Re: Feathering proof

[tyrantqueen]

Oh, and I forgot to mention: it was said that the Dakota specimen showed traces of striping along the tail. If the animal was covered in feathers, wouldn't the skin be devoid of any patterns, because the fuzz on top would be decorated?

Just a thought.

[amargasaurus cazaui]

Just anted to chime in and say that it looks like the "quills" of Tianyulong and Psittacosaurus probably are feathers after all, or at least homologous with them. Feathers in modrrn birds take on a variety of forms. Turkeys, for example, have quill-like "beard" feathers that evolved from normal feathers. It's possible this is what the "quills" are in certain ornithischians.

Also, keep an eye on the news in the next few weeks. There is a major new fossil bed found in Siberia that is just as good as the famous ones in China for producing feathered dinosaurs. The first of these is set to be presented at SVP next week and published shortly after.

It's an ornithischian with true feathers, not just quills.

So, there's that.

If early reports are correct, it would mean all dinosaurs evolved from feathered ancestors and that the "pycnofibers" of pterosaurs are probably just simple feathers, too. This could be the most important dino discovery since Sinosauropteryx!

But wait, don't some dinos have scales? of course, all dinos have sclae,s including birds, on various parts of the body. But as we see in the Jehol fossils, scales and feathers require different conditions to fossilize. Almost all feathered dinosaurs do not preserve even a trace of scales, even though we know they must have had them, at least on the feet. Most scaly dinosaurs preserve no trace of feathers. We used to assume this was because they had no feathers, but it should be clear by now that it's really just because they almost never fossilize side by side. Surely all feathered dinosaurs had at least small patches of scales and many large, scaled dinosaurs probably had at least sparse feathering.

Think Armadillos and glyptodonts. Many glyptodonts preserve really nice moulds of the shell texture, but no trace of the hair they almost certainly had covering it and filling in the cracks. Actually, that's not entirely true--some glyptodont osteoderms have peculiar channels in them that are thought to be where blood vessels fed the hair and it was anchored. Weirdly, ankylosaurs have very similar structures...

Your comment about the fossil beds and feathered dinosaur I found most interesting. Are you able to state the approximate age of the fossil trove? I am in particular interested in this comment...."It's an ornithischian with true feathers, not just quills." Are you at liberty to discuss the specimen further? I would assume the dinosaur would then be late jurassic or earlier....Can you elaborate on the exact species or family....etc? thanks....amazing information

[Patrx]

Fascinating! I look forward to seeing what we can learn from this.

Oh, and I forgot to mention: it was said that the Dakota specimen showed traces of striping along the tail. If the animal was covered in feathers, wouldn't the skin be devoid of any patterns, because the fuzz on top would be decorated?

Just a thought.

I wouldn't necessarily think so. Aren't most body patterns visible on the skin underneath the feathers/fur on modern animals?

[tyrantqueen]

Fascinating! I look forward to seeing what we can learn from this.

Oh, and I forgot to mention: it was said that the Dakota specimen showed traces of striping along the tail. If the animal was covered in feathers, wouldn't the skin be devoid of any patterns, because the fuzz on top would be decorated?

Just a thought.

I wouldn't necessarily think so. Aren't most body patterns visible on the skin underneath the feathers/fur on modern animals?

I did a google search for "featherless bird". Every single bird that I looked at that was featherless had no indication of body pattern on any of them.







This was sad to look at

[wings]

...Almost all feathered dinosaurs do not preserve even a trace of scales, even though we know they must have had them, at least on the feet. Most scaly dinosaurs preserve no trace of feathers. We used to assume this was because they had no feathers, but it should be clear by now that it's really just because they almost never fossilize side by side...

Just to add we do have example(s) which has both "feathers" and "scales" preserved on the same animal. One of the more well known one is "Dave" the Sinornithosaurus (http://qilong.wordpress.com/2010/07/21/my-friend-dave/, http://www.mos.org/sites/dev-elvis.mos.org/files/docs/press-kits/2011060115._Sinornithosaurus_fossil.JPG). Caudipteryx NGMC 97-4-A (http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC8QFjAB&url=http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F32013491_Two_feathered_dinosaurs_from_northeastern_China%2Ffile%2Fd912f5073385492494.pdf&ei=KHljUonmCqP_iAeQvYHgCg&usg=AFQjCNFU_bBDh0vckAj4GjwJgtQdf4SmuQ&bvm=bv.54934254,d.aGc&cad=rja) maybe a second example, it has scales(?) or naked skin(?) (could be wrong since that was based on memory of something I read a long time ago) preserved on the fleshy pads of its wing digits.

