2007 (UTC)
3. cheers, Casliber (talk · contribs) 03:38, 10 December 2007 (UTC)
4. Firsfron of Ronchester 16:23, 10 December 2007 (UTC)
5. Dinoguy2 (talk) 17:20, 10 December 2007 (UTC)
6. ArthurWeasley (talk) 06:10, 20 December 2007 (UTC)

Comments:

• It's nearly there and would benifit from being nominated. :) Cheers, Spawn Man (talk) 10:49, 7 December 2007 (UTC)
• Yeah, most of the info is there already, and if we can just rewrite some sections and agree on a way to reorganize it so it doesn't seem like a bunch of random subheadings, this could be a cinch for FA. Sheep81 (talk) 03:02, 10 December 2007 (UTC)
• Striking while the iron is hot (with bird at FAC too, agree, and a change from individual genera. cheers, Casliber (talk · contribs) 03:38, 10 December 2007 (UTC)
• Have some material I could probably use to contribute. Dinoguy2 (talk) 17:20, 10 December 2007 (UTC)
• Definitely important! ArthurWeasley (talk) 06:10, 20 December 2007 (UTC)

---

Cladistic diagrams?

If we could toss in three or four simple cladistic diagrams comparing and contrasting the various theories, I think that this would be quite helpful to many readers. -- Writtenonsand (talk) 14:04, 4 January 2008 (UTC)

Some taxa that could/should be in there:

• Aves
• Theropoda
• Sauropoda and Ornithischia (to show dino diversity. Dinos might also be non-monophyletic in some non-mainstream models)
• Crurotarsi and Crocodilia
• Archosauria
• Diapsida
• "other reptiles"
• Perhaps Pterosauria for curiosity/completeness.

Dysmorodrepanis (talk) 03:44, 7 January 2008 (UTC)

Refs

I'm not a bird person, but I was just working on the Feathers sub-subsection in Dinosaur, and added some refs dealing with Feduccia that may be useful here. J. Spencer (talk) 03:51, 6 January 2008 (UTC)

Who said you could touch something with feathers, you ornithischian-loving maniac? :) Sheep81 (talk) 20:30, 7 January 2008 (UTC)

Okay collaborators, let's collaborate

I have ideas, oh yes, ideas.

Firstly, I think the article desperately needs a phylogeny section, to put birds in the proper context. Here's how I am thinking to organize it right now.

• Lead
• Research history (with a new name?)
• Phylogeny
• Features linking birds and dinosaurs (with a new name)
  • Skeletal
    • Skull
    • Vertebrae
    • Limbs
  • Feathers
  • Soft tissue and physiology
    • Respiratory system
    • Digestive system
    • Reproductive system
    • "B-rex" proteins
  • Behavior
    • Brooding
    • Sleeping posture
    • ???
• Debates
  • Origin of bird flight (including secondarily flightless dromaeosaurs)
  • Digit homology
• References
• External links

Thoughts? Sheep81 (talk) 05:08, 11 January 2008 (UTC)

Also, I assume this article pretty much just leads up to Archaeopteryx and no further, there being another bird evolution article to describe what happened after that. Is that sensible or do some of the early bird radiations need to be described here too? Honestly, if we were to improve this article, the bird evolution article, and say, feathered dinosaurs to FA or GA status, would that be a cohesive and comprehensive enough group of articles for a Bird Origins and Evolution featured topic? Sheep81 (talk) 05:19, 11 January 2008 (UTC)

If you get the layout of headings correct, then everything goes smoothly from there. That's the only piece of advice I can think of - I kinda hate birds... Unless they're in my butter chicken. ;) Cheers, Spawn Man (talk) 05:23, 11 January 2008 (UTC)

Sounds good. FT is a really good idea. I was musing, I guess bird evoloution and this one would be too big for one article wouldn't they... cheers, Casliber (talk · contribs) 05:33, 11 January 2008 (UTC)

Wrote a phylogeny section a couple days ago... no edits or comments on it yet. Anyone have an opinion on it or is it just as perfect as it could possibly be? (yeah right) Sheep81 (talk) 03:27, 26 January 2008 (UTC)

The article as a whole is shaping up nicely, but I can still see room for some improvements (and then for polishing, reducing duplication, etc. once the content is stable):

• Since most of the article quite reasonably is based on the idea that birds are dinos, it should dispose of the the remaining "not dino" theories after the section on Ostrom's work. I'm thinking of Protoavis and Feduccia's Longisquama-based theory, but there may be others (no, I don't mean BCF).
• But then it's most natural to follow with all the evidence linking birds to dinos.
• That means "Phylogeny" should at least follow the material on dino-bird links. I'm not a phylogeny enthusiast, and I suspect the general public aren't, so I'd prefer to see "Phylogeny" pretty late in the article. I also think there's a logical justification for that, since all possible doubts about the relationships and early evolution of birds should be got out of the way first.
• "Gizzard" should probably be dropped from the section on dino-bird links as the consensus now appears to be that dinos did not have gizzards. I recently read a study that concluded that sauropods didn't because the alleged gastroliths were too smooth and insufficient in quantity relative to the sauropods' size. If there is good recent support for gizzards in maniraptorans or in coelurosaurs generally, then "Gizzard" should be kept but should make it clear which dinos had gizzards. If "Gizzard" is dropped, Dinosaur should be updated to say this is a popular but obsolete idea.
• I'm not sure about "Furculae" in the section on dino-bird links, as it should have been covered as thoroughly as possible in the section on Heilman.
• Basal bird phylogeny is probably still uncertain. For example the discussion "Phylogenetic challenge to the coelurosaur hypothesis of bird origins" (earlier in this Talk page) rejected Kurochkin's phylogeny but the discussion opened up some other issues, notably that "bird" is "a form taxon (rubbish bin) if not all but restricted to Pygostylia or at least Ornithothoraces". Is there any suggestion in the literature that birds (in the wider sense of animals that are more similar to modern birds than to some fairly basal maniraptoran) may be polyphyletic? If not, I'm waiting for one, given the profusion of feathered and apparently flight-capable critters coming out of China.

BTW I agree with the decision that Origin of Birds should stop with something feathered that could fly. Bird takes up the story quite well from that point; Origin of Birds is long enough already; further evolution of birds is a topic for specialist paleornothologists to handle. Philcha (talk) 21:05, 21 March 2008 (UTC)

Your comments seem to show that having a phylogeny section early in the article would be very useful if it were combined with a reminder that with the word "bird" we can mean two things: a creature belonging to a certain monophyletic group or a creature having a certain morphological state. Perhaps even the very first chapter should clarify this issue. You wisely refer to the possibility that flight might well have originated many times — and if we should consider Microraptor to be "more similar to modern birds than to some fairly basal maniraptoran" (which conclusion would be hard to avoid) then the hypothesis that the "form taxon" "bird" might be "polyphyletic" (not a terminology combination I favour, you understand :o) would at present even be the ruling doctrine. But precisely for this reason the article cannot halt at the point where we reach "something feathered that could fly" unless it were certain that this something is basal in a clade that contains Neornithes and of which no member would be flightless, unless secondarily. Now, as indeed "[b]asal bird phylogeny is (...) still uncertain" it therefore should be treated here.

But there is another reason for an early phylogeny section: all the "evidence linking birds to dinos" only makes sense within a phylogenetic analysis. It only proves the link (i.e.: a phylogeny in which birds are within Dinosauria) when functioning as the emperical data processed by some phylogenetic method.

