Guest Post: Epidexipteryx, The Vampire Peacock of Daohugou

As promised here is the guest post on the new feathered dinosaur by my colleague Corwin Sullivan

In recent years there’s been no shortage of feathered theropod fossils, avian and non-avian, from the People’s Republic of China. Almost all of them come from the Lower Cretaceous Yixian Formation of western Liaoning Province, historically a part of Manchuria. The exquisitely preserved Yixian fossils, which include everything from plants to insects to mammals in addition to the famous feathered wonders, give us an astonishingly clear window into an Early Cretaceous ecosystem.

However, it must be said that dinosaurs of a feather do not always flock entirely together. The profusion of specimens from the Yixian Formation has tended to overshadow the small number of highly intriguing feathered theropods that have been collected at another locality, Daohugou in eastern Inner Mongolia. The Daohugou beds are practically across the provincial border from the Yixian of western Liaoning, and are similar to the Yixian in many respects: both are lacustrine deposits that have yielded a mixture of plants, invertebrates, non-dinosaurian vertebrates such as salamanders and pterosaurs, and feathered dinosaurs. However, the Daohugou beds are substantially older, being Middle to Upper Jurassic rather than Lower Cretaceous.

For years the only two feather-sporting Daohugou taxa were Pedopenna, known only from a single partial leg, and an intriguing but also incompletely known creature called Epidendrosaurus. (Scansoriopteryx, a putative third, is quite probably a synonym of Epidendrosaurus.) Epidendrosaurus was a kind of dinosaurian aye-aye, a small, possibly arboreal maniraptoran with an elongated third manual digit. It is apparently close to the origin of birds, emerging just basal to Archaeopteryx in phylogenetic analyses. This is particularly satisfying because the Daohugou fossils also slightly precede Archaeopteryx in age, being at least a few million years older than the Solnhofen beds.

The feathered maniraptoran Epidexipteryx hui. Image from Zhang et al., 2008.

The feathered maniraptoran Epidexipteryx hui. Image from Zhang et al., 2008.

Now Epidendrosaurus has a close cousin from the same locality, as Professor Zhang Fucheng of the IVPP and a few coauthors – including, clinging barnacle-like to the end of the authorship list, yours truly – report in a Nature paper that came out earlier today. (The citation is given below, and the paper is here, but full access requires a personal or institutional subscription.) The new animal, Epidexipteryx hui, is apparently not a second aye-aye but rather something more like an undersized vampire peacock. I should hasten to nip misinterpretations in the bud by insisting that I am not promoting any wild hypothesis of blood-drinking, or even necessarily carnivory. But it does have big, protruding teeth at the front of the mouth.

Epidexipteryx also has what we call in the paper elongate tail feathers (ETFs), making the tail into a showy frond that is in remarkably good shape after more than 150 million years. What is particularly exciting about this, for those of us interested in the evolution of feathers, is that the rest of the body of Epidexipteryx seems to have been covered only by short, rather fuzzy protofeathers of a kind that are now familiar from several maniraptorans more or less remote from the origin of birds. Protofeathers of this kind might well have provided insulation, and perhaps a bit of either camouflage or visual flair depending on their colouration. But they weren’t going to get Epidexipteryx into the air, so the taxon was evidently neither a flier nor a glider.

The ETFs on the tail, however, are downright ostentatious. They come in two pairs, and are of prodigious length in proportion to the animal’s skeleton. In life they would have been prominent, conspicuous, and probably a bit physically awkward to drag around, suggesting that they functioned purely as a visual signal. The mind leaps instantly to sexual selection, and torrid scenes of colourful tails swaying back and forth before the beady eyes of mesmerised females, but of course there are other possibilities. For example, the ETFs could have been a battle flag brandished at territorial rivals, rather than a gaudy ornament wielded to impress potential lovers. The sexual explanation is far from improbable, but at present we cannot even determine whether the holotype and only specimen of Epidexipteryx was male or female. Taking cues from extant birds, it is somewhat more likely that any sexual signals were sent primarily by males.

Epidexipteryx and Epidendrosaurus seem to be sister taxa, forming a clade called Scansoriopterygidae that lies immediately basal to Archaeopteryx. This might just indicate that display feathers preceded the evolution of flight feathers in avian evolution, a conclusion that would have implications well beyond the scope of this blog post. However, there’s no question that the pattern of early feather evolution was exceedingly complex. The dromaeosaur Microraptor, after all, was almost certainly capable of getting airborne even if palaeontologists disagree about its exact flight (or gliding) posture and capabilities. Did Microraptor evolve its aerial abilities independently of Archaeopteryx and other birds? Or was access to the air part of the common inheritance of avialans and dromaeosaurs, a possibility that would imply secondary losses in some members of each group? Is it even possible that avialans might turn out to roost phylogenetically within dromaeosaurs, so that volancy could be primitive for the former and a subset of the latter? At the moment the first alternative strikes me as most intuitively plausible, but the evidence is not yet conclusive. Nevertheless, we now have Epidexipteryx, the vampire peacock of Daohugou – and a basal avialan in the hand, as they say (well, they don’t really, but they should), is worth two in the outcrop.

Zhang, F., Zhou, Z., Xu, X., Wang, X. and Sullivan, C. 2008. A bizarre Jurassic maniraptoran from China with elongate ribbon-like feathers. Nature 455: 1105-1108.