[Dinoguy2]

Your comment about the fossil beds and feathered dinosaur I found most interesting. Are you able to state the approximate age of the fossil trove? I am in particular interested in this comment...."It's an ornithischian with true feathers, not just quills." Are you at liberty to discuss the specimen further? I would assume the dinosaur would then be late jurassic or earlier....Can you elaborate on the exact species or family....etc? thanks....amazing information

I don't have many details other than what is in the SVP abstract, the paper is due to be published in a month or so and a ton more info will be out then. Here's an article about the initial discovery of the site: http://permalink.gmane.org/gmane.science.dinosaurs.general/57600

The age of the new formation is middle-late Jurassic, about the same as the Tiaojishan formation that gave us Anchiornis, Tianyulong, Darwinopterus, etc. Based on early news reports on the site they have also found numerous small theropods with hind wings as well as some new compsognathids. I'm betting we see a lot of new species described from here starting next year.

The new feathered ornithischian is described as a basal neornithischian, basically what used to be known as a "hypsilophodontid". It has both feathers and crocodile like scales. The tail is covered in scales, some interspersed with feathers, with feathers covering the front part of the body. This is a picture of Orodromeus based on preliminary reports of the new species' feathering: http://tomozaurus.deviantart.com/art/Mountain-Runner-402497022

If early reports are correct, it would mean all dinosaurs evolved from feathered ancestors and that the "pycnofibers" of pterosaurs are probably just simple feathers, too. This could be the most important dino discovery since Sinosauropteryx!

Now, I believe that dinos had feathers just as much as the next guy, but how the heck does one fossil bed prove that "all dinosaurs evolved from feathered ancestors"? Not saying that this statement isn't true, but, again, how the heck does one find prove that? That's faulty logic. I'm sure there were some dinos with no feathers, and making this huge statement with little evidence seems to me irrational. Could you enlighten me?

One fossil bed proves nothing. what offers proof is the fact that an ornithischian has true feathers. It is far, far more likely that dinosaurs evolved from a single feathered animal than the idea that a complex structure like true feathers evolved twice, once in coelurosaurs and once in ornithischians. Feathers may then have been reduced or even lost completely in certain lineages, but see below...

I know I've said this before, so sorry for repeating myself: what about the "mummified" hadrosaurs? For me, they are definite proof that hadrosaurs, at least, were not feathered. Surely, if the muscles, scales, and inter vertebral discs were preserved, feathers/fuzz would have been too?

What on earth makes you think that? Here's a picture of a mammoth mummy:

Clearly, this is proof baby wooly mammoths had no hair!

People, including professional scientists, need to do a lot more work studying taphonomy, the science of how things decompose. If more people realized that the appearance of an animal can change drastically very shortly after death, we wouldn't have people going on about "Montauk Monster" type stories every other month... Misunderstanding of taphonomy by scientists is where the myth of "protofeathers" came from from (coeluosaurs like Sinosauropteryx have branched feathers, on close inspection, but because they got smooshed together they look line unbranched structures. Foth demonstrated this sort of thing years ago yet people still talk about "protofeathers" in these animals).

Feathers basically need to be preserved in 2D slabs in order to be preserved at all. A 3D mold will usually not preserve hair-like structures of any kind--they're just too soft to make an impression in that way, and they tend to fall off fast when an animal is submerged in water and then dried out, as happened in hadrosaur mummies, the Montauk monster raccoon, etc. That's why feathers are only preserved in 1 out of a thousand psittacosaurs specimens (most are preserved in 3D due to burial, finding one on a slab is very rate since they were burrowers) and why the only evidence of feathers in any Canadian species comes from an ornithomimid preserved in very fine silt with not a trace of any other soft tissue. If we ever found an Avisaurus mummy, I do not believe it would be likely to preserve any trace of feathers. That's just not how decomposition and fossilization work.