Gizzards should indeed not be mentioned here. Not because dinosaurs didn't have them, but because phylogenetic bracketing shows that it is most parsimonious to assume that all archosaurians had them — so the trait is, as far as we know, not a synapomorphy of Dinosauria. Should sauropod have lacked gizzards — I don't think there is any consensus on that — this would then be best explained as their autapomorphy.--MWAK (talk) 08:06, 22 March 2008 (UTC)

Hi, MWAK. I think I understand your comments, but they also illustrate why "Phylogeny" sections leave me cold. First they may be informative to people with your level of knowledge, but are of little use to non-specialist readers. For example I understand the basic concepts of cladistics (at a very basic level!), and I even have a vague understanding of "crown group" and "stem group" (but not the criteria for assigning a taxon to either), and I've edited a few paleo articles; so what chance has the non-specialist reader when these terms appear? Second, "Features linking birds and dinosaurs" helps to give the non-specialist reader a clearer picture of the subject (or both of them), while phylogeny does not (it only helps those who are already at least arm-chair paleontologists / biologists). Third, I confess to being a fairly rigid empiricist and I think that, as a matter of scientific principle, evidence (the synapomorphies) should precede theorizing (and yes, I know about paradigms).

Re dino / bird gizzards, the paper I found was recent (last 5 years), and that suggests there is reasonable doubt about gizzards in sauropods. Is there beyond-reasonable-doubt positive evidence of gizzards in maniraptorans (preferably) or a more inclusive group of theropods?

Re archosaur gizzards, first, can you point to good evidence? If so I'll happily include it in Archosaur. Second, "phylogenetic bracketing" and parsimony are just rules of thumb to guide further research or help generate testable hypotheses, they are not immutable laws of nature (if any of our current theories is such a thing, see "empiricist" above :-) ). There are enough examples of parallel evolution (about 40 x camera eyes for a start) to warn us against treating "phylogenetic bracketing" and parsimony as infallible guides. Fourth, "phylogenetic bracketing" would only apply if there was clear evidence of gizzards in preferably ornithodires or at least basal archosaurs, since according to current theories crurotarsan archosaurs are a sister clade of dinos and birds. And even then I'd also want to see evidence of gizzards in maniraptorans, otherwise I might have to consider the possibility that certain heterodox theories of the origin of birds might be true (Protoavis, Feduccia's), painful though that would be. Philcha (talk) 10:21, 22 March 2008 (UTC)

Oops, I almost forgot one of your points. Given the difficulties of defining "bird" unambiguously at any level more basal than neornithes, I agree that the stopping point of this article shoud ber "basal in a clade that contains Neornithes and of which no member would be flightless, unless secondarily" - one of the practical uses of phylogenies is in scoping articles :-) Of course we'd have to explain (very briedly!) the defining features of neornithes and our stopping point first, for the reasons I stated above. And some brave soul will have to consider writing 1 or more articles about the evolution of its sister groups (not me, I know nothing). Philcha (talk) 10:34, 22 March 2008 (UTC)

Well, the technical concepts are really all very simple and can easily be explained to the average reader. It just takes more space. The natural mistake to confuse the different issues of the origin of "birdiness" on the one hand, and of Aves on the other, should be pointed out immediately. Of course, in a popular science article it would be perfectly alright to make the reader aware of his essentialist bias by first tempting him into thinking that birds are dinosaurs, showing that some of the latter had feathers — and then shatter his illusion by making clear that they constitute very meagre proof because they fossilise so poorly and thus might be older than Dinosauria themselves. But this is an encyclopedia and such educational tricks are not allowed here. This example also shows one major flaw in your proposed arrangement of the text: the hundreds of tiny osteological features form the main body of scientific proof, yet cannot all be numbered. The reader would probably incorrectly assume that they are mere details. Another flaw is that similarity as such proves nothing: symplesiomorphies are invalid. How is the reader to understand this, unless some explanation has been given about what evidence matters in phylogeny? In short: you want to present phylogenetic evidence without making explicit that the evidence is phylogenetic.

As regards gizzards: I was referring to the fact extant Crocodilians have them. Phylogenetic bracketing might indeed generate new hypotheses — many phenomena do — but is in itself empirical evidence. This evidence then justifies a null hypothesis, to be deemed more probable unless contradictory evidence is presented. Any heterodox theory should obviously be considered :o), nut not be concluded to be more likely because of a lack of evidence for maniraptoran gizzards.

The main point of the stopping point is that there is little consensus on where it stops :o).--MWAK (talk) 13:56, 22 March 2008 (UTC)

Paravian phylogenies

Here's a partial list of recent published phylogenies which purport to show the position of Aves within Coelurosauria.

• Maryanska et al 2002 (oviraptorosaurs are secondarily flightless birds, with therizinosaurs sister group to birds) free download from APP
• Mayr et al 2005 (deinonychosaurs are secondarily flightless birds) free download from Science
• Turner, Hwang & Norell 2007 (deinonychosaurs sister to birds... shows entire Theropod Working Group cladogram of coelurosaurs) free download from AMNH Digital Libary
• Turner et al 2007 (deinonychosaurs sister to birds... latest in a long line of TWG papers... only shows Paraves) doi:10.1126/science.1144066 <-- not free yet, ask Sheep for a PDF if interested
• Senter 2007 (deinonychosaurs sister to birds) doi:10.1017/S1477201907002143 <-- not free, ask Sheep for a PDF if interested

Any important ones I missed? Are there any recent analyses supporting alvarezsaurs as birds? Sheep81 (talk) 05:48, 11 January 2008 (UTC)

Furculae

I'm surprised there's a "Furculae" subsection under "debates", since "Heilmann and the thecodont hypothesis" apears to lay the issue to rest. I suggest "Furculae" should be merged into the concluding part of "Heilmann and the thecodont hypothesis" - the two sections cite different sets of dinos with furculae, and it would be best to present all the evidence together. Philcha (talk) 20:12, 16 April 2008 (UTC)

I agree.--MWAK (talk) 05:13, 17 April 2008 (UTC)

Done.

I've used only 3 direct citations which I think are best value for money: Lipkin, C., Sereno, P.C., and Horner, J.R. (2007) lists just about everything else in its intro, makes the point that so far the only important theroopods lacking ossified furculae are Eoraptor and Herrerasaurus, and cites just about everything earlier; Carrano, M,R., Hutchinson, J.R., and Sampson, S.D. (2005) on Segisaurus, because it's poetic justice and cites just about everything earlier; and Yates and Vasconcelos (2005) for the prosauropod Massospondylus - and the 1st 2 are currently freely available online. But I've left the other material commented out immdeiately below in case any one thinks any of these add value. I've also left the previous "Furculae" section commented out below that.

Unfortunately I can't find even an abstract of Yates and Vasconcelos that's free & online. If anyone else knows of one, please add the url to the citation. Philcha (talk) 13:50, 17 April 2008 (UTC)

That's because it doesn't have an abstract, it's a brief note in JVP. I can send you a PDF if you want. (Yes I am still checking on ya'll even if I can't get online for very long recently.) Sheep81 (talk) 01:00, 18 April 2008 (UTC)

Also, while they were originally described as such, we don't know that Eoraptor and Herrerasaurus are actually theropods. There are many who believe they are saurischians basal to the theropod-sauropodomorph split and some who don't even think they are dinosaurs. Sheep81 (talk) 01:06, 18 April 2008 (UTC)

The alleged furcula shown in the image is a fractured rib or gastralia. The real furcula can be seen here: http://blog.everythingdinosaur.co.uk/rex_furcula_arrow.jpg 216.85.144.126 (talk) 21:45, 31 March 2010 (UTC)

bad DOI URI?

http://en.wikipedia.org/wiki/Origin_of_birds#cite_note-Harris2006-98 links to a 404.