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35 Responses to “Guest Post: Epidexipteryx, The Vampire Peacock of Daohugou”


  1. 1 Jaime A. Headden 24/10/2008 at 12:49 pm

    My comment arises from the photos. The proximal caudals are shown disassociated from the sacrum and scattered behind the animal, while the distal caudals are in a tightly connected series just dorsal to them. How seriously did you or your co-authors consider the possibility of the caudal sequence being disarticulated, especially given the condition in Scansoriopteryx (or, if a synonym) Epidendrosaurus?

  2. 2 Corwin Sullivan 24/10/2008 at 2:01 pm

    Thanks for the comment. It may not be apparent in the small image posted here, but the proximal caudals are not exactly scattered – they’re more or less naturally articulated posterior to the sacrum, although there is of course a break between the proximal and distal caudals. The break does prevent us from being sure of the exact length of the tail, but I find it hard to imagine that a large number of caudal segments are missing. The distal section of the tail is just too close to its proper alignment with the proximal section. Still, it would be nice to have a specimen with a fully articulated tail, in order to confirm this judgement.

  3. 3 SteveF 24/10/2008 at 5:17 pm

    Thanks for the post. I have a probably slightly dumb question – when looking at these kind of protofeathers, how seriously do you take the argument about them possibly being degraded collagen as suggested by Lingham-Solair and others?

    I remember reading their 2007 paper and thinking it were a bit odd – if the protofeathers were collagen, then surely other non-dino things in the Liaoning beds should have pseudo feathers. However, I’m not an expert on this kind of thing, so I was just wondering from an outsiders perspective, if this kind of argument is taken seriously and whether you and your co-authors considered it.

    Thanks.

    PS; the relevant paper in case there is anyone reading not familiar with the degraded collagen argument:

    http://publishing.royalsociety.org/media/proceedings_b/RSPB20070352.pdf

  4. 4 David Hone 24/10/2008 at 6:11 pm

    Speaking personally, not very seriously at all. It is a good point and worth making to amke sure people do check, but when you look at them in detail they are clealry very different (collagen and feathers). It’s also hard to argue that something like Epidexipteryx’s tail feathers are collagen – why would they be out there separated from the tail? And their edges don’t seem to have degraded at all I notice. This is also true of a bunch of other feathered taxa (and I am luck enough to have seen a lot of material here in China as well the fascinating and muich ignored from this p.o.v. Juraventor) where one can see individual tufts of feathers of plumes, in structures unlike anything that has been shown oreven hypothesised for degrading collagen. Just look at something like Caudipteryx and it is clear that this simply cannot be collagen (or for that matter anything else like it) degrading on the animal.

  5. 5 Jaime A. Headden 24/10/2008 at 6:43 pm

    David,

    It is Martin and Lingham-Soliar’s contention that only the filamentous integument is degraded collagen from frills, while they aver that Caudipteryx and the like are all truly feathered, non-dinosaurian birds. Thus they have cleansed themselves of the possibility that the fibres they cannot reason as being feather stage-1 analogues. Epidexipteryx looks to have a condition similer to Sinosauropteryx, with filaments branching from a common base, but the tail thingies lack what appear to be barbs at all, so its possible, as they cannot fit into the current model for development of feathers (known from organic studies), that the tail thingies are nothing like feathers. I am not saying they aren’t, of course.

    Corwin,

    I understand the uniqueness of the specimen, but given the gross overall similarity of the material to Scansoriopteryx, how implausible is it to asusme that it is in fact the same taxon? If this were so, then the case for a longer tail becomes the de facto basic premise, merely because the distal tail is instact yet separated, and the proximal caudals are, while close to the sacrum, lose and moved downward and away from the rest of the tail. The fact that the tail is broken in this fashion leads to speculation of the nature of the tail and how long it could be. One cannot easily conjecture the actual length unless one assumes the tail was broken downward, then pulled up and over forward to the point of breakage. If the tail was dislocated due to scavenging, it is ever more plausible to assume there may be a missing segment. Scansoripteryx and potentially Epidendrosaurus (the type specimens, at any rate) show long tails; is this then not the baseline?

  6. 6 SteveF 24/10/2008 at 7:32 pm

    David,

    Again from a laymens perspective I find it hard to interpret these features on Microraptor as anything other than feathers:

    Jaime,

    So, if I’m reading you right, those who argue against the conventional dinosaur – bird interpretation accept feathers on something like Caudipteryx because it’s basically a bird not a theropod dinosaur (in their view). However, with something like Sinosauropteryx they are skeptical of feathers because it undoubtedly is a theropod. Is that basically the line of reasoning?

    If I’ve got this right, what then about Microraptor? I assume no one argues that it is anything other than a theropod dinosaur and the feathers look so convinving to me. What do skeptics say about the feathers in the case of Microraptor?

    Finally, I found from a quick Web of Knowledge search that Lingham-Solair has a new paper out that might help answer some of these questions:

    First investigation of the collagen D-band ultrastructure in fossilized vertebrate integument

    http://journals.royalsociety.org/content/y67q7135118023x5/

    Thanks any answers provided. This is way out of my area of expertise, but if you’ve ever got any questions regarding the Middle Pleistocene, then I’m your man!

  7. 7 David Hone 24/10/2008 at 9:06 pm

    Ah yes of course, I get it all backwards because under these interpreatations, Microraptor and Caudipteryx are flightless birds and not derived theropods! Of couse, my point is still (in a way) valid, becuase if Microraptor and Caudipteryx have feathers, but something like Dilong or Beipiaosaurs does not, I would *love* them to show me what is different between the two! The basic protofeathers of these theropods look identical to those of the alledged ‘flightless birds’ (and of course in plenty of other taxa too). They are all same structure, preserved in the same way. How soem are just degraded collagen and not others is beyond me, and I think, the vast majority of palaeontologists.