Either way, it's entirely possible hadrosaurs had no feathers, or a sparse covering of filaments between the scales that would let the skin show through (again, see armadillos, pangolins, glyptodonts, etc.). But the evidence now appears irrefutable that their ancestors had a substantial amount of feathers.

As for the striped tail pattern, none of the featherless birds pictures have feather patterns (they were all white birds!) so that's not much for evidence. Also, it's entirely possible that advanced species like hadrosaurs lost some or all feathers, which doesn't negate the fact they evolved from a feathered ancestor.

[amargasaurus cazaui]

That is just incredible, and the potential for new species is really endless. I am excited to watch this set of developments, because it makes much more sense than the concept of feathered dinosaurs being exclusive to one side of the family tree. I hope to see much more about this find.

[wings]

I know I've said this before, so sorry for repeating myself: what about the "mummified" hadrosaurs? For me, they are definite proof that hadrosaurs, at least, were not feathered. Surely, if the muscles, scales, and inter vertebral discs were preserved, feathers/fuzz would have been too?

What on earth makes you think that? Here's a picture of a mammoth mummy:

Clearly, this is proof baby wooly mammoths had no hair!

Is this the same specimen?



From the image above we can clearly see that there is hair/fur partially covering its limbs (http://donsmaps.com/bcmammoth.html, here is a quote from the page: "...With her trunk still intact, eyes in place and small tufts of fur still on her skin, Lyuba looks more like a museum fake than a link to life in the Ice Age..."). I think why most people are suggesting when they use the hadrosaur mummies as examples is because we have never positively identified any integuments other than "scales" associated with the animals. Unfortunately mammoth probably is not the best example to state your point...

[HD-man]

Just to add we do have example(s) which has both "feathers" and "scales" preserved on the same animal. One of the more well known one is "Dave" the Sinornithosaurus (http://qilong.wordpress.com/2010/07/21/my-friend-dave/, http://www.mos.org/sites/dev-elvis.mos.org/files/docs/press-kits/2011060115._Sinornithosaurus_fossil.JPG). Caudipteryx NGMC 97-4-A (http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC8QFjAB&url=http%3A%2F%2Fwww.researchgate.net%2Fpublication%2F32013491_Two_feathered_dinosaurs_from_northeastern_China%2Ffile%2Fd912f5073385492494.pdf&ei=KHljUonmCqP_iAeQvYHgCg&usg=AFQjCNFU_bBDh0vckAj4GjwJgtQdf4SmuQ&bvm=bv.54934254,d.aGc&cad=rja) maybe a second example, it has scales(?) or naked skin(?) (could be wrong since that was based on memory of something I read a long time ago) preserved on the fleshy pads of its wing digits.

Don't forget about Juravenator ( http://en.wikipedia.org/wiki/Juravenator#Feathers_and_scales ).

[Patrx]

Fascinating! I look forward to seeing what we can learn from this.

Oh, and I forgot to mention: it was said that the Dakota specimen showed traces of striping along the tail. If the animal was covered in feathers, wouldn't the skin be devoid of any patterns, because the fuzz on top would be decorated?

Just a thought.

I wouldn't necessarily think so. Aren't most body patterns visible on the skin underneath the feathers/fur on modern animals?

I did a google search for "featherless bird". Every single bird that I looked at that was featherless had no indication of body pattern on any of them.

Interestingly, I did the very same Google search before posting my initial question, just to check - but like you, I couldn't find any featherless versions of birds with distinct patterns. I'm fairly sure the skin of a raccoon or similar animal reflects the patterns seen in its hair, but it's possible that this isn't so with feathers. In any case, while I'm not convinced that hadrosaurs were feathery, I'm also not convinced that they weren't 

[Dinoguy2]

I know I've said this before, so sorry for repeating myself: what about the "mummified" hadrosaurs? For me, they are definite proof that hadrosaurs, at least, were not feathered. Surely, if the muscles, scales, and inter vertebral discs were preserved, feathers/fuzz would have been too?

What on earth makes you think that? Here's a picture of a mammoth mummy:

Clearly, this is proof baby wooly mammoths had no hair!

