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The Terrible Claw by EWilloughby The Terrible Claw by EWilloughby
Diagnostic anatomical reconstruction of Deinonychus antirrhopus, intended loosely for Wikipedia but also as an experimental piece to show pretty much exactly how I believe this animal looked in life.

This was largely inspired by an interesting Facebook discussion with paleoartist Julius Csotonyi about arm-folding in paravian dinosaurs. It occurred to me that people seldom reconstruct paravians, particularly dromaeosaurs, with their arms folded in a reasonable and accurate way. Julius made the fair point that these animals probably didn't carry their arms out in front of the body, as is so often depicted (in skeletals and otherwise — it makes sense in skeletals, to adequately show the hand and arm anatomy), because such an awkward orientation would leave the hand and arm feathers open to damage and breakage. But they also can't fold them tightly against the breast or back like birds do, because they lack the mobility to do so.

So how did Deinonychus normally carry its arms? Senter's 2006 paper on forelimb function in Deinonychus and Bambiraptor shows that the humerus couldn't rotate much past the horizontal with respect to the scapula. In addition, Sullivan et al. 2010 — winningly translated to layman coherency by Matt Martyniuk — shows that wrist mobility in many paravians is much less than you might expect, given their similarity to birds. The wrist of Deinonychus antirrhopus specifically would not have allowed it to bend its hands even 90° with respect to the arm!

Given these limitations, most of the flexion would have to occur at the elbow, but a fully flexed elbow would mean that the hands would be hanging below the body, not held sleek and secure alongside the body. The arm orientation in my illustration above is based on what I think is probably the perfect configuration for carrying the arms: a fully-flexed shoulder, a fully-flexed wrist, and a nearly fully-extended elbow. A few other people have drawn their dromaeosaurs with the same arm configuration, like Smnt2000 and pilsator, so kudos to them. 