  8. 8 Karl Zimmerman 24/10/2008 at 10:14 pm

    Corwin,

    As a layman who understands cladistics, but only has a sketchy understanding of individual skeletal details, this fossil seems to suggest that Scansoriopterygidae is actually basal to a Paraves + Oviraptorosauria clade, not a basal Avialan.

    As you noted in the paper, the skull does have distinct similarities to basal Oviraptorosauria and Therizinosauria. The pubis is also not retroverted. Most interestingly however, it does not have pennaceous feathers – despite these clearly existing in Oviraptorosauria and Deinonychosauria.

    I’m not sure if the presence of different grades of feathers is generally coded as a character, but it seems somewhat strange that the purportedly advanced Scansoriopterygidae would revert to having “intermediate” feathers on its tail and no feathers on its arms, when terrestrial maniraptors with no need for feathers retained them.

    I guess my question is what traits link Scansoriopterygidae and Avialae? I could see a convergent morphology developing due to a similar scansorial habits.

  9. 9 Jerry D. Harris 24/10/2008 at 10:17 pm

    Epidexipteryx also has what we call in the paper elongate tail feathers (ETFs)

    OK, I just have to ask — what the heck is it with the Brits and pointless acronyms?!? Tons of 100% forgettable acronyms were “introduced” and used in SVP talks this year, mostly by people with strong British accents. Is everyone really expected to remember and use these, or are they just some attempt to reduce word counts in submitted manuscripts (in which case I don’t know why they’re proliferating in talks…!)? Just askin’ is all…

  10. 10 David Hone 24/10/2008 at 10:21 pm

    Just to butt in with a rhetorical question to that point Karl, you said “terrestrial maniraptors with no need for feathers retained them”. We don’t know that they had no need for them, and in fact they almost certainly provided a function otherwise they would have been lost. What that function *is* may be a mystery, but it was there and there are several possibilities.

    In fact it seems practical to me for a climbing animal to get rid of those feathers on the arms which would interfere with locomotion in the trees. The tail fetahers are kept (or even expanded) for display, and the body feathers were presumably doing something (insulation, cryptic colouration, brooding even) but those on the arms were not needed and lost (or quite posssibly, simply not preserved). I’ll leave the rest for Corwin.

  11. 11 David Hone 24/10/2008 at 10:26 pm

    Errr Jerry, the first three authors are Chinese and Corwin is Canadian. You wanna retract that whole ‘Brit’ thing? Or were you referring to the Empire ;-)

  12. 12 SteveF 24/10/2008 at 11:02 pm

    Ah yes of course, I get it all backwards because under these interpreatations, Microraptor and Caudipteryx are flightless birds and not derived theropods!

    I didn’t actually realise anyone way saying this about Microraptor, but a quick search informs me that Feduccia has said (Journal of Morphology, 266, 125-166):

    “We suggest that a possible solution to the disparate data is that Aves plus bird-like maniraptoran theropods (e.g., microraptors and others) may be a separate clade, distinctive from the main lineage of Theropoda, a remnant of the early avian radiation, exhibiting all stages of flight and flightlessness.”

    So I guess that these guys aren’t just saying that Caudipteryx isn’t a therapod but also Microraptor too. Learn something new every day I suppose.

    Of couse, my point is still (in a way) valid, becuase if Microraptor and Caudipteryx have feathers, but something like Dilong or Beipiaosaurs does not, I would *love* them to show me what is different between the two! The basic protofeathers of these theropods look identical to those of the alledged ‘flightless birds’ (and of course in plenty of other taxa too). They are all same structure, preserved in the same way. How soem are just degraded collagen and not others is beyond me, and I think, the vast majority of palaeontologists.

    Yes, this argument makes sense to me. As I mentioned earlier, I think the most obvious criticism of the collagen argument is that other, non-dinosaur finds in Liaoning should also show evidence of degraded collagen. As far as I know, they don’t. Which is not even vaguely consistent with the implications of their hypothesis. Parsimony alone would seem to damn them.

  13. 13 Jerry D. Harris 24/10/2008 at 11:11 pm

    Errr Jerry, the first three authors are Chinese and Corwin is Canadian. You wanna retract that whole ‘Brit’ thing? Or were you referring to the Empire

    Teasing, all the way around!

  14. 14 SteveF 24/10/2008 at 11:25 pm

    Sorry, I messed up the html in my post above. The first paragraph is a quote of David as is the penultimate one.

  15. 15 Zach Miller 25/10/2008 at 3:02 am

    Corwin, are you taking requests? I desperately need a copy of the paper so I can restore the little bugger for my blog!

    sillysaur at gmail dot com

    Thanks, brother. Now here’s my only big question: What would this “membraneous” structure be that I keep reading about?

  16. 16 John Jackson 25/10/2008 at 3:16 am

    Points arising from Corwin’s posting…

    “Epidendrosaurus was a kind of dinosaurian aye-aye, a small, possibly arboreal maniraptoran with an elongated third manual digit.”

    As Czerkas et al. show in Czerkas’ book (e.g. p78-79), that extended third finger is associated with traces of very long fibres that could have been feathers. If they were, it wouldn’t have been suitable for aye-aye-ing with. Doesn’t seen reasonable to assume that it did – should just consider it and the alternatives as possibilities.