Missing DOI: doi:10.1016/j.cub.2005.12.047 Referring Page: http://en.wikipedia.org/wiki/Origin_of_birds The actual DOI itself is 10.1016/j.cub.2005.12.047.

should link to http://dx.doi.org/10.1016/j.cub.2005.12.047 —Preceding unsigned comment added by 121.45.80.64 (talk) 15:55, 29 May 2008 (UTC)

ostrich

I noticed in the section entitled "features linking birds to dinosaurs", ostriches were cited as an example of birds having lost flight capabilities but retained feathers. Firstly, before I say anything, I want everyone to know that i am not trying to rant or start a fight. That being said, I understand, to a certain degree, Evolution as it occurs through genetics and so on, so I am curious. Perhaps someone can answer my question: if the ostrich at one point flew like any other bird, then, in order to now be flightless and adept at running great speeds, then would it not have had to develop strong running legs before it lost its feathers? I mean, wouldn't it have been killed by predators had it not already had strong legs? Which brings me to my other question, why would ostriches lose their flight in the first place, unless some huge mutation took it away, in which case it would most likely not have strong legs and therefore would have been eaten before it had a chance to pass along those traits? Is this the wrong place for such a question?Prussian725 (talk) 00:58, 13 August 2008 (UTC)

Strictly speaking this is the wrong place, as this page is for discussing possible changes to the article Origin of birds, and Wikipedia does not provide any general discussion forums. However every days supposed to be "be nice to others day" so here are some brief comments. I think it's very likely that ostriches' ancestor would have had to develop strong running legs before losing the power to fly. But this was not a big change, as most birds already have pretty good legs in relation to their size - the roadrunner is a famous example. This is not surprising as birds evolved from small, fast predatory dinosaurs, as described at Origin_of_birds#Origin_of_bird_flight - I favor the "from the ground up" theory of the origin of bird flight, in which birds' ancestors were effectively flightless roadrunners.

Loss of flight is pretty commmon in birds - see Flightless bird. Flight is actually quite a mixed blessing, since it brings some tough limitations with it: AFAIK the Andean condor is about as heavy as a bird can get and still fly; flying birds have to have light, fragile bones; there are limitations on their body shapes because of the need to avoid spoiling their balance in flight; it restricts the size of eggs and thus forces the young of most birds to be born helpless and vulnerable; etc. AFAIK most flightless birds evolve on islands free of large predators. Those that evolve on large land masses, as ostriches did, usually evolve some combination of speed and a vicious kick to protect themselves - the cassowary is pretty dangerous. In fact for about 60 M years years the phorusrachids were the top predators in S America. I hope this helps. -- Philcha (talk) 02:56, 13 August 2008 (UTC)

Yes, thank you very much for the comments! I am just glad I can ask these kinds of questions and not be attacked for it.Prussian725 (talk) 03:48, 14 August 2008 (UTC)

The diminished significance of Archaeopteryx

I've changed the first sentence to:

Archaeopteryx was the first and for a long time the only known feathered Mesozoic animal (or dinosaur, if one accepts the majority view that birds are modified dinosaurs).

I hope the addition of "Mesozoic" makes it more precise and clearer than the 2 previous versions:

• In "... the first and for a long time the only known feathered animal (or dinosaur, if one accepts the majority view that birds are modified dinosaurs)", the word "only" overlooks modern birds.
• "the first and for a long time the only known feathered non-avian dinosaur" assumes it was non-avian. That's a question of definition, and probably so messy that it should be avoided. -- Philcha (talk) 22:31, 16 September 2008 (UTC)

Popularity of the theory.

It is mentioned in the first section of the article that the theory was confirmed in the 1960’s. If it really was that long ago then why so many nature documentaries stated many times after that that the origin of birds are still a mystery? And why only recently that researchers are confirming that birds did originate from dinosaur? A new section needs to be made on this and or this topic needs some mention. Zorro444 (talk) 10:04, 28 September 2008 (UTC)

The first section says "all but confirmed in the 1960s", i.e. not completely confirmed. The rest of the article goes through theories of the origin of birds. The big obstacle to the dinosaur theory was that until the 1980s paleontologists overlooked or misinterpreted evidence that dinosaurs had furculae - it's in Origin_of_birds#Heilmann_and_the_thecodont_hypothesis.

Nature documentaries are not always reliable - sometimes they are poolry researched, and sometimes they omit important points to make time for more eye-candy. -- Philcha (talk) 12:23, 28 September 2008 (UTC)

Recent edit to lead re "theropod hypothesis"

A recent edit appeared to play down the fact "birds are theropods" is the view of the overwhelming majority of researchers. IO've edited to put it back in perspective. Some stuff I found while discussing the same proposition at Talk:Dinosaur may be helpful:

• Feathered dinosaurs, flying dinosaurs, crown dinosaurs, and the name “Aves” - heavy theory, but the bottom line is that they are.
• The Evolution of Dinosaurs (note "excluding birds for the purpose of comparison")
• Birds are Dinosaurs: Simple Answer to a Complex Problem - Feduccia admits "birds are theropods" is the consensus!), although he strongly disagrees with it. --Philcha (talk) 18:34, 15 June 2009 (UTC)

No, there is no consensus, see for example:

• James, FC and Pourtless, JA (2009) Cladistics and the Origin of Birds: A Review and Two New Analyses. Ornithological Monographs 66.
• DE Quick, JA Ruben (2009) Cardio-pulmonary anatomy in theropod dinosaurs: Implications from extant archosaurs. Journal of morphology, DOI: 10.1002/jmor.10752
• "Biomolecular Characterization and Protein Sequences of the Campanian Hadrosaur B. canadensis". Science. 324 (5927): 626–631. 2009. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

So, I will re-edit it to reflect that things are changing and that the 'consensus' in 2002 is maybe not longer that valid. -- Kim van der Linde ^{at venus} 19:55, 15 June 2009 (UTC)

The conclusions being drawn out of the Brachylophosaurus article are a lot to draw out of fragments of collagen (i.e. is it of great importance that fragments of collagen from two dinosaurs are closer than either is to birds?). J. Spencer (talk) 02:40, 16 June 2009 (UTC)

(also, we have no way of knowing the evolutionary pathway of the small known part of the collagen structures of Brachylophosaurus and Tyrannosaurus. There are multiple options: for example, the structures could be most similar in B and T because they are a shared characteristic inherited from the ancestor of B, T, and birds, but which was later changed by birds during their evolution from theropods [a plesiomorphy shared by the basal groups B and T]; as you proposed, they could be a special characteristic evolved in a group B + T {a synapomorphy}, a group which has nothing to do with the origin of birds; or they could be a plesiomorphic feature, but one which doesn't track the origin of birds [plesiomorphic for the dinosaurs, but it doesn't matter because birds aren't related to dinosaurs]. The collagen doesn't help one way or the other; its main purpose is to confirm the repeatibility of Schweitzer's earlier work on T by showing she finds the same stuff in another dinosaur from another time and place) J. Spencer (talk) 04:04, 16 June 2009 (UTC)

Sorry, the only thing you show me here is that you do not understand phylogenetics. Collagen is not a single character state that can be plesiomorphic or synapomorphyic, but a whole series, and for that reason, your scenario is rather unlikely. Furthermore, the analysis was unable to recover a monophyletic bird clade (<.7 posterior probablity in Bayesian analysis is effectively no support whatsoever), despite having the complete sequences of a neoaves and paleoaves specimen. And the Maximum likelihood analysis placed the dinosaurs in between neoaves and paleoaves, again without much support. What we have here is a well supported B+T clade, and poor support for anything else. -- Kim van der Linde ^{at venus} 12:24, 16 June 2009 (UTC)

BTW, if you deem this article insufficient, you should deem the original article even more insufficient, as the quality of the second paper is much higher. -- Kim van der Linde ^{at venus} 14:13, 16 June 2009 (UTC)

Oddly enough, we also have this: Molecular evidence for the hadrosaur B. canadensis as an outgroup to a clade containing the dinosaur T. rex and birds, by Shi Huang (posted May 2009, after Schweitzer et al.) (free pdf, Nature Precedings). My thoughts? We only have a small portion of the collagen sequence, from only two taxa. Perhaps it would be best to wait until we get more protein from more taxa before we start to draw conclusions from the phylogenies (beyond "T and B both show up together, so it's unlikely the original findings were incorrect")? J. Spencer (talk) 01:26, 17 June 2009 (UTC)

