PSA: Anchiornis feet were scaly AND fully feathered

[Dinoguy2]

The new paper on the soft tissue of Anchiornis shows an amazing and not totally unexpected result:

Scales covering the feet all the way up to the lower tibia.

http://www.skeletaldrawing.com/home/anchiornissofttissue

So while we have unequivocal proof that Anchiornis had pennaceous feathers covering its feet and toes, we now also have unequivocal proof that there were standard dinosaurian scales under those feathers.

So I never want to hear that scales are evidence against feathers or feathers are evidence against scales again

[Patrx]

Wow! How exciting. I wonder, does this mean that preserved impressions of reticulae could be from parts of a dinosaur's body that also had filaments?

[Cloud the Dinosaur King]

Wow! How exciting. I wonder, does this mean that preserved impressions of reticulae could be from parts of a dinosaur's body that also had filaments?

Maybe even Tyrannosaurus rex!

[Faelrin]

That was a very nice read. I absolutely love when more integument is discovered and/or studied. Aside from the foot scales and feathers thing (although aren't modern birds the same or similar in that regard, or am I misunderstanding?), I thought it was interesting it had a patagium on its arms like modern birds, and the bird like skin as well. One little thing I am confused about is the lower two finger digits. Are they separate digits like our fingers are or are they more together in a fleshy mitten? Would they be similar to how an ostrich wing is with its exposed claws, if the "fleshy mittens"?

[Loon]

Absolutely fantastic, the presence of the patagium on the arms wasn't too shocking. However, I do wonder how widespread it was in maniraptors, or more generally, if it was an ancestral feature in all dinosaur lineages? Also, like Faelrin, I do wonder if the second and third digits were fused by a skin covering.

[ZoPteryx]

Very cool research indeed!

My impression of manual digits II and III is that they were mostly fused, and even if the very ends were separated, they wouldn't have been very mobile.  Still, the hand was probably more flexible overall than that of a modern bird.

The propatagia is equally interesting, could it suggest it original served a non-flight related function?  Or was Anchiornis really a flyer and we just haven't realized it yet?

And the detail on those foot pads is superb!  Neat how they fit under the joints, as in modern birds, rather than between them, as in mammals.  That's something I'd honestly never even thought about! 

So I never want to hear that scales are evidence against feathers or feathers are evidence against scales again

This! 

[DinoLord]

After reading that all I could think of was how Anchiornis wings would've tasted... 

[Cloud the Dinosaur King]

After reading that all I could think of was how Anchiornis wings would've tasted... 

Very funny

[The Atroxious]

I am decidedly unsurprised by this information. I've been saying for years that wings don't make sense without flesh on the fingers and propatagia, and this basically just vindicated my postulations.

I will say though, I expected there to be more flesh on the posterior of the ulna as a support for the feathers. Perhaps it didn't need that extra support, but I'm so used to seeing bird anatomy that I expected the arm to be shaped like the arm of a bird.

[HD-man]

Maybe Anchiornis was doing something similar to ptarmigans (See "FIGURE 1": https://sora.unm.edu/sites/default/files/journals/condor/v079n03/p0380-p0382.pdf ).

[stargatedalek]

Haven't we seen this in modern birds so many times before? It's a trait that can even be bred into them (pigeons and chickens both confirm this). I really don't get how this is big news. That the trait is present on groups that are far removed from each other also always implied this dated back at least to when we first saw this form of scaling appear on the feet.

Interesting to see it present 100% this far back, but still.

[Dinoguy2]

I am decidedly unsurprised by this information. I've been saying for years that wings don't make sense without flesh on the fingers and propatagia, and this basically just vindicated my postulations.

I will say though, I expected there to be more flesh on the posterior of the ulna as a support for the feathers. Perhaps it didn't need that extra support, but I'm so used to seeing bird anatomy that I expected the arm to be shaped like the arm of a bird.

If you read the paper linked in the article they actually discuss this. There is some material behind the ulna that might be a pretty substantial postpatagium but it's hard to tell with all the feathers there.