Illustration based on the papers linked above as well as ScottHartman's beautiful skeletal. Gouache on 12" x 20" hot-pressed illustration board. 
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:iconwinterwantsmoon:
WinterWantsMoon Featured By Owner 4 days ago  Hobbyist
love this art. prefer this over JP raptors anyday!
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:iconwestseax:
WestSeax Featured By Owner Dec 30, 2018
I'm rather skeptical of the idea that holding the arm out in front of the animal would lead the arms and feathers being damaged and broken. If you've ever seen chicken run they hold out their wings for balance and even flap them to get a boost. Parrots will often also hold their wings out while climbing, ready to flap in case they lose their balance. I've owned lovebirds and they often beat their feathers off the bars of the cage and their perches while climbing or hopping but it doesn't seem to bother them. I personally tend to imagine that these critters held them out below them, maybe spread a little (to the extent they could spread them), for balance and ready to snatch up prey.
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:iconseemycriitersss:
seemycriitersss Featured By Owner Sep 15, 2017
So why are chickens the only birds people like to compared dinosaurs to?
would that be like comparing a house cat to a saber tooth cat?
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:iconacepredator:
acepredator Featured By Owner Oct 7, 2018
It would be like comparing a mouse to a Sabretooth.
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:iconbatterymaster:
Batterymaster Featured By Owner Jan 20, 2018  Student General Artist
Because its an excuse for BANDits to ridicule feathered dinosaurs, that's why.
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:iconwinterwantsmoon:
WinterWantsMoon Featured By Owner 4 days ago  Hobbyist
yes. there is no need for the hate feathered dinosaurs get. It's like everyone wants the Jurassic park raptors back and dismisses almost fact on how the animals looked like. 
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:iconwilliam023:
william023 Featured By Owner Apr 4, 2017
I hated seeing raptors running about with arms out in front, it always looked silly because it would slow them down and yes, in enclosed spaces, it'd damage their wings, but it also just made them look awkward because they weren't streamlined, I prefer this sleeker stance. I mean, they obviously outstretched their wings when balancing on bigger prey, fighting each other, maybe when hugging(don't laugh, some birds really do wrap wings around each other), for warming eggs and chicks, or just threatening opponents. But the world needs more streamlined dromeosaurs.
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:iconzappyzor:
zappyzor Featured By Owner Apr 16, 2016  Student Digital Artist
I love this picture
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:icondovahsaurpaleoknight:
AWSOME!
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:iconviktorarnason:
ViktorArnason Featured By Owner Mar 17, 2016
hi TREY sent me
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:iconmilenajure:
MilenaJure Featured By Owner Dec 5, 2015  Hobbyist
is it Deinonychus? i love it
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:iconchinmoy808:
chinmoy808 Featured By Owner Dec 15, 2015  Hobbyist Traditional Artist
it is
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:iconcreature218:
Creature218 Featured By Owner Aug 15, 2015
I just got an idea for Jurassic park 5  they find more complete dinosaur dna and have the feathered dinosaurs fight the non feathered ones, P.S. most amazing dinosaur art I have ever seen
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:iconacepredator:
acepredator Featured By Owner Nov 7, 2015
I've been thinking that for a long time...and an accurate Spinosaurus drowns the JP version.
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:iconwinterwantsmoon:
WinterWantsMoon Featured By Owner 4 days ago  Hobbyist
funny, epic, but sad. 
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:iconjustarandomgourgeist:
JustaRandomGourgeist Featured By Owner Dec 27, 2016  Hobbyist Digital Artist
That would be both epic and funny to see
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:iconcreature218:
Creature218 Featured By Owner Nov 7, 2015
Exactly
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:iconimperator-201:
Imperator-201 Featured By Owner Oct 10, 2015
Yessss, that's my idea exactly! And I say this because in the film Jurassic World a character says that the dinosaurs would look different if they had 100% pure DNA.
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:iconbaryminer:
BaryMiner Featured By Owner Jul 26, 2015  Student Traditional Artist
I applaud you for having the most accurate raptors I have EVER seen! Clap 
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:icongrisador:
grisador Featured By Owner Jul 3, 2015
Does it capable of using its hand/claws ? :O
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:iconewilloughby:
EWilloughby Featured By Owner Jul 3, 2015  Professional General Artist
There is surprisingly little evidence to suggest that dromaeosaurs, despite the robust hand-claws, were using their hands in predation at all. Some researchers have suggested that the main function of handclaws may have been to support a partially arboreal lifestyle, at least in juveniles. The function of handclaws in dromaeosaurs is still an open question, as far as I'm concerned. 

That said, there is no reason to assume that large hand and arm feathers would preclude mobility and grasping ability in dromaeosaur hands. The Senter paper linked in the description covered this quite nicely, and here's my take on it.
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:icongrisador:
grisador Featured By Owner Jul 6, 2015
Thanks a Lot for the answer & the Link !