Is this the same specimen?



From the image above we can clearly see that there is hair/fur partially covering its limbs (http://donsmaps.com/bcmammoth.html, here is a quote from the page: "...With her trunk still intact, eyes in place and small tufts of fur still on her skin, Lyuba looks more like a museum fake than a link to life in the Ice Age..."). I think why most people are suggesting when they use the hadrosaur mummies as examples is because we have never positively identified any integuments other than "scales" associated with the animals. Unfortunately mammoth probably is not the best example to state your point...

Maybe not, but my point is that taphonomy matters. This is a specimen of an animal that we know was covered head to toe in dense hair and, before even being fossilized, 99% of it is not visible. Turn the surrounding matrix to rock and you probably would not even see that. My point is that mummies are bad metric for seeing how much hair/filaments something had.

[wings]

Maybe not, but my point is that taphonomy matters. This is a specimen of an animal that we know was covered head to toe in dense hair and, before even being fossilized, 99% of it is not visible. Turn the surrounding matrix to rock and you probably would not even see that. My point is that mummies are bad metric for seeing how much hair/filaments something had.

Yes, taphonomy matters but at the same time hair or fur does sometimes "fossilize" such as impression or carbon imprints (and that is what some people are getting at as we haven't had any luck on finding "feather" imprints on any hadrosaurians yet...).



All I'm saying is mammoth is probably a bad example.

[tyrantqueen]

Does this mean that models of Psittacosaurus with tail bristles are wrong? What should the animal be covered in, instead? Should it be covered with feathers from head to toe? Thanks.

[Patrx]

Does this mean that models of Psittacosaurus with tail bristles are wrong? What should the animal be covered in, instead? Should it be covered with feathers from head to toe? Thanks.

I've been wondering about that, too. After all, all the fossil proves is that the animal had filaments on its tail; not that it didn't have filaments elsewhere, right?

[wings]

I know I've said this before, so sorry for repeating myself: what about the "mummified" hadrosaurs? For me, they are definite proof that hadrosaurs, at least, were not feathered. Surely, if the muscles, scales, and inter vertebral discs were preserved, feathers/fuzz would have been too?

Just in case if you haven't seen this; this paper might be some interest to you http://www.app.pan.pl/article/item/app20120077.html.

[tyrantqueen]

Just in case if you haven't seen this; this paper might be some interest to you http://www.app.pan.pl/article/item/app20120077.html.

That was an interesting read, thank you.

[Dinoguy2]

Does this mean that models of Psittacosaurus with tail bristles are wrong? What should the animal be covered in, instead? Should it be covered with feathers from head to toe? Thanks.

It means we have no idea. We know Psittacosaurus had at least feathers on the top of the tail, and we know that these structures fall off quickly after death, especially death under water. It may have had more feathers, but we need more slab-preserved specimens to know.

The take-home message from all this should be that we really are only just starting to get the first clue what most dinosaurs looked like, and may never know for sure for 99% of them, even when it comes to major things like what their skin was covered with, and EVEN when we have "well preserved" specimens like slabs and fossil mummies. Those things are "well preserved" compared to other fossils, which are usually just bones, but they are in no way "well preserved" compared to a living animal.

Mummies and slab specimens look more 'natural' but it's very, very important to remember that these are not snapshots of living animals from the past--they're snapshots of half-rotten carcasses from the past.

[HD-man]

Your comment about the fossil beds and feathered dinosaur I found most interesting. Are you able to state the approximate age of the fossil trove? I am in particular interested in this comment...."It's an ornithischian with true feathers, not just quills." Are you at liberty to discuss the specimen further? I would assume the dinosaur would then be late jurassic or earlier....Can you elaborate on the exact species or family....etc? thanks....amazing information