Well, first of all, that article is not peer reviewed, so it fails WP:RS. And it shows. First he lets disappear four of the eight sequences. Then he limits the comparison to the chicken, and concludes that because of the higher similarity of the chicken with T. rex, than with the hadrosaur, that the hadrosaur should be the out group. Unfortunately, the sequence of the ostrich is even more different, so on that basis, the ostrich should be placed basal to the dinosaur-bird clade. Add now 7 additional sequences, and it should be pretty obvious that thois article does not do a good job in what it pretends to do. Not strange for a article that is not peer-reviewed and is based on a single sequence. So, when are you going to reinsert the sourced statement you removed? -- Kim van der Linde ^{at venus} 05:28, 17 June 2009 (UTC)

I already said that I am not willing to go farther with this line of evidence until we have more taxa and protein. Particularly lacking are Cretaceous and Tertiary birds, and maniraptoran dinosaurs. You can put it back in if you want to, but I think it's jumping the gun. J. Spencer (talk) 13:11, 17 June 2009 (UTC)

Policy is not that all sources should be peer-reviewed, so it does in fact not fail WP:RS. Furthermore, making any inferences from the other article about bird origins is, given its scope, OR. Should we, however, try to do so anyway, surely we could — within your interpretation — only conclude from its outcome that, much to our surprise, a hadrosaur is a theropod? Birds after all by definition are theropods. Also I am at loss understanding how the topology, while not conforming to any phylogeny defended by anyone in recent times, could still be said to be seriously favouring one over the other. A polyphyletic "Neornithes" does not imply that Aves is not within Theropoda, it implies that the results have nothing useful to contribute regarding bird phylogeny.--MWAK (talk) 13:25, 19 June 2009 (UTC)

And if any valid conclusion can be drawn from such utter lack of scholarship as displayed in "Cladistics and the origin of birds: a review and two new analyses" it should be that if disregarding every rule of proper scientific method can still not produce a clear alternative to the theropod origin of birds, the latter hypothesis must be very well corroborated indeed.--MWAK (talk) 07:08, 16 June 2009 (UTC)

Whow, so explain to me, how can it be that this paper was published at all? And would you mind explaining where they went wrong on the scientific method? -- Kim van der Linde ^{at venus} 12:24, 16 June 2009 (UTC)

There are two different issues at stake here. The first, and most important to us, is the weight to be given to this article. Certainly it can have its proper place in the section about the BAND. However, it should not be presented in the lead section as adding to a presumed growing body of evidence that the consensus hypothesis would be incorrect. There is no such body of evidence. There is a sequence of attempts by the BAND to falsify the standard hypothesis (very commendable) which have failed and thereby corroborated this hypothesis. At any moment within this on-going process the latest attempts have not yet had the time to be refuted. This creates the illusion that there would be some new breakthrough, which by virtue of being the "latest results" would warrant some special mention. But only if, mirabile dictu, after discussion within the scientific community it had to be acknowledged as constituting a successful attempt at (relative) falsification, it is time to grant it a more prominent place. As of now, it is too early yet. And this brings us to the second issue.

Given the fact that the paper under consideration is so new, I feel hesitant to provide the in-depth analysis needed to justify my rhetoric above. Others are infinitely better qualified for this task than I am and I fear, in chastising fools, to make an even greater fool of myself, should I err on some technical point :o). However, should this display of modesty on my part not be deemed wholly convincing, I am willing to raise some points of concern which might suggest to any unbiased observer that all is not well in BAND-land:

1. It will have escaped no-one that the core project of the article is the removal from the analysis of nearly any and every synapomorphy the homology of which has ever been disputed by any BANDit. This is called a "conservative approach", presumably founded on a desire to use only those features we can be very sure of. Such an extreme limitation of data however, makes a caricature of the BAND-position itself. It is in this way basically treated as a body of unchanging propositions that can never be improved upon and that is immune to refutation. This is all the more problematic as this position has in fact changed considerably in the late nineties when the Maniraptora, previously by them considered a group of animals being completely different from birds, suddenly became birds themselves — and this for the sole reason they had been proven to possess feathers. What implications were there for the analysis of the other features? The authors consistently limit themselves to vague statements, e.g.: Confusion remains about the identities of the proximal carpal elements in Oviraptorosauria, Dromaeosauridae, and Troodontidae.
2. To the contrary other features, equally disputed between the camps but favoured by the BAND, are almost all included, despite the claim We were, however, as critical with respect to these characters as we were with respect to those in the CNM matrix. The authors seem at times to understand here the importance of the MANIAC-shift, e.g.: In recent years, the sharp dichotomy between the avian-crocodyliform dental morphology and mode of implantation on the one hand, and theropod dental morphology and mode of implantation on the other, has clearly become untenable. How true. Yet they conclude: Nonetheless, these characters are potentially phylogenetically informative in discriminating among competing hypotheses about the origin of birds and, therefore, were included in our analysis. Why was for these cases the "conservative approach" abandoned? Would it not have been more honest to simply announce "Suppose our side is right in all its assessments of anatomy: what cladistic analysis would that result in?"?
3. The authors included other archosauriform taxa in order to establish the position of birds within the "archosaurian" tree. Why were ornithischians and sauropodomorphs not among them? Or had they been included and did their presence cause a result that could not please the authors?
4. Crocodylomorphs were included. Why were these exact crurotarsan taxa chosen? They seem to include a lot of elegant forms — to catch a bird, no doubt — but lack many heavier groups. Or had these been included and did their presence cause a result that could not please the authors?
5. The matrix used as a basis was originally optimised to analyse advanced theropods. Does adding a few characters in order to enormously enlarge its scope not cause a fundamental imbalance? Were Archosauriformes and Crocodylomorpha not severely under-analysed? It seems at least a plausible partial explanation of the bizarre outcome of the analysis.
6. If we put the crocodylomorph hypothesis aside, of which the authors rightly assert that it has not received much attention in the literature (now why would that be?) and which they, understandably, dare not endorse any further, the only serious possibility different from the standard hypothesis would be a position of Aves within basal archosauriforms. Now the only basal archosauriform the authors manage to associate birds with is Longisquama. This however, is the worst of candidates. To begin with, its very status as an archosauriform is disputed, so that if the authors would not make themselves guilty of the same dogmatism they accuse mainstream paleontology of, they should have provided a full diapsid analysis. Then there is the inconvenient fact that it is only half a fossil. Worse, its conservation is so poor that most of its features are indiscernible. Of course this doesn't stop Mr Pourtless and Mr Martin from discerning them anyway. Sadly, the past record of these two gentlemen does not seem to justify the assumption of superior observational powers, needed to make their all too convenient conclusions valid. Certainly the "conservative approach" was not applied in this case, as characters are now scored based on unpublished material.
7. All that being said, we cannot deny a certain curiosity as to the final results. Suppose the BAND were right in all anatomical questions, how would an analysis look like? Who is in their interpretation the direct relative of birds? We'd really like to know. Strangely, the authors won't tell us. Apparently it is a sensitive secret we cannot be entrusted with. Instead of providing a strict consensus tree using the same method Clark employed for the original analysis, which might allow for the fairest comparison, the BAND, though until now not having cared for cladistics one way or the other, suddenly is moved by a concern for rigorous application of cladistic methods. Devotedly raising their eyes to the towering figure of the great Felsenstein, they use majority-rule trees and bootstrapping to ensure the collapse of the tree into a giant polytomy, which is then pruned to create the illusion that they are interested in its resolution. What horrid suspicions this awakens in the mind of an honest man! Could it be that the authors at first did attain a resolved cladogram — and that it still showed birds to be dinosaurs? Conversely, are we to believe that if such cladogram would have shown Longisquama or Sphenosuchus to be the avian sister taxon, it would not have been published by them?--MWAK (talk) 10:17, 22 June 2009 (UTC)

I respond in more detail later, but a quick question, where is the section about alternative theories? I check the headers, but there is nothing obvious! So, why do you think in that case that it ends up in the lead where there is at least SOME mention of alternative ideas? -- Kim van der Linde ^{at venus} 22:45, 22 June 2009 (UTC)