I see. İts still an unclear subject; But the grasping\catching ability seems very Possible
Its also possible to Raptor's use their proto-wings and claws at their infancy
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:iconterizinosaurus:
Terizinosaurus Featured By Owner Jun 18, 2015
IT IS GOOD:D (Big Grin) 
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:iconsinovenatorchangii:
SinovenatorChangii Featured By Owner May 17, 2015
Very bird-like.Amazing+fav 
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:iconcs12700:
Cs12700 Featured By Owner Apr 29, 2015  Hobbyist Traditional Artist
How long does it usually take for you to finish your artwork? (Awesome btw)
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:iconpachyornis:
Pachyornis Featured By Owner Mar 21, 2015  Hobbyist
I love your Deinonychosaurs, they are gorgeous!
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:icondinu1999:
dinu1999 Featured By Owner Mar 1, 2015  Hobbyist Digital Artist
Love it! :)
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:iconi-phillip:
I-Phillip Featured By Owner Feb 24, 2015
This is the level of skill I hope to one day acquire, any tips on how to paint feathers so stunningly?
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:iconewilloughby:
EWilloughby Featured By Owner Mar 8, 2015  Professional General Artist
Thank you! It's taken me a while to get to this point with my work, and I still have a very long way to go. One thing I can suggest is pay attention to how the light would be attending to each individual feather: feathers are individual objects, not a single flat plane, which means that each feather would have its own breadth of light and shadow. For especially thick and large feathers, they'll cast a noticeable shadow on the feather below it. That's how I've done the wing feathers here, though the body feathers could use some improvement in this respect. My Zanabazar is a better example of the "each feather casts its own shadow" concept. 
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:iconi-phillip:
I-Phillip Featured By Owner Mar 8, 2015
Thank you so much for the response! You're a terrific artist and I can't wait to put your advice to use. 
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:iconpaleohyperspace:
Paleohyperspace Featured By Owner Dec 14, 2014  Hobbyist General Artist
I can't believe that I never added this one to my favorites! Now that I own the original, I can't very well justify not doing so. Sorry for neglecting to do so several months ago!
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:icondennonyx:
Dennonyx Featured By Owner Dec 1, 2014   Traditional Artist
Terrible claw, beautiful bird. :heart:
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:iconmr--jack:
Mr--Jack Featured By Owner Oct 16, 2014  Professional
Such a beautiful rendition :D
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:iconperfectchaos22:
PerfectChaos22 Featured By Owner Edited Aug 30, 2014  Hobbyist Artist
Wouldn't it look more furry than feathery, since proto feathers were more like fur
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:iconithinkofanamelater:
IThinkOfaNameLater Featured By Owner Oct 5, 2016
Nope. Dromaeosaurs Had stage 4 feathers.
 
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:iconperfectchaos22:
PerfectChaos22 Featured By Owner Oct 5, 2016  Hobbyist Artist
Oh, I always get those mixed up, so what dinosaurs had protofeathers?
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:iconithinkofanamelater:
good examples are Sciurumimus albersdoerferi , and on Sinosauropteryx. What you would call protofeathers are stage 1 and 2. I would read this.  emilywilloughby.com/gallery/sk…   
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:iconewilloughby:
EWilloughby Featured By Owner Edited Aug 30, 2014  Professional General Artist
Related dromaeosaurs have been found with fairly well-developed vaned feathers, so it's definitely within the realm of conservative speculation to depict Deinonychus with similarly advanced feathers. www.deviantart.com/art/Feather… Stage 1 and 2 feathers would definitely look more furry than feathery, but examples of feathers at that stage of evolution lie far outside Deinonychosauria in much more basal clades. When I hear "protofeather" I think of animals like Sinosauropteryx, but whatever Deinonychus had definitely wouldn't be quite the same.
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:iconorange-eyed-serpent:
orange-eyed-serpent Featured By Owner Oct 14, 2014  Hobbyist General Artist
Actually...

I found a really fascinating article awhile back, citing a paper by Chen and Currie (2001), that the feathers of Sinosauropteryx *might* be at least stage 3, due to the fact that there's strands that are at an angle to a central, rachis-like thick strand. Here's where I read about that:
dinogoss.blogspot.com/2012/08/…

If this is true, this would definitely be pretty groundbreaking....but sadly, it doesn't look like anyone's bothered to examine Sinosauropteryx's feathers in much more detail since them, and taphonomy is always an issue... (Unless someone has examined it again and I'm not aware of it.) I guess we're right to be cautious unless something more convincing is produced, but this has already sort of convinced me. :P

If their conclusion is true...what do you think of the possibility that more advanced feathers were selected for in these non- avialan groups by not flight, but insulation and/ or display? After all, might blue be possible in a Stage 3 feather? Maybe not, since I recall you saying it needed to have the small air pockets that flight feathers have...