    “…the rest of the body of Epidexipteryx seems to have been covered only by short, rather fuzzy protofeathers of a kind that are now familiar from several maniraptorans more or less remote from the origin of birds.”

    It was difficult to tell from the paper exactly where the micrographed images were positioned on the fossil. Where do the authors say the “short, rather fuzzy protofeathers” were? And more importantly, where were the things that looked like parallel fibres developing from a flat membrane – those weren’t one of the four streamers. I’m still very interested in finding this out.

    You say Epidexipteryx seems to have been covered only by short, rather fuzzy protofeathers, and what we see in the fossil may just be whispy bits, but similar traces are also seen on NGMC-91 – Dave “cf Sinornithosaurus”. Have a look at this Sinornithosaurus:

    That skeleton is adequate for flight. So we can assume the whispy bits Dave is wearing are the traces of perfectly adequate flight feathers. I think some Confuciusornis flight feathers show up as gossamer whisps too. Those whispy bits on Epidexipteryx may well be suitable for aeronauting, besides the stuff that just didn’t show up at all.

    “But they weren’t going to get Epidexipteryx into the air, so the taxon was evidently neither a flier nor a glider.”

    Not only did feathers that left traces like that get Sinorn. and Conf. into the air, but what purpose can you magine those spindly arms served, if not for aeronauting?! Also, the theory that Epidexipteryx was adapted for aerodynamics explains the short tail; the alternative doesn’t. That’s why the tail is also evidence that it flew or glided. Actually, short tails are perhaps better for flying rather than gliding.

    “…a clade called Scansoriopterygidae that lies immediately basal to Archaeopteryx.”

    When clade S lies immediately basal to a clade A, S will generally give a good clue as the type of thing that A developed from. We also have droms like Microraptor that are very similar to Archaeopteryx. What’s the problem with Scansoriopterygidae -> Archaeopteryx -> droms ??

    For those seeking the solution to the riddle of dinobird evolution, here it is:

    We now have Epidexipteryx to fit in – luckily there is a ready-made place for it, as I find there always is for new discoveries. Any similarities with ovis in the skull are not phylogentically informative. Epidex’ teeth were probably for nibbling insects out of the complex surfaces of the trunks of ‘trees’ of the time.

  17. 17 David Hone 25/10/2008 at 8:47 am

    That;s right Jerry retract it when someone else calls you on it… Oh, and I forgot to add that in the British Army at least they actually have the term TLA which itself is an acronym for Three Letter Acronym since they have so many of them!

  18. 18 Karl Zimmerman 25/10/2008 at 10:44 am

    Dave,

    Of course you’re right that there may have been reasons flightless, non-avian maniraptors kept pennaceous feathers on their arms – including the wastebasket explanation of display, balancing rhea-like when running at high speeds, and brooding eggs. I’ve also read conflicting assertions on if the area around the hands is well-preserved enough to be expected to show pennaceous feathers.

    Provided Scansoriopterygidae lacked “wings” however, this throws a whole toolbox full of spanners into the works of the origin of flight, especially if you think some version of “the trees down” helps explain the origins of flight. If it’s advantageous for “winged” protobirds to lose their pennaceous feathers once they begin climbing, how would a glider evolve anyway (assuming gliding is a required precondition before powered flight)?

    Of course, the scansorial habits of Scansoriopterygidae is likely just a coincidence, especially because Archeopteryx and other primitive birds don’t seem to be particularly good climbers themselves. Still, the potential lack of even behavioral similarities to basal birds returns to my burning question – what characters link Scansoriopterygidae to birds, especially to the exclusion of Deinonychosauria, which, based upon all recent reconstructions I have seen, certainly *look* far more similar to Archeopteryx in overall skeletal proportions.

  19. 19 David Hone 25/10/2008 at 10:56 am

    I’m not sure it does throw a spanner in the works at all, it depends what pressures are affecting different clades. Don’t forget, this is NOT a bird ancestor, despite what many reposts seem to say (non science ones I should be clear) but a close relative of birds, and of course derived in it’s own way. I am really not sure why it’s a problem for some climbing dinosaurs (lets ignore clades for now, it confuses the issue) lived in a relatively open environment where arm feathers were not a hindernace to climbing, and were able to use them to parachute, then glide, and ultimately fly. Another group lived in a much more dense, cluttered environment and these were able to get from tree to tree without jumping, and their arm feathers got caught on all the stray twigs and leaves as it moved around, and so were lost. It was advantageous for some to have arm feathers and not others.

    You get birds living in junglesforests today with every different wing morphologies becuase they are adapted to do different things in different parts of the same environment (like the exceptionally short wing of a wren that can sneak through tiny gaps in foliage through to crows with proportionally much longer wings to fly between patches of woodland).

    As for specific characters, I’ll levae that to Corwin, since that is based on the phylogenetic analysis, and I haven’t seen that yet. I will say however, that often these differences are subtelties and apaprent similarity is not the same as actual similarity (just look at the pachyderms for a great example of this), and of course this only gets more exaggerated when you get such a mess of closely related species. They all look and indeed are very similar, so just a few tiny changes in anatomy can strongly affect the cladistic reconstruction of their relationships.