Would it be appropriate to mention and explain the acronym BAND somewhere in the main article? Perhaps even have a redirect from BAND? TomS TDotO (talk) 12:15, 22 June 2009 (UTC)

I agree that the attention given to the BAND is minimal. There is an alinea in "Modern research and feathered dinosaurs in China". On the one hand this is defensible, given the undue weight policy; on the other hand, to my personal taste, to meet NPOV-demands a bit more should be said, especially because the purely scientific point of view can be complemented by cultural considerations: there is no doubt the impact of the BAND on the public awareness of this subject is disproportional to its scientific importance — and precisely for this reason it should get a fuller treatment :o). And, of course, the different acronyms can then be explained too!--MWAK (talk) 05:31, 23 June 2009 (UTC)

Unreliable source for claim about number of anatomical similarities

The section on Origin of Birds#Features linking birds and dinosaurs starts with:

Over a hundred distinct anatomical features are shared by birds and theropod dinosaurs.

and gives one non-reliable citation to back it up: Chatterjee, Immoor (9 September 2005). "The Dinosaurs of the Jurassic Park Movies". Geolor.com. http://www.geolor.com/Jurassic_Park_Movies-Fact_versus_Fiction.htm. This source spectacularly fails WP:RS, it is not peer reviewed, the claim in the article is unsourced itself. Are there other sources that actually back up this claim? -- Kim van der Linde ^{at venus} 15:21, 17 June 2009 (UTC)

It is a poor source — though being peer-reviewed or referring to a source itself is not essential. Paul in Dinosaurs of the Air gives on page 185 an accumulated total of 305 potential synapomorphies with birds for all non-avian theropod nodes, 347 for all non-avian dinosauromorph nodes. Of course these were directly taken from description; not all of them will be the outcome of any single topology :o).--MWAK (talk) 04:56, 9 July 2009 (UTC)

Merge origin of avian flight into this

Anyonen agree or disagree? FunkMonk (talk) 00:32, 29 June 2009 (UTC)

Well, the origin of avian flight article is of a very poor quality, but because both it and the Origin of birds article are capable (and in need of) a very considerable expansion and the two subjects, though obviously related, are conceptually separate it seems best to keep both — otherwise we would probable be forced to split them at a later time anyway, so it would all be a waste of effort.--MWAK (talk) 04:39, 29 June 2009 (UTC)

If anything I'd say make Origin of avian flight the main article for this topic, as the topic is likely to expand. For example I'm confident that more needs to be said about the origin of feathers. --Philcha (talk) 19:15, 30 June 2009 (UTC)

There is also Bird flight. Shyamal (talk) 03:44, 1 July 2009 (UTC)

Indeed, and all three are valid articles. Obviously the phylogenetic issues are far larger than the subject of flight alone.--MWAK (talk) 07:42, 1 July 2009 (UTC)

Tetrapteryx

Shouldn't there be a section devoted to the "tetraptetyx" hypothesis? Now it is barely mentioned, but with the discovery of four winged specimens of Microraptor and Anchiornis it seems the hypothesis has been confirmed. FunkMonk (talk) 01:17, 25 September 2009 (UTC)

Well, the limited mobility of the femur, making it impossible to splay the hindlimbs, is a problem that hasn't been solved yet. Therefore the hypothesis is not taken too seriously at present — and the article reflects this. But a bit more attention to it wouldn't be amiss, I think.--MWAK (talk) 05:00, 25 September 2009 (UTC)

Dinosaurs = birds

Hi. Im a creationist, and ive stumbled across youur page. Has it not been proven that you could create a dinosar by "turning on" certain genes in birds using protiens? if this is true, then the DNA of birds and dinosaurs are the same. This leads to a point that dinosaurs were always what we, today, consider birds. The point that larger theropods were not found with feather nubs is logicly useless, due to the fact that a bird of that size would not need feathers to warm itself due to its size retaing body heat. please reply. —Preceding unsigned comment added by 98.117.104.208 (talk) 17:49, 29 March 2010 (UTC)

Well, you can't equate dinosaurs with birds or the other way around. Birds are a subset of dinosaurs. Therefore bird DNA is dinosaur DNA. By changing or activating that DNA you can create a bird that looks a bit more like other, now extinct, dinosaurs that were its ancestors, e.g. by having teeth or a longer bony tail.--MWAK (talk) 18:34, 29 March 2010 (UTC)

Of corse dinosaur and bird DNA is not the same, its the same way that two bird species DNA are not the same but have different levels of commonality in specific sequences. Enlil Ninlil (talk) 03:33, 5 October 2012 (UTC)

Dino Birds

Now that most people agree that birds are a type of theropod dinosaur, does that mean that birds are now considered to be in the reptile class? — Preceding unsigned comment added by 72.89.208.10 (talk) 00:24, 30 May 2011 (UTC)

That's a tricky question. Concepts like "class" are used in the old Linnaean Taxonomy. In that system it was allowed to use so-called paraphyletic groups, i.e. groups that do not contain all descendants, e.g. if such descendants are too different in build. So most people talking about "class" would say: "Birds are a Class of their own, Aves, and thus not part of the Class Reptilia". In this view it wouldn't matter whether it were determined that birds are derived from some particular group of reptiles. After all, its has been understood since the early 19th century that birds are closest in affinity to reptiles.

Linnaean Taxonomy makes some sense if you are studying modern animals. Birds are clearly very different from their closest living relatives the Crocodylia. However, for palaeontologists, who are studying the evolutionary tree of life as it develops through time, it is more harmful than useful. Because evolutionary change is always very gradual, there is no reason to exclude any descendant from the group. Modern palaeontologists therefore use only groups containing all descendants, called clades. Reptilia can be defined as such a clade and will then also contain the birds. The first who did this, I believe, was Gunnar Säve-Söderbergh in 1934 (and Jacques Gauthier did it again in 1984 :o). Of course there might be some confusion between Reptilia as a clade and as a Class. Some people therefore prefer to use the name Sauropsida for the clade. And to confuse matters even more, some people who use Sauropsida also use a smaller clade Reptilia. In principle you can add to the confusion by using a clade concept and still call it a Class. Luckily most palaeontologists are now abandoning the old ranks, as they are scientifically meaningless anyway: it is logically impossible to determine by scientific research whether a group is e.g. a Class or not. It's a matter of choice, not fact.

In short: birds are part of the clade Reptilia. They are not part of the Class Reptilia unless by "Class Reptilia" you really mean "clade Reptilia". For natural science it doesn't matter whether they are part of the Class Reptilia, because that is an unscientific concept.

I hope this helps a bit ;o).--MWAK (talk) 05:57, 30 May 2011 (UTC)

Owen not a creationist

Richard Owen was not a creationist, though he opposed Darwin's mechanism for evolution. He believed in self-organizational (aka "creative") properties of biological matter, but this places him in the company of some modern developmental biologists.CHW100 (talk) 00:19, 2 August 2011 (UTC)

Contentious ?