I too am most interested, which is why I looked up the SVP 2013 abstracts ( http://vertpaleo.org/PDFS/0d/0d20d609-f7e6-4bb3-a0c4-765fcffde49b.pdf ). The 1st of the following quotes is the abstract Dinoguy2 has been referring to (Page 135). However, it doesn't actually say that the new neornithischian has "true feathers, not just quills". Rather, it says that 1) "varied integumentary structures were found directly associated with skeletal elements," & 2) said structures support "the hypothesis that simple filamentous feathers, as well as compound feather-like structures comparable to those in theropods, were widespread amongst the whole dinosaur clade." I'll wait for the paper (& its reviews) before forming an opinion, but from the looks of it, said structures are no more feather-like than previously known ornithischian quills & the authors are just using the discovery of another quilled ornithischian as reason to synonymize ornithischian quills with protofeathers. The 2nd of the following quotes (Page 82) is equally relevant b/c (if I'm right about said structures) it shows that 1) ornithischian quills "are best regarded as autapomorphic integumentary modifications", & 2) "theropods are currently the only dinosaurs that display unequivocal evidence of feathers and their direct homologs."

Symposium 4 (Saturday, November 2, 2013, 9:30 AM)
FEATHER-LIKE STRUCTURES AND SCALES IN A NEORNITHISCHIAN DINOSAUR FROM SIBERIA
JURASSIC
GODEFROIT, Pascal, Institut Royal des Sciences Naturelles de Belgique, Brussels, Belgium; SINITSA, Sofia, Institute of Natural Resources, Ecology and Cryology, SB RAS, Chita, Russia; DHOUAILLY, Danielle, Université Joseph Fournier, La Tronche, France; BOLOTSKY, Yuri, Institute of Geology and Nature Management, FEB RAS, Blagoveschensk, Russia; SIZOV, Alexander, Institute of the Earth's Crust, SB RAS, Irkutsk, Russia
Recent discoveries in Middle–Late Jurassic and Early Cretaceous deposits from northeastern China have revealed that numerous theropod dinosaurs were covered by feathers. Furthermore, filamentous integumentary structures were also recently described in rare Early Cretaceous ornithischian dinosaurs from Liaoning Province in China. Whether these filaments can be regarded as epidermal and therefore part of the evolutionary lineage towards feathers remains controversial. Here we describe a new basal neornithischian dinosaur, based on isolated bones and partial skeletons collected in two monospecific bonebeds from the Middle–Late Jurassic Kulinda locality in the Transbaikal region (Russia). Varied integumentary structures were found directly associated with skeletal elements, supporting the hypothesis that simple filamentous feathers, as well as compound feather-like structures comparable to those in theropods, were widespread amongst the whole dinosaur clade. Moreover, scales along the distal tibia and on the foot closely resemble the secondarily-appearing pedal scales in extant birds. More surprisingly, dorso-ventral movements of the tail were prevented by large imbricated scales on its dorsal surface. It is hypothesized that, at the same time early feathers evolved within the whole dinosaur clade, genetic mechanisms limiting the growth of long epidermal structures on the distal portion of the hind limb and on the tail were selected as they facilitate bipedal terrestrial locomotion.

Poster Session III (Friday, November 1, 2013, 4:15 - 6:15 PM)
DINOSAUR INTEGUMENT: WHAT DO WE REALLY KNOW?
BARRETT, Paul, The Natural History Museum, London, United Kingdom; EVANS, David, Univ of Toronto at Mississauga, Toronto, ON, Canada
Osteoderms and scaly skin impressions are historically well known in non-avian dinosaurs. Recent discoveries have demonstrated that in addition to these structures, many dinosaur taxa possessed other integumentary features, including a range of 'quills,' filaments, and feathers in non-avian theropods and ornithischians. Feathers and their homologs are commonly regarded as a synapomorphy of either coelurosaurian or tetanuran theropods, but some authors have gone further, using the presence of ornithischian feather-like structures to suggest that these structures are plesiomorphic for Dinosauria. This inference has wide-ranging implications for dinosaur biology and evolution.
However, to date, no studies have attempted to assess rigorously the evolution of dinosaur integumentary structures within a broad phylogenetic context. We compiled a complete database of all epidermal integumentary structures reported in dinosaurs, by major body region, in order to investigate the origin of feather homologs and the evolution of integumentary structures in the clade. Scales are definitively present in virtually all major ornithischian clades. This, and the presence of extensive armour in thyreophorans suggests that genasaurian skins were primitively scaly. Similarly, sauropodomorphs lack evidence for anything other than scales or osteoderms. Fitch optimization of integument types on dinosaur phylogenies shows that there is no unequivocal support for inferring a deep origin of feather-like structures, a result supported by maximum likelihood ancestral state reconstructions for these characters. The structures in Tianyulong and Psittacosaurus are best regarded as autapomorphic integumentary modifications, and there is currently no strong evidence that these features are feather homologs. Further work on the chemical composition of these structures, and those in several non-coelurosaurian theropods, is needed. Although ornithodirans exhibit a range of integumentary novelties that may be related to the origin of feathers, theropods are currently the only dinosaurs that display unequivocal evidence of feathers and their direct homologs.