  20. 20 David Hone 25/10/2008 at 12:30 pm

    With respect to the massive comment above that soemhow claims to solve the riddle of bird evolution, there is not really much I can say except “eh?”. I cannot follow this at all, it is full of non-sequiteurs and misunderstandings. Corwin is welcome to try and disentangle it, but I won’t. One point I will make is that that ‘parallelogram’-tree-thing and the conclusions the author seems to have magically conjoured up are apparently based purely on assumption and phenetics, and not cladistics or any form of actual scientific analysis or consideration of the actual data available. You can’t jsut say that a pathway of Dromaeosaurs-epidendrosaurs-birds is more parsimonious than the reverse, it doesn’t work like that. I have a massive post in preparation on cladistics and a few on concepts like ancestors, and interpreting phylogenetic trees, it looks like they are needed.

  21. 21 Corwin Sullivan 25/10/2008 at 12:52 pm

    Sorry about not replying to comments sooner. I’m actually on the road at the moment, wrapping up a research visit to the collections at the American Museum of Natural History (that’s the AMNH, Jerry), so I’m not getting online to make comment thread checks (CTCs) as often as I would from my office in Beijing (OIB).

    Jaime,
    I still don’t think there’s any good reason to suspect that a large portion of the tail is missing. If scavengers removed a large portion from between the proximal and distal segments, they were fastidious enough to leave the distal portion close to the proximal portion and nearly aligned with it. This doesn’t seem at all likely, especially considering that the anteriormost centra of the distal portion are very close to the centra of the proximal portion in diameter (in contrast to the rapid tapering within the distal portion).

    Karl,
    Dave is absolutely right that characters linking groups in phylogenetic analyses are often subtle. In this case the analysis was carried out by my co-authors, and I don’t have the detailed results with me. However, the paper does mention two characters linking scansoriopterygids to birds, the proportionally long humerus and the large preacetabular process of the ilium (i.e. the part of the pelvis extending forwards from the socket of the hip). With that said, I certainly agree that the lack of flight feathers in scansoriopterygids complicates any storytelling about the origin of flight that one might be tempted to indulge in.

    Zach,
    I won’t speculate as to what membranous structures you might have been reading about! The only ones mentioned in our paper, though, occur at the bases of the non-elongate feathers covering most of the body of Epidexipteryx.

  22. 22 strangetruther 25/10/2008 at 8:55 pm

    @Dave:
    “…it is full of non-sequiteurs and misunderstandings.”

    Don’t you, as a scientist, find complicated things you are not familiar with, interesting? Or do you automatically despise and discard anything new? If you had only detailed one complaint about what I’d written, I’d have been able to start to explain, but you clearly don’t want to understand. Do you want to imply that anyone who’s written something you don’t understand must be an unscientific idiot? …because that’s the message you’re sending your readers.

    “One point I will make is that that ‘parallelogram’-tree-thing and the conclusions the author seems to have magically conjoured up are apparently based purely on assumption and phenetics, and not cladistics or any form of actual scientific analysis or consideration of the actual data available.”

    Do you also want to give the impression that the only scientific approach to this subject is morphology-based parsimony? Two things:

    1: It’s too unreliable to be trusted. Bull et al. (1997), Naylor et al., (2001), and Springer et al. (2008) demonstrated three areas where your “scientific” “cladistics” simply gave completely false results. The latest modern bird analyses also strongly suggest that morphological cladistics doesn’t give anything like good enough answers. Sober (88) gave the definitive theoretical comment on why parsimony is not the final answer. Is their work full of unscientific assumptions? Not only have I read the references above (not quite all of the Sober, obviously :-) ), but I’ve also devised and developed my own cladistics program, to see what can be done to improve the approach. What part of all that do you think demonstrates my judgement on the reliability of morphological cladistics is so far inferior to yours that you don’t need to bother thinking about what I’ve said?

    2: Not only can morph. parsimony *not* be relied on without reservation, but there *are* alternatives for reconstructing the past. But I realise you may not want to hear about them.

    “You can’t jsut say that a pathway of Dromaeosaurs-epidendrosaurs-birds is more parsimonious than the reverse, it doesn’t work like that.”

    I never advocated that sequence or the reverse. And parsimony, and science in general, are more complex than you realise.

    “I have a massive post in preparation on cladistics and a few on concepts like ancestors, and interpreting phylogenetic trees, it looks like they are needed.”

    Please *don’t* tell the public any more about phylogenetics until you have looked at the references I gave above. Much of what you’ve been told about cladistics is wrong, even if all your colleagues in the field that you’ve met, believe in it.

  23. 23 David Hone 26/10/2008 at 9:25 am

    Right OK, so I and all my colleagues and professionals are wrong and you have solved it all? CLadistics has made mistakes and gets things wrong? No surprise there, no method is perfect and cladistitcs far from it, I never said otherwise. However, I will return to my own post on Academic Arrogance about being challenged by people randomly with no authority. I am sorry, but you simply cannot come on here and smugly suggest that you have solved the probelm where all of us have failed on the grounds that cladistics has some problems (oh, and you should perhaps also see my post on poor cladistic analyses).

    I am happy to listen to any suggestions about alternative to morphological parsimony based on cladistic analyses (and for a fossil, I really think you are going to struggle – parsimony is the basis of science, and you these fossil at least can provide nothing but morphological data), but you have not presented anyway, you simply left a link to a tree claiming that *this* was the solution and we all had it wrong? Then suggest I don’t know the literature or methodologies I claim to understand (and indiecentally publish on and teach). Do you have any idea how that sounds to me? Perhaps I don’t know things as well as I think I do or would like to, that is true of almost any scientist, but based apparently on one comment I have left here, I find it entertaining that you have apparently deciphered my abilites and experiences as a researcher.