The first sentence says that the Origin of birds is a contentious topic. This is contradicted by the first reference:

"A wealth of recently discovered fossils has finally settled the century-old controversy about the origin of birds and it has made the evolutionary saga toward modern birds one of the best documented transitions in the history of life. This paper reviews the evidence in support of the origin of birds from meat-eating dinosaurs"

--Ettrig (talk) 16:49, 6 February 2012 (UTC)

There are people who would disagree with that reference — and therefore the topic is still contentious. Also we have to consider it from a more historical point of view.--MWAK (talk) 20:02, 6 February 2012 (UTC)

There are going to be people who disagree with any statement, including ones like "the Earth orbits the sun" or "continental drift occurs". I'd say it's been historically contentious, but there is now a scientific consensus disputed by a handful of fringe researchers. It's no more contentious than say, evolution itself. MMartyniuk (talk) 14:17, 7 February 2012 (UTC)

This article says the idea that birds are derived dinosaurs, first championed by Huxley and later by Nopcsa and Ostrom, enjoys near-unanimous support among today's paleontologists.[14]. That's two citations against contentiousness. I see no citations for. --Ettrig (talk) 11:07, 7 February 2012 (UTC)

I presume you know of the existence of the BAND. I agree that the impression should be avoided that there would be no clear majority position that birds are dinosaurs. In itself it would be better if the first sentence read "has been an contentious topic". However, the present tense is preferable because it serves the definitional function of the first sentence better. Furthermore, this very issue shows how even a subject on which scientific consensus exists, can be quite contentious. The BAND are a small minority but are very vociferous, create an enormous publicity and manage to convince editors that their articles should be published in the peer-reviewed literature, including Nature. See?--MWAK (talk) 13:37, 7 February 2012 (UTC)

found NE recognized

Anyone knows what this statement in the article means? : clavicles had been found in theropod dinosaurs before Heilman wrote his book, but had gone unrecognized --Ettrig (talk) 16:33, 8 February 2012 (UTC)

Well, they weren't recognised as such. A famous example is the holotype of Oviraptor, seen here:

where the furcula is clearly depicted on the right metacarpus but wrongly identified as the interclaviculare. In all fairness it should be said that the book really was written by Heilmann before 1916; the English edition appeared in 1926. So he couldn't have known of Oviraptor anyway. But there are much earlier occurrences. The oldest found non-avian theropod furcula must be that of the Bavarian specimen of Compsognathus discovered in 1859 or earlier. It was only recognised by Peyer in 2006!--MWAK (talk) 20:17, 8 February 2012 (UTC)

Birds ain't come from no dinosaurs

If birds are really derived theropod dinosaurs, then why does the embryological evidence for which digits birds have contradict the fossil evidence for which digits extinct theropods had? — Preceding unsigned comment added by 156.26.238.180 (talk) 22:29, 4 October 2012 (UTC)

Please provide evidence for your claim, or it is just heresay. Enlil Ninlil (talk) 03:14, 5 October 2012 (UTC)

This issue is dealt with in the "Digit homology" subchapter. In general it should be pointed out that many, more basal, theropods have been found that have the same finger phalanx structure as basal birds. Should the embryological evidence be seen as proving that digit II, III and IV are present in the avian hand, the same evidence would indicate that these digits are also present in the more basal theropod hand. So, at best the digit homology argument shows some split, either in morphology or in phylogeny, within Theropoda, not that birds aren't theropods.--MWAK (talk) 07:01, 5 October 2012 (UTC)

Discussion on title of taxon evolution pages

Hi, There is a thread here you may be interested in, about a consistent naming for articles dealing with evolution of taxa. Thanks! --Cyclopia^talk 17:12, 26 November 2012 (UTC)

Is the acronym BAND difficult to source?

My introduction of a reference to the acronym BAND was deleted because it is very informal and difficult to source. I cannot argue whether it is very informal (too informal to be worthy of mention), but is it difficult to source? If it is, is that not good reason to do the work to find a source for it, to help the person who is curious about the acronym? TomS TDotO (talk) 11:12, 10 August 2013 (UTC)

BAND is really a nom de guerre. Perhaps in a few generations time, it will have become a normal description for this phenomenon, in the history of science. It is not so now and it might confuse the reader if it were mentioned in the lead — unless entire chapters were dedicated to it, justifying a fundamental change in the lead structure. Given the level of sourcing apparently required for the main text (peer-reviewed review papers of peer-reviewed papers :o), the easily accessible sources, in blogs and internet fora, will probably not suffice. Perhaps we could mention it in a footnote.--MWAK (talk) 12:56, 10 August 2013 (UTC)

I have no problem with a less formal source just to source the name BAND, since it's unlikely to be a controversial fact. I wouldn't want to use a blog or forum, of course, but this should be fine. (I wouldn't consider it sufficient to put the acronym in the lead, but perhaps lower down in the article.) Note that the source implies that the BAND no longer exists, though ("at conferences in the 1980s, 1990s, and 2000s"). Arc de Ciel (talk) 08:17, 13 August 2013 (UTC)

Current disputes on origins

How prominent are the researchers who believe birds are not a group of dinosaurs? It seems to me that this falls under WP:FRINGE and as such should not be mentioned in the lead, except to the extent that the historical controversy is relevant. (Of course, if their position is sufficiently prominent to be given weight in this article, this needs to be shown using secondary sources, i.e. academic reviews). Arc de Ciel (talk) 08:15, 3 August 2013 (UTC)

Well, the point is that these researchers have generated considerable media attention. This means that if we say "Yeah, well, that attention is wholly out of proportion to their true scientific merit", we had better imply that immediately, by pointing out in the lead that they are a small minority. In other words: due to the likes of the late Martin and A. Feduccia this has become a partly pseudo-scientific subject. A sad thing (or a lot of fun) but true nevertheless. Mainstream scientists have not been able to simply ignore the BANDits and so scientific articles and books have been forced to refute their arguments, to the extent that a thorough Feduccia-bashing has become a traditional feature of any self-respecting scientific exposé of the topic. We merely reflect this. If it is any consolation you may see it as the final stage of the historical controversy ;o).--MWAK (talk) 13:32, 3 August 2013 (UTC)

If the media attention is out of proportion to the scientific merit, that means that per WP:UNDUE we need to exercise extra caution that this article does not give it more attention than the scientific merit deserves. :-) Can you please identify the academic secondary sources which discuss these positions seriously, even if it is followed by refutation? Preferably the sources would be recent, say within the last ~5 years, in order to indicate that the issue is still relevant. Thanks, Arc de Ciel (talk) 02:20, 4 August 2013 (UTC)

No, because the (content of the) media attention is in itself a notable phenomenon! As a result the subject of the Origin of Birds is not strictly scientific. Perhaps the consequences of this become clearer when considering subjects where the pseudo-scientific content is more dominant. When treating e.g. the topic of the Loch Ness Monster we should not say "The hypothesis that such a monster exists, is utterly discredited, therefore we are not allowed to mention this hypothesis as doing so would give it undue weight". Why would this be absurd? Because the way such concepts socially operate, the pseudo-science is an inherent part of it. But is is the same with the Origin of Birds. The very reason most readers consult the article in the first place, is likely that they have read about the "controversy" in some popular science article or book. It would then be disingenuous for us to ignore this ("Birds might not be dinosaurs? Can't say I've ever heard of that, Sir. Now, if I may draw your attention to this cladogramme...") especially since the existence, content and length of the article have been mainly inspired by an ardent desire to refute the BAND position :o). Speaking of which: the last academic book on the subject of birds origins: Dyke, Gareth and Kaiser, Gary (eds.) (2011) Living dinosaurs: the evolutionary history of modern birds, Chichester, GB, Wiley, 440pp again felt it necessary to explicitly declare Feduccia c.s. obsolete. The very title says it all, no? I've yet to see a publication named Living synapsids: the evolutionary history of modern mammals :o).--MWAK (talk) 07:02, 4 August 2013 (UTC)

Then we should discuss it in the context of the media attention, if enough of it can be found, rather than in the context of the research. :-) I phrased my previous reply poorly - I wasn't intending to imply that there should be no mention at all (indeed I have no opinion yet either way; I've already made the edit I saw as most important). But it seems to me that the article (mainly the reference in the lead) implies that the claims have some scientific merit - thus my request for sources. In the book you cite, could you provide a page number? I don't have full access, but I'll be able to read it if it's provided in the Google Books preview. (If not, a couple of quotes would be great.)

As a further comment, I see only one paragraph on the BANDit claims in the article body. In an article of this size, I don't think that's enough to justify a mention in the lead. So if the material exists to support mention in the lead, the current discussion in the article doesn't seem to reflect that. (I also note that the sources describing the claims are primary.)