To answer other questions in the thread: yes, the second two fingers were attached in a fleshy mitten. The propatagium has also been found in Caudipteryx, Scansoriopteryx, Archaeopteryx, and Microraptor, so it was probably common to maniraptorans. There is evidence that other maniraptorans also has connected fingers, especially in some oviraptorosaurs, and this might explain why some species reduce or lose digit 3, like in Caudipteryx.

[Neosodon]

So this means that T Rex could of shed its feathers as it grew up or to adapt to a climate. That was an old theory that was disproved because scales supposedly couldn't exist under feathers. This find opens up so many possibilities for therapods. Having scales and feathers both would make them very adaptive to changing climates or extreme seasons.

[Cloud the Dinosaur King]

So this means that T Rex could of shed its feathers as it grew up or to adapt to a climate. That was an old theory that was disproved because scales supposedly couldn't exist under feathers. This find opens up so many possibilities for therapods. Having scales and feathers both would make them very adaptive to changing climates or extreme seasons.

I never thought of this before, a very good theory.

[Papi-Anon]

After reading that all I could think of was how Anchiornis wings would've tasted... 

See, this was where John Hammond truly failed. Jurassic Park should have been Jurassic Farm: a wondrous place where the mighty (non-avian) dinosaurs that once ruled the Earth are now another tasty meal for the current dominant species of the planet.

Think of the menu!

Tyranno-steak!
Brachio-burgers!
Buffalo-style Velociraptor!
Dilophosaurus 'Spit Pea' Soup!
Compy-nuggets for the kids' Hatchlings Menu!

[stargatedalek]

So this means that T Rex could of shed its feathers as it grew up or to adapt to a climate. That was an old theory that was disproved because scales supposedly couldn't exist under feathers. This find opens up so many possibilities for therapods. Having scales and feathers both would make them very adaptive to changing climates or extreme seasons.

No it doesn't. Not at all. This only proves that Anchiornis had the same pattern of feathers growing over top of scales as many modern birds do. This in no way suggests the pattern presents the adaptive benefits of both (if it did birds would be entirely covered in it), and it certainly doesn't suggest rapid changes in integument via climate let alone age.

So this means that T Rex could of shed its feathers as it grew up or to adapt to a climate. That was an old theory that was disproved because scales supposedly couldn't exist under feathers. This find opens up so many possibilities for therapods. Having scales and feathers both would make them very adaptive to changing climates or extreme seasons.

I never thought of this before, a very good theory.

It's not a theory, it's an internet myth spread by people who won't let the past die.

The preserved impressions of Tyrannosaurus aren't even solidly identified, they might be skin or scales, and they are absolutely not analogues to the scales on bird feet regardless.

[Dinoguy2]

So this means that T Rex could of shed its feathers as it grew up or to adapt to a climate. That was an old theory that was disproved because scales supposedly couldn't exist under feathers. This find opens up so many possibilities for therapods. Having scales and feathers both would make them very adaptive to changing climates or extreme seasons.

No it doesn't. Not at all. This only proves that Anchiornis had the same pattern of feathers growing over top of scales as many modern birds do. This in no way suggests the pattern presents the adaptive benefits of both (if it did birds would be entirely covered in it), and it certainly doesn't suggest rapid changes in integument via climate let alone age.

I dunno, as others have already mentioned, the feet of Anchiornis most resemble the patterns seen in ptarmigans - and that's exactly what ptarmigans do. There's no reason to think T. rex, of all species, would have seasonally shed its feathers, but I don't think there's anything about it that's implausible.

You're right that in modern birds, this pattern only exists on the feet, which are default scaly. But in Anchiornis we already know there were scales under the leg feathers. And in modern birds, the body feathers are important for flight, so seriously altering or reducing them would be very maladaptive. In a primarily flightless species covered in simpler feathers rather than contour feathers, who knows.