    When you say “What’s the problem with Scansoriopterygidae -> Archaeopteryx -> droms ??” you are automatically implying that this is more parsimonious than the alternative, which it isn’t, which is why I said it isn’t. Since you claim that this is the correct colution to the problem (or even a reasonable alternative) it must, by defintion be more parsimonious that that suggested. I will leave you will the challenge that I leave all people who provide such statements (and here I include all of your issues on feathers, parsimony, cladistics, bird ancestry and more): get it published. Science is open to everyone. Get your ideas published (you will actually find a guide to publishing a palaeontology paper here on this blog). Write up a paper and get it formally published, don’t sit here tell me I am worng and cladistics is useless, and dromaeosaurs are flightless birds, publish it. The paper Corwin based his post on (and hundreds more supporting these relationships) is published. You have a website. When you have a paper in the literature, and people have evaluated your claims and had the chance to respond in kind in the literature, then you can claim some validity to your work, but not on here.

    Those who know me are aware that I have numerous projects and publications ongoing here and I don’t dicsuss them before they are published. I would not claim (publically, anyway) that my ideas and concepts have any validity until they are in print (and as any researcher will tell you, this is just the start). What you are doing is suggesting that you are right based on a website and we are wrong based on hundreds of peer reviewed papers, and yet you want *me* to stop educating the public. Well amte,. guess what, i will continue to educate the public by explaining the misconceptions attached to science and scientific research becuase that way people will learn. Not many people read my stuff, I’ll admit, but hey a few more I imagine have gained a new perspective on how it all works. And you I can clearly not count yourself among that number: my original comment still stands, you do not know what you are talking about, you read and don’t understand, and don’t want to learn. Fine. Just don’t come here and tell me otherwise.

    Just as an aside to any reader who have struggled through this, you can call me a complete bastard for acting like this, but there is only so much I can take of this stuff (and I am sure many professionals have encountered plenty of it too). I cannot jsut sit forever and be told I am an idito based on a person reading a couple of papers, not understanding the content, the context or both, and then telling me publically that I am a fool, my education wasted, and my colleagues idiots. There are plenty of dedicated amateurs who are genuinely interested and ask for help, take criticism, and try and learn – many even publish papers (it is perfectly possible), but the kinds of flat out statements of rightness based on misunderstanding are hard to take. I probably get more than most becuase of the amount of public communication I do, and thus perhaps I am not the best person suited to the job, but there it is. I do try to help, and many people want to be helped, but not our friend here.

  24. 24 Corwin Sullivan 26/10/2008 at 12:02 pm

    John Jackson (aka Strangetruther?),

    Thanks for an intriguing comment, although I share some of Dave’s perplexity. Just to pick up on a couple of points that he didn’t address:

    1. I wouldn’t necessarily argue that Epidendrosaurus was using its third finger in an aye-aye like manner. Inferences like this about the biology of scansoriopterygids in general are probably going to have to wait for much more detailed functional analysis of the specimens, and even then we can’t necessarily expect to reach firm conclusions. However, the morphological resemblance is pretty striking, at least superficially.

    2. “And more importantly, where were the things that looked like parallel fibres developing from a flat membrane…”

    This describes the microstructure of the non-elongate protofeathers that cover most of the body, although I wouldn’t like to speculate on their precise extent.

    3. I’m not sure I understand the reason for your apparent certainty that Sinornithosaurus was capable of flight. I think it’s more reasonable to assume that the preserved appearance of the “fuzzy” or “wispy” protofeathers reflects their real structure – in both Sinornithosaurus and Epidexipteryx – and that their function was to provide insulation or perhaps to change the appearance of the body. Perhaps even proto-fuzz would have provided a bit of parachuting capability in a small animal like Epidexipteryx, but that’s a far cry from flight or even gliding. Long spindly arms could have many functions other than flight, such as grasping prey, climbing, or even grooming. Similarly, there are other possible reasons for reducing tail length.

    4. On a philosophical note, I would argue that all science ultimately depends on parsimony-based reasoning. Right now, morphological cladistics is the best approach we have for applying the principle of parsimony to the problem of working out the interrelationships of fossil taxa. If you can come up with an equally rigorous methodology that produces demonstrably more reliable results, more power to you – but Dave is correct in saying that the method would need to be published in the peer-reviewed literature and critically evaluated by other researchers before finding wide acceptance.

    5. Not to nitpick, but ovis is Latin for sheep. You must have meant Aves.

  25. 25 Zach Miller 27/10/2008 at 1:10 pm

    Okay, I guess my ultimate question has to do with restoring the little bugger: How should I treat the feathers of the body? Chick-like “fuzz” or ratite-like “brushes?”

  26. 26 John Jackson 27/10/2008 at 7:28 pm

    @Corwin:
    Yes, on the aye-aye finger, best to keep an open mind on grub-hooking or gliding (or…).

    I’d still quite like to know where each comb-like micrograph was placed on the fossil. Their positions at least must be known.

    “I’m not sure I understand the reason for your apparent certainty that Sinornithosaurus was capable of flight. I think it’s more reasonable to assume that the preserved appearance of the “fuzzy” or “wispy” protofeathers reflects their real structure – in both Sinornithosaurus and Epidexipteryx – and that their function was to provide insulation or perhaps to change the appearance of the body.”

    Why should Microraptor be capable of flight, when the very similar Sinornithosaurus, whose distal forelimbs are clearly more robust than its distal hind-limbs, legs as shown by the image:…

    …is supposedly not capable? Of course, I do assume that specialised flight feathers on four limbs indicates flight in Micro :-) .