I will be away from Wikipedia for a short while (a few days to a week), but I will read your reply when I return. :-) Arc de Ciel (talk)

Yes, but it is more fundamental. Popular science shapes the perception of a certain subject. It thereby codetermines what that subject is. So, it's not simply a matter of providing popular science sources that call it a controversy: it's a matter of us being honest in acknowledging the obvious fact that the controversy dominates the present public perception. Now, I'm not quite sure what reference in the lead you are referring to (and what source would be "primary", i.e. unpublished information). If it's the part about the protein, all this can be easily solved by removing it in its entirety as the research it mentions, is not very important anyway! Indeed the lead does not summarise the main text very well — and that text is not a very good description of the BAND phenomenon. Nevertheless, as it reads now: "The origin of birds has historically been a contentious topic within evolutionary biology. However, only a few scientists still debate the dinosaurian origin of birds, suggesting descent from other types of archosaurian reptiles", it is acceptable. We could merely claim there is a consensus, but that's not strictly true and if we qualify this by stating that there "almost" is a consensus, we had better express ourselves less weasely and directly indicate the true state of affairs. I think it is perfectly alright to mention the BAND as the end phase of a gradual acceptance of the dinosaurian hypothesis. As Dyke e.a. (2011) states on page 3: "However, concerns about apparent differences between birds and dinosaurs arose in the early 20th century (Heilman, [sic] 1926) and generated a heated debate that lasted until the beginning of the 21st century". The main refutation of the BAND position is on pages 22-25 by Makovicky & Zanno.--MWAK (talk) 17:52, 4 August 2013 (UTC)

I use "primary" in the Wikipedia sense; see WP:PSTS. Most articles published in academic journals are primary sources. I was referring to the discussion in the body, specifically sources 47-49, currently used to support the text "A small minority...forelimbs." Since they are primary sources, their statements must defer to statements in secondary and tertiary sources, which are stronger and determine the degree to which specific topics should be described (including the degree to which they should be mentioned in the lead).

Thank you for the page numbers - this makes things a bit more interesting. :-) Since this source is non-primary, I would not be opposed to using these few pages as a source for a paragraph in the article body, perhaps at the end of the "Research history" section. Such a paragraph, probably with other sources as well, could then be used to support mention in the lead. I note that having read the pages (or rather pages 23-25 as my preview skips 22), it seems to support my point that there doesn't appear to be any scientific validity (which you haven't commented on directly). Among other things, I see descriptions of selective sampling, statistical errors, etc.

I have no problem with considering the BAND to be the "end phase of a gradual acceptance" (within reason - there are a few scientists outside the consensus on every topic), but of course my concern is the relative importance of this phase to the article. AFAICT the sources consider the debate over, e.g. the quote you cite from Dyke et al ("until the beginning of the 21st century"). But I'm not sure it's an "obvious fact" that the controversy dominates the public perception. (Certainly I had never heard of it before, except among young-earth creationists. If their viewpoint alone is considered to have sufficient weight, then the viewpoint should be attributed to them.) In terms of a secondary popular source, I think that if there is an editorial/news item or two in Science or Nature that discusses the issue in detail, that would probably be a good argument for inclusion of the current statement in the lead ("However...reptiles") based on popular recognition.

Thanks for your patience in waiting for my replies (*disappears for another week or two*). Arc de Ciel (talk) 07:15, 9 August 2013 (UTC)

I fear you have misread WP:PSTS: articles in journals, academic or otherwise, are secondary sources if not directly and merely describing historical events (and no, a fossil, an experiment, an hypothesis are not historical events in this sense :o). So you don't need higher-order review papers to decide whether regular scientific articles are valid content of a Wikipedia lemma (although it might be advisable to be guided by them). I would say that almost certainly the controversy dominates the public perception about the origin of birds, for the simple reason that without it there would not be much of a public perception of the subject in the first place. And surely you must remember having read, in popular science books or articles, phrases like "Today, many scientists think that birds are descended from dinosaurs"? Have you ever read "Today, many scientists think that bats are descended from mammals"?

As regards Nature or Science editorials: there have in these magazines been explicit reviews of Feduccia's 2011 book Riddle of the Feathered Dragons. In Nature by Chiappe and Norell; in Science by Campbell (who mainly complained about the illustrations, in my view about the only redeeming aspect of the book. Nice lay-out too). And was this work, that can be charitably described as the ravings (or rant) of a madman, self-published, the poor Feduccia going from door to door to hawk his ware to the unneedy? No, it was brought out by the press of one of the world's most prestigious universities: Yale! The BAND is not completely marginalised as yet...By the way, the full Makovicky & Zanno chapter can be found here: http://www4.ncsu.edu/~mhschwei/Research_files/Makovicky___Zanno_2011_theropod_diversity_and_avian_characteristics-1.pdf --MWAK (talk) 14:38, 9 August 2013 (UTC)

I see that the entire fringe theory crowd is using a definition of primary source that is at odds with the policy. If an adherent of a fringe theory has published an article containing his opinions, said article is not a primary source by virtue of him being an adherent of a fringe theory. The closeness to and involvement with an event that WP:PSTS refers to must be seen as temporal, spatial and causal criteria. If I twitter "I [causal closeness] just [temporal closeness] threw a stone through my neighbour's [spatial closeness] window glasses", the twitter message is a primary source. If I then defend my action in a letter to a local newspaper claiming: "I had to do it. My neighbour is an extraterrestrial alien. We all have a right to stand our ground against creepy neighbour aliens", this letter is a secondary source as regards the "neighbour alien hypothesis" and the legal "justified defence against neighbour aliens" doctrine. The usefulness of that source is limited by its reliability (it is e.g. not a reliable source that neighbour aliens exist) and its notability (it is not notable unless it will e.g. ultimately induce the State of Florida to adopt the ET Act, allowing neighbourhoods to preventively eliminate suspected neighbour aliens, if it hasn't been shown they can't fly by throwing them off a sky-scraper). But not by it not being a secondary source.--MWAK (talk) 08:00, 10 August 2013 (UTC)

WP:PSTS: "similarly, a scientific paper documenting a new experiment conducted by the author is a primary source on the outcome of that experiment." There is a more thorough description at WP:MEDRS; it isn't directly applicable as MEDRS is explicitly designed for medical content, but the idea is the same. If you wish, I would be more than happy for us to request clarification at a relevant location.

I like your "neighbour alien" example. :-) However (again quoting PSTS): "A book by a military historian about the Second World War might be a secondary source about the war, but if it includes details of the author's own war experiences, it would be a primary source about those experiences." You're more experienced on Wikipedia than I am, but it seems to me that if the author's article details their own experiences, then it remains a primary source (with respect to those experiences). I don't intend to say that whether a source is primary depends on whether someone supports a fringe theory (and I don't think I've ever seen anyone argue this). My reasoning here applies to all sources. :-) That said, a fringe statement may require greater sourcing strength than non-controversial statements, due to WP:EXTRAORDINARY.

Thanks for the link to the full chapter; I will read through the rest. Could you please also link the book reviews you mention? Google searches on feduccia feathered dragons site:nature.com and feduccia feathered dragons site:sciencemag.org don't turn up anything. Arc de Ciel (talk) 08:17, 13 August 2013 (UTC)

Darn, I fear I have to eat some crow here. Indeed, descriptions of experiments are explicitly mentioned as constituting primary sources. That is unwise and incoherent, but it is so nevertheless. Another corvid will have to be consumed in admitting that I got the reviews all wrong, foolishly letting me be misguided by, well, a review on Amazon. The Chiappe review was not in Nature but in BioScience and the Campbell review was not in Science, but The Auk, and worse, it was not by Campbell but by Geist. Obviously BioScience, let alone The Auk, do not count as popular science magazines. We have of course somewhat older occurrences: e.g. Hinchliffe, R. (1997), “The Forward March of the Bird-Dinosaurs Halted?,” Science, 278: 596-597, October 24 or Gee, H. (1998) "Birds and dinosaurs - the debate is over" Nature 2 July 1998. Ruben was attacked in: Tom Simonite, (2005), "Dinosaurs breathed like birds", Nature News doi:10.1038/news050711-8 (13 July 2005). The "digit problem" was tackled in: Matt Kaplan, (2009), "Dinosaur's digits show how birds got wings — A new dinosaur species looks set to solve an old evolutionary puzzle", Nature News doi:10.1038/news.2009.577 (17 June 2009). In 2009 Witmer referred to the "temporal paradox" in Lawrence M. Witmer, (2009), "Palaeontology: Feathered dinosaurs in a tangle", Nature 461: 601-602 (1 October 2009). The collagen hypothesis of the Sinosauropteryx integument was attacked in: Matt Kaplan, (2010), "Fossil feathers reveal dinosaurs' true colours — Pigment-storage sacs found in fossils give hints about hue", Nature News doi:10.1038/news.2010.39 (27 January 2010). You see the pattern: as the BAND attacks perceived weaknesses in the mainstream hypothesis, it gets mentioned whenever these problems are partly solved.--MWAK (talk) 16:57, 13 August 2013 (UTC)