[wings]

It means we have no idea. We know Psittacosaurus had at least feathers on the top of the tail, and we know that these structures fall off quickly after death, especially death under water. It may have had more feathers, but we need more slab-preserved specimens to know.

Looking back on this specimen; it is clear that there is no preservation bias towards either scales or feathers (since we found both on this specimen) but what seems unusual about this is that we did not have any "quills" (not a single trace of it) found on this animal apart from what is preserved on the top of the tail. So I guess what needs to happened to have this kind of preservation is that the animal would require to lose "all" it quills on the underside before the body pressed down on the sediment if I'm following your line of reasoning. I'm just not certain how realistic would it be?

[Dinoguy2]

said structures support "the hypothesis that simple filamentous feathers, as well as compound feather-like structures comparable to those in theropods, were widespread amongst the whole dinosaur clade." I'll wait for the paper (& its reviews) before forming an opinion, but from the looks of it, said structures are no more feather-like than previously known ornithischian quills & the authors are just using the discovery of another quilled ornithischian as reason to synonymize ornithischian quills with protofeathers. The 2nd of the following quotes (Page 82) is equally relevant b/c (assuming I'm right about said structures) it shows that 1) ornithischian quills "are best regarded as autapomorphic integumentary modifications", & 2) "theropods are currently the only dinosaurs that display unequivocal evidence of feathers and their direct homologs."

It's wise to wait for the published paper, but two things. One, the statement that they are compound structures means they are more like feathers than known ornithischian quills. Feathers are compound (made of more than one filament), currently-published ornithischian quills don't appear to be. So saying that they're the same as known quills is wrong.

Two, the Barrett abstract you quote is irrelevant, as it's presented in the same volume. Barrett and co-authors could not have included any information from the new ornithischian in their study.

It means we have no idea. We know Psittacosaurus had at least feathers on the top of the tail, and we know that these structures fall off quickly after death, especially death under water. It may have had more feathers, but we need more slab-preserved specimens to know.

Looking back on this specimen; it is clear that there is no preservation bias towards either scales or feathers (since we found both on this specimen) but what seems unusual about this is that we did not have any "quills" (not a single trace of it) found on this animal apart from what is preserved on the top of the tail. So I guess what needs to happened to have this kind of preservation is that the animal would require to lose "all" it quills on the underside before the body pressed down on the sediment if I'm following your line of reasoning. I'm just not certain how realistic would it be?

Extremely realistic. It would be unrealistic to think it did not decompose at all before burial/fossilization, seeing that it was submerged in water first.

http://www.montauk-monster.com The Montauk Monster is a good example because this is an animal carcass in the water probably only for a few days before being washed up and partially buried, yet when found most people could not recognize it ands it took experts to identify it as a raccoon. And this is a fresh carcass, not even a fossil, the process of which would inevitably add even more distortion.

People have this idea that the feathered dinosaurs were preserved that way because they were buried quickly by a volcano. Not true--the Lujiatun beds are the "Dino Pompeii" of China that preserve things like Mei long in great shape but with no soft tissue. The lake sediments are a standard lagerstatten that happened to be formed by silt left over from those same and subsequent volcanos, but those animals still died and sank to the bottom of the lake first, which took time. When animal carcasses get soaked with water, soft stuff starts falling off very quickly.

This is one reason big primary feathers are almost always better preserved in dinobirds than the body covering. As Hone et. al showed, the primaries are more strongly attached. Look up photos of soaked or even desiccated bird carcasses, you'll often find they're just skeletons with wing feathers still attached!

Taphonomy - the study of how animals decay under different conditions. Very important for interpreting fossils, yet almost always ignored.