    This pic of Dave, cf Sinornithosaurus:

    http://paleofreak.blogalia.com/historias/52389

    …shows not only wisps but feather flanges on digit 2.

    If one is going to use parsimony, why not use it in a dead simple situation such as this where we would have to surmise some alternative “activity X” to for using flight-suitable forelimbs, both in the case of Dave and Epidexipteryx. Ditto for shortened tails. As we’re not going to look at a mouth full of knife-like teeth and say “well, it doesn’t have to be carnivory – could indicate some activity ‘Y’”, I think we should be happy to entertain the simplest explanation for flight-suitable adaptations until we have reason to doubt it.

    “On a philosophical note, I would argue that all science ultimately depends on parsimony-based reasoning.”

    Trust me (and a host of others far more qualified than me) Corwin, it doesn’t. Why do you assume Sober 88 can simply be ignored without comment? No professional palaeontologist who has ever lived has ever written anything as clever as that book.

    “Right now, morphological cladistics is the best approach we have for applying the principle of parsimony to the problem of working out the interrelationships of fossil taxa.”

    I don’t know how you can say that when you must have seen me quote the studies that showed how in multiple related fields it just doesn’t work. It has been proved repeatedly not to be reliable. As a scientist you cannot simply ignore those references I gave.

    And there are other ways of using the data contained in the matrices, and in any case there’s also time and geography etc to take into account not to mention functionality.

    “If you can come up with an equally rigorous methodology that produces demonstrably more reliable results,…”

    Trust me on this too, there isn’t any rigour in it. Is there? if so, what? And we don’t need to find anything to improve on something we know can’t be trusted. Not that we can’t find improvements.

    “Dave is correct in saying that the method would need to be published in the peer-reviewed literature and critically evaluated by other researchers before finding wide acceptance.”

    Insisting that a method based on statistical and philosophical insights is judged by people who don’t have research level degrees in those fields would be a waste of time. And even if the method were accepted in a specialist field, the palaeontologists would still block it. The important people are those who understand the issues, and the general public.

    “Not to nitpick, but ovis is Latin for sheep. You must have meant Aves.”
    :-) In Strangetrutherese, ovis means oviraptoroidids or whatever. (Since we’re still discussing the phylogeny, phylogeny-defined group definitions are premature.)

    I very much appreciate the time you’ve taken here, not just because it’s a pretty cool style you’ve taken, but also just as the author of a hot paper :-) .

    Cordially,

    JJ

  27. 27 Corwin Sullivan 28/10/2008 at 4:41 am

    Zach,
    The body feathers are short, and break up into individual strands once beyond the membranous base, so I would think their appearance en masse would be more fuzzy than brushy.

  28. 28 Corwin Sullivan 09/11/2008 at 4:27 am

    John,

    Sorry about taking a little while to reply to your latest comments and questions. I just got back to Beijing from America a few days ago, and I’ve been preoccupied.

    1. If by “comb-like micrograph” you mean “non-elongate feather”, their exact distribution on the body is actually not trivial to determine. Preservation of soft tissue is never perfect, and of course a 3-D animal has been effectively compressed onto a slab. The short, fuzzy feathers cover much of the back and neck, possibly the more ventral parts of the torso, and at least the proximal parts of the limbs. A careful examination under suitable light might provide more detail, and I’m sure we’ll get around to this eventually.

    2. I agree that Microraptor was almost certainly capable of aerial locomotion – though it could have been gliding, rather than powered flight. I don’t believe, however, that anything associated with either manus of “Dave” the Sinornithosaurus can be identified as a flight feather. Well-developed forelimbs could as easily be an adaptation for prey capture, or climbing, as an adaptation for flight. I think the alternative explanations are at least as simple as your flight hypothesis, and therefore at least as parsimonious. (Admittedly, however, this demonstrates that parsimony is only as easy to apply as “simplicity” is to define, in any particular case.)

    3. I’m not “ignoring” Sober’s book – I just happen not to have access to a copy. You’ve certainly piqued my interest, and I’ll try to track down and read his work when circumstances allow. However, I doubt that Sober or anyone else will shift me from the basic position that science is an exercise in picking the simplest hypothesis that explains the available evidence (i.e. that has not been falsified). The criterion of simplicity is synonymous with parsimony in the broad sense that I would use the term.

    4. Surely it’s an exaggeration to say that “there isn’t any rigour in” cladistics. Cladistics is rigorous to the extent that you take information about a set of taxa and process that information using an explicitly stated algorithm to arrive at an estimate of phylogenetic relationships. Palaeontologists who use cladistics are acutely aware of the shortcomings of the approach – particularly the subjectivity of defining morphological characters in the first place, and the problem of being unable to integrate stratigraphic, functional and other information (although not everyone would agree that this is a good idea). A better method, a broader method that found practical ways to incorporate other sources of evidence and eliminate the remaining subjectivity, would be more than welcome. However, it would have to be ultimately based on parsimony, again in the broad sense I set out above.

    5. I would suggest that it’s both counter-productive and a bit patronising to argue that methods for sorting out relationships among fossil taxa should not be tested and evaluated by palaeontologists – the people who will apply these methods, and become intimately familiar with them in the process. Some palaeontologists have a very good grasp of statistics and/or philosophy, although of course help from full-time professionals in these fields is always going to be welcome. Palaeontologists won’t “block” anything that can be shown to produce helpful results – why on Earth would we?