No problem :-). Out of your new citations, I mainly looked over the three most recent - they seem to be about the solutions to open questions/puzzles in the field, not about the controversy, i.e. none of them seem to treat the existence of people arguing for birds not being dinosaurs as important. I think the best is the one that mentions the temporal paradox, but the description is limited to a single paragraph (part of which is refutation - or actually, not really refutation but a statement that the paradox was "never a serious challenge"). They seem like reasonable sources to use for the article, but not really to supply weight to the BAND.

If I might summarize my opinion thus far: I think that the BAND should clearly be mentioned in the article, mostly as historical but with some mention of people who support it today (adding, of course, that their views are now rejected, which the article already says). The current description of the BAND should be rewritten so that it relies on secondary sources; Dyke et al is a good one to use. I don't think the BAND has sufficient WP:WEIGHT to be mentioned in the lead, but the lead should contain a description (say, a paragraph) describing the historical controversy, which it currently doesn't have. What points do we disagree on? :-)

I am about to go on wikibreak, but perhaps when I return we can see if there are any changes we can make. Arc de Ciel (talk) 03:42, 19 August 2013 (UTC)

I think we're still stuck with the fundamental problem: even after the (indeed quite necessary) changes in the lead, this will still have to give the reader an impression about what the current status is. The present situation can be most accurately described by something on the lines of "Today, there is only a small number of scientists left who doubt that birds are dinosaurs". That is better than "There is a consensus that birds are dinosaurs" for that is simply not true, unless it is meant as "There is by definition a consensus among scientists who matter that birds are dinosaurs" which would violate the NPOV policy. Now, having established that the lead should state that "there is only a small number of scientists left", it would be a reductio ad absurdum of the undue weight policy to suddenly exclaim "But wait a minute! If there are so few of them left, they should not be mentioned at all. That would be undue weight!" We do not unduly impart weight by showing the little weight there is. Nor can it be cogently argued that, as the BAND should only be a small part of the main text, there should be no reference to it whatsoever in the lead. Yes, the lead is in principle an abstract of the main text, but that abstract should first of all reflect its logical structure, not simply the quantity of the content. The very reason why there should be little attention to the present activities of the BAND: that birds would not be dinosaurs is today an extreme minority view, forces us to mention that today it in fact is an extreme minority view in the lead.--MWAK (talk) 06:22, 19 August 2013 (UTC)

Proavis

Please, in the talk page of the article "Origin of avian flight"... read this, a thread I just started. Kintaro (talk) 20:37, 7 October 2013 (UTC)

The discussion continues here. Thank you. Kintaro (talk) 21:40, 9 October 2013 (UTC)

Thecodonts and Oregon State University research

http://www.dailymail.co.uk/sciencetech/article-1192019/Why-birds-NOT-descended-dinosaurs.html http://www.sciencedaily.com/releases/2010/02/100209183335.htm

Looks like scientific evidence has challenged the assumption that birds came from theropod dinosaurs. In fact some dinosaurs may have come from birds. But it appears that birds came from thecodonts. — Preceding unsigned comment added by 71.236.244.31 (talk) 21:54, 24 March 2014 (UTC)

Well, not really. The first study you refer to, simply claims that modern birds have a largely immobile thighbone that doesn't impede their breathing. But as the very first birds had demonstrably a different system, this has nothing to do with whether birds are dinosaurs. The second study claims that Microraptor lived in trees. Could well be. Does it follow from this that birds could not have descended from small ground-dwelling earlier theropods? No, to the contrary: because Microraptor is generally built like such a ground-dwelling theropod, it being arboreal nevertheless actually strengthens the case that birds are dinosaurs. Indeed, as birds are dinosaurs themselves, quite a few dinosaurs (in fact the overwhelming majority of known and predicted species) descended from birds. To claim that they came from "thecodonts" is literally meaningless as that concept is undefined. It's the same as saying "They belong to Group X — but I have no idea what Group X is". This reveals the fundamental point here: apart from dinosaurs, there is no serious evidence for any concrete alternative group birds could have belonged to. However, the assumption, or hypothesis, that birds are dinosaurs, is supported by an ever-growing mountain of data.--MWAK (talk) 07:39, 25 March 2014 (UTC)

Scansoriopteryx; shrinking lineage

It would be premature to include this paper in the article now, but we should keep our eye on it to see whether it gains enough traction to be worth devoting a section to: doi:10.1007/s10336-014-1098-9.

However, this one can probably be included immediately: doi:10.1126/science.1252243.

Well, the first article is more of a postmature nature. A lot of traction would be needed to move that dead horse :o). The second article is relevant, though not easy to fit in.--MWAK (talk) 07:49, 2 August 2014 (UTC)

Schweitzer et al. saying birds are not theropods?

To my knowledge, the study named says nothing of the sort, but that's what this line in the lead implies: "A second molecular study robustly supported the relationship of birds to dinosaurs, though it did not place birds within Theropoda, as expected. This study utilized eight additional collagen sequences extracted from a femur of Brachylophosaurus canadensis, a hadrosaur.[6]" Why is this? Gruekiller (talk) 23:42, 23 August 2014 (UTC)

Well, the results were even stranger: Brachylophosaurus and Tyrannosaurus grouped together, their clade was related to the ostrich and that clade again was the sister group of the chicken. Who would have thought? So the "robust support for a relationship" is bit deceptive as that relationship would place birds outside of dinosaurs. And they would be paraphyletic as well! Huxley vindicated. Luckily for the standard model, the reliability of the method used is very low as only a few protein sequences could be investigated and the assumption that their changes would be evolutionary neutral is only a working hypothesis. I think it was a mistake to mention this paper in the lead :o).--MWAK (talk) 06:49, 24 August 2014 (UTC)

not much meat there

The origin of birds refers to the initial stages in the evolution of birds.

This is almost exactly the sort of thing deprecated in WP:REDUNDANCY. —Tamfang (talk) 08:54, 22 March 2015 (UTC)

Origin of songbirds, parrots and pigeons

On the ABC Television scientific program, "Catalyst", broadcast on 10 March 2015, an interesting segment entitiled "Where Birdsong Began" was shown, in which it was stated that songbirds, parrots and pigeons all evolved in Australia.[1] Should this be mentioned on the Origin of birds page - and, if so, where in the article should the information be added? Thanks. Along with the printed transcript of the segment, the "Catalyst" webpage includes a video of the segment, so the segment can be viewed and heard. The segment includes a comment that the oldest known bird fossil has been found in Australia (over 53 million years old - predating other fossils of birds by at least 25 million years). Also, there is a comment that DNA was part of the research used. The research was made by scientists who were very surprised by their findings. Figaro (talk) 09:23, 22 March 2015 (UTC)

The specific interrelationships of the various modern bird groups are extraordinarily controversial and seem to change with each new study. the program you saw would have been more responsible if it noted this is one hypothesis among dozens. I'd leave out specifics like this without at least a few good literature sources to back it up. Dinoguy2 (talk) 13:28, 22 March 2015 (UTC)

Also, the subject of the article is the origin of birds in general, not so much of (even major) subgroups. And the 54 million years old fossil is the purported oldest known songbird.--MWAK (talk) 17:45, 22 March 2015 (UTC)