Another internet myth is that there is a one-size-fits-all answer to the question of which dinosaurs were feathered. There's so much diversity and pure weirdness going on with dinosaur integument these days that literally nothing would surprise me anymore. Which makes sense, since dinosaurs are such a massive, diverse group it hardly even makes sense to say anything that applies to all of them equally. http://dinogoss.blogspot.com/2013/03/who-cares-about-dinosaurs.html

[stargatedalek]

Ptarmigans are only one example of birds with this pattern of leg feathering, and are doing something entirely different from what say owls are (they use them as sensory organs). If the implication was climate adaptation tropical and sub-tropical owls wouldn't display this same trait, insulation is just one of many potential applications. To suggest that this is evidence of similar seasonal loss in plumage over the entire body in non-avian dinosaurs is problematic primarily because it only takes into account one potential explanation, but also because it's extremely close to the standard anti-feather rhetoric. I don't take issue with the idea something akin to ptarmigans may have occurred, but I take serious issue with it being claimed as solid evidence, let alone in favour of an entire animal balding seasonally.

Legs are a far-cry from an animals entire body, chickens for example will display this same form of feathering through scales on their legs in certain breeds. And yet in contrast ratites display a lot less scales than flying birds do, even those with large patches of exposed skin like ostriches. So clearly this doesn't present an objective advantage for an animal. Scales on the legs of most birds serve a primarily defensive role, whether against the elements or the terrain. Ptarmigans are still climbing and running about over rough terrain a lot of the year, so they need those scales, whereas most ratites don't have as much use for them since they don't climb and most don't live in forests (and those that do retain these scales for the most part). Therefore it's highly unlikely an animal would ever develop these scales across the entirety of its body.

It's not entirely implausible that Anchiornis was doing something similar to ptarmigans, but it is implausible to claim this is evidence of a similar adaptation in any animal that doesn't display these same "avian scales". We only have evidence of this trait occurring alongside this very specific form of scales, which we know Tyrannosaurus did not have (at least not on the majority of its body).

[Neosodon]

Stargatedalek, I think you are trying to over simplify things be assuming T Rex had the same anatomy as birds. There is no bird that has scales on its tail. And we no T Rex did. Anchiornis was more closely related to T Rex than any modern bird. If feathers can grow on scales on one portion of the body then its possible they can do it anywhere.

Saying that T Rex could NOT have a full coating of scales and feathers and the ability to shed them because no modern bird has that trait is like saying T Rex must of clucked like a chicken because no modern bird can roar.

I know it is just a theory and there is no hard evidence for it but saying it is an internet myth because because it does not fit your assumptions on dinosaur anatomy is taking your opinion to far.

[stargatedalek]

stargatedalek, I think you are trying to over simplify things be assuming T Rex had the same anatomy as birds. There is no bird that has scales on its tail. And we no T Rex did. Anchiornis was more closely related to T Rex than any modern bird. If feathers can grow on scales on one portion of the body then its possible they can do it anywhere.

Saying that T Rex could NOT have a full coating of scales and feathers and the ability to shed them because no modern bird has that trait is like saying T Rex must of clucked like a chicken because no modern bird can roar.

I know it is just a theory and there is no hard evidence for it but saying it is an internet myth because because it does not fit your assumptions on dinosaur anatomy is taking your opinion to far.

All of that is incorrect, and provably so.

There is NO CERTAINTY on what the Tyrannosaurus impressions are. No one knows if these are scales or skin.

Anchiornis is closer to modern birds than it is to Tyrannosaurus. So I really don't understand why that makes any difference.

I didn't say it couldn't, I said this wasn't evidence in favour of that. And IT ISN'T. You aren't reading what I've said. This trait has only been found to occur with a very specific form of scales which are only known from the feet of birds and close relatives. There is absolutely no evidence to indicate this trait occurred with other forms of scales.

Only large cats can roar, so no Tyrannosaurus didn't roar. It may have made very loud sounds, but it didn't roar.

The concept that Tyrannosaurus lost feathers as it aged is an internet myth. It's been circulating since people first suggested Tyrannosaurus had feathers and some people in deep denial came up with the silly notion it may have lost them with age so they could hold onto their precious image of the scaled tyrant.