    6. Thanks for the lesson in Strangetrutherese!

  29. 29 David Hone 09/11/2008 at 6:03 pm

    Just to add a bit more on Microraptor vs ‘Dave’ (the fossil and probably Sinornithosaurs, not me) and flight. There are a couple of good reasons for thinking the former could not glide – the skeleton is generally more robust and the arms are much shorter being a good start. Most notably, there are no flight feathers – there are much larger and more robust (think of the rachis if nothing else) than the body coverings, so if these small ‘fuzzy’ proto-feathers are present and yet no other preserve then they probably weren’t there. When you consider that we actually have several specimens and none of them show flight feathers when several have fuzz, then we can hardly argue that they are misisng by chance.

    As for the supposed lack of geographical, functional and temporal data in cladistics, actually these are used, if rarely. The problem lies with integrating them in a suitable manner, but this is an issue for the operators (i.e. the scientists) and not one of the methodology. Cladistics can incorporate this data, just becuase it is not used is no fault of the analysis. It is also used in linguistics and geology, so clearly can account for more than just anatomy and morphology (and of course more fields working on cladistic methodology and application). Similarly, there has been a general trend to remove subjectivity from characters in analysis and while this is difficult and exceptionally time consuming it has been done (see my post of stegosaur phylogeny).

  30. 30 John Jackson 19/11/2008 at 10:58 pm

    Corwin-

    Sorry for the delay. Back in China now then! Do you know of any good recent photos showing uncinate processes in Confuciusornis? Now your co-author Zhonghe Zhou has recanted I think it’s back to me being the only one to believe they don’t exist. They still can’t be photographed though.

    Addressing your sections…

    1. What I’m asking for is an indication – a tiny square or perhaps an arrow – of where on the big photo (as seen at the top of this web page) each of the photomicrographs were taken, just as the ‘ “bean-sized” conchostracan specimens’ are indicated in the supplementary material. I’m not asking how much of the fossil is covered by that sort of feather.

    2. I’m not saying anything on the “Dave fossil” itself has the appearance of a flight feather, but that doesn’t mean it didn’t have them. Ichthyornis has no traces of feathers. If however “Dave” could at least glide as you say, it must have had feathers, since it’s inconceivable something so similar to Microraptor got lift but not through feathers.

    3. Sober’s “Reconstrucing the Past” is probably out of print. Google on:
    priest-chunkled
    for the preface. I wouldn’t recommend reading the book, but I would recommend not saying palaeontology is all about parsimony unless you have good counter-arguments to Sober’s.

    >However, I doubt that Sober or anyone else will shift me from the basic position that science is an exercise in picking the simplest hypothesis that explains the available evidence (i.e. that has not been falsified).
    A better method, a broader method that found practical ways to incorporate other sources of evidence and eliminate the remaining subjectivity, would be more than welcome. However, it would have to be ultimately based on parsimony, again in the broad sense I set out above.
    5. I would suggest that it’s both counter-productive and a bit patronising to argue that methods for sorting out relationships among fossil taxa should not be tested and evaluated by palaeontologists – the people who will apply these methods, and become intimately familiar with them in the process.

    Some palaeontologists have a very good grasp of statistics and/or philosophy, although of course help from full-time professionals in these fields is always going to be welcome.

    Palaeontologists won’t “block” anything that can be shown to produce helpful results – why on Earth would we?
    <

    Because palaeontologists have such a disdain for other people’s ideas on philosophy of science and such confidence in their own, they do not have three criteria for theories:

    their own theories;

    theories based on bad science;

    theories based on good science but differing from their own theories.

    Instead they have just two, omitting the third, and so they feel entitled to damn any contributions they don’t like, without bothering to give any valid reason: “La Science? C’est moi :-]” They think science is their private property, which is a more serious mistake than they realise.

    If I write any more I won’t need to write the book!

    Cheers,

    JJ

  31. 31 David Hone 22/11/2008 at 11:09 am

    Ok, I’ll try and deal with this very breifly.

    Point 2: I have already explained why “Dave” and others almnost certainly do not have flight feathers. And no-one has said it is capable of flight / gliding except you. It could not fly. It could not glide.

    Point 5: You seem convinced there is some great palaeontological conspiracy, or at least a general distain for anything but our own research. Once more I suggest you get those ideas published rather than bleating on here about how terrible / useless / arrogant we all are. If the problem (as you claim) lies with our interpreataion of the philosophy of science then present it. Write a paper or present a talk at a meeting, or even just register to a meeting and then talk to people there. This is not the forum for such discussions. You seem to know an awful lot about all palaeontolgists for someone who as far as Ic an tell has never been to a meeting or published a paper. There are plenty of people in the UK who have worked on the philosophy of science, the applciations and indeed philosphy of cladistic methods and are palaeontolgoists. Talk to them rather than posting here and publically accusing us of ignorance and parochialism.

    I hate to end it like this, but I’m not goign to accept any more comments on this vein. Look at the fossils, do the research, publish the results. Those are the rules everyone plays by. Play by them.


  1. 1 Hairy Museum of Natural History » Epidexipteryx hui Trackback on 24/10/2008 at 10:39 pm
  2. 2 No ado about much – new dinosaur footprints from China « Dave Hone’s Archosaur Musings Trackback on 16/12/2008 at 9:09 am
  3. 3 Yes it’s more theropod photos « Dave Hone’s Archosaur Musings Trackback on 22/12/2009 at 9:04 am
  4. 4 Guest post: Birds in a flap thanks to dinosaur wrists « Dave Hone’s Archosaur Musings Trackback on 03/03/2010 at 8:07 am

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