I can't help but wonder about these things. Been wanting to ask you about that for a while, so I figured this thread was the perfect place to voice it. :P
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:iconagahnim:
Agahnim Featured By Owner Oct 15, 2014
Yeah, I remember discussing this with Matt about two years ago.  He described the feathers on Sinosauropteryx as "stage 2.5".  Most papers describe them as stage 2, though.  (And sometimes even as stage 1, even though that's clearly inaccurate.)

I think it's very likely that more advanced stages of feathers evolved for reasons unrelated to flight.  Stage 4 feathers are found on Caudipteryx, which almost definitely didn't have a flying ancestor, so display is the most likely reason it had them.
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:iconorange-eyed-serpent:
orange-eyed-serpent Featured By Owner Oct 16, 2014  Hobbyist General Artist
Oh, that's interesting. Yeah, maybe the feathers on Sinosauropteryx are a sort of intermediate between stage 2 and 3...

Yes, that's very true about Caudipteryx. Justin says that Greg Paul believes oviraptorids to be descended from a flying ancestor though, if I remember right. I don't necessarily agree with that, though. I don't know much about oviraptorids, but I didn't think they had as many characteristics related to flight as deinonychosaurs...aside from (obviously) the Stage 4 feathers, and the pygostyle-like structure on the ends of some of their tails, which isn't found in any dromaeosaur that I know of.
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:icontkwth:
TKWTH Featured By Owner Aug 17, 2014  Hobbyist Digital Artist
Most definitely the best D. antirrhopus restoration I think I've ever seen. Kudos to you. :)
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:iconblahart112:
blahart112 Featured By Owner Aug 12, 2014
Why did I think this was a dinosaur?
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:iconblahart112:
blahart112 Featured By Owner Aug 12, 2014
Oops didn't read the description, sorry!! It is a dinosaur!!
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:iconewilloughby:
EWilloughby Featured By Owner Aug 12, 2014  Professional General Artist
It is a dinosaur (this one, to be precise). Is there some confusion about it?
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:iconsilenced-dreams:
Silenced-Dreams Featured By Owner Aug 10, 2014  Hobbyist Traditional Artist
just keep inspiring me to someday make more paintings, why don'tcha!

Love how you handle gouache and manage to keep it looking all birdy-dynamic.
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:iconstudiospectre:
StudioSpectre Featured By Owner Aug 9, 2014  Professional General Artist
I know that wing feathers are well established in Archaeopteryx and so many Maniraptorans and other Dinosaurs/birds. 
I know it's inferred for Dromeaosaurs, but is there any direct evidence in the form of impressions or any other fibers bound near the arms of Dromeaosaurs?
I'm with you that it's a certainty that they were heavily feathered, but with what kinds?
It would seem to me that big floppy feathers (true, or close to true modern feathers) on the wings would perhaps get in the way of grabbing prey or using the forelimbs as weapons. The large Dromeaosaurs definitely didn't fly or glide, but at the same time, the smaller dinosaurs/birds from the mesozoic that we have definite evidence for flight/wing type feathers on the arms were certainly using their arms to catch prey with, much like we would assume the Dromeaosaurs were doing. So I guess flight feathers were possibly not an issue in catching prey and may have had other reasons for being present such as Aerodynamics, display, heating/cooling. 
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:iconchinmoy808:
chinmoy808 Featured By Owner Edited Oct 31, 2015  Hobbyist Traditional Artist
For that question, there are quill knobs on velociraptor and the newly discovered dakotaraptor, and zhenyuanglong has those impressions, as well as sinornithosaurus and microraptor. Geez, creationists and jp fanboys must hate china right now.
Reply
:iconstudiospectre:
StudioSpectre Featured By Owner Nov 1, 2015  Professional General Artist
well, why would they hate China? it's not as if the nation has any responsibility for the new discoveries we have. 
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:iconstudiospectre:
StudioSpectre Featured By Owner Nov 11, 2015  Professional General Artist
No, I honestly don't think much about the stupid people of the world, and rather concentrate on smart folks. I do see what you mean now though. 
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