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Late Cretaceous  stembird by ScottHartman Late Cretaceous  stembird by ScottHartman
Complete overhaul today! The very complete (for an avisaurid) specimen I used to produce the older version was published today as Mirarce eatoni: peerj.com/articles/5910.pdf

Enjoy having a semi-reasonable idea of what avisaurids looked like now.
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:icontyrannosaur19:
Tyrannosaur19 Featured By Owner Nov 14, 2018  Hobbyist Traditional Artist
I really like this One! 
What i find very interesting is that some of Its characteristics are surprisingly dinosaurian, avisaurids feel like the perfect transitional forms between ancient more dinosaur/reptile-like birds and more modern and flight-specialized birds. 
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:iconscotthartman:
ScottHartman Featured By Owner Nov 24, 2018  Professional Digital Artist
I agree. That's why I strongly oppose the use of the word "bird" (unless it's part of "stem-bird") for anything below the avian crown group - it covers up all the wonderful and amazing diversity of forms between basal avialans and true crown birds as we know them.
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:icontyrannosaur19:
Tyrannosaur19 Featured By Owner Nov 25, 2018  Hobbyist Traditional Artist
So, how would you classify Archaeopteryx? Is it a bird like dinosaur? Or a dinosaur-like “stem-bird”? i’m more inclined towards the first option. 
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:iconscotthartman:
ScottHartman Featured By Owner Nov 26, 2018  Professional Digital Artist
I don't like "dinosaur-like" because they are all exactly like dinosaurs. Bird-like dinosaur is fine by me. "Basal avialan" is more precise if you're talking to a fellow dinosaur-nerd.
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:icontyrannosaur19:
Tyrannosaur19 Featured By Owner Nov 26, 2018  Hobbyist Traditional Artist
Well, yes, I stand corrected, as my terminology was a bit off, By dinosaur-like I meant reptile-like, which I think suits most large dinosaurs.
Basal Avialan May be a better term, but I think “bird-like dinosaur” pretty much describes all basal avialans, basically. 
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:iconmattmart:
MattMart Featured By Owner Edited Nov 26, 2018  Hobbyist Digital Artist
I wouldn't say "dinosaur-like" because it IS a dinosaur... "bird-like dinosaur" is good. You could say all ornithodirans are "bird-like reptiles".
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:icontyrannosaur19:
Tyrannosaur19 Featured By Owner Nov 26, 2018  Hobbyist Traditional Artist
Yes, basically. 
But, my term was referring more to “reptile-like” bird instead of “dinosaur-like” bird, which I think is more appropriate wording, still, my mistake. 
Basal avialans were certainly bird-like dinosaurs though. 
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:iconpaleoartbymcgowan:
PaleoartByMcGowan Featured By Owner Nov 14, 2018  Professional General Artist
Does this also actually tell us about the ecology or niche that Avisaurids occupied in life?  I recall from s a source several years ago that Avisaurids were considered analogues to modern raptors.  Does this new specimen refute or confirm that hypothesis?
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:iconscotthartman:
ScottHartman Featured By Owner Nov 24, 2018  Professional Digital Artist
I don't think it can speak strongly to dietary niche, unfortunately. We'll need even more amazing specimens for that.
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:iconpedrosalas:
PedroSalas Featured By Owner Nov 14, 2018  Professional Traditional Artist
I can see it walking like a crow.
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:icondeinocheirusmaster:
deinocheirusmaster Featured By Owner Nov 13, 2018  Hobbyist Traditional Artist
How come this one has no teeth like the other enantiornithines?
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:iconscotthartman:
ScottHartman Featured By Owner Nov 13, 2018  Professional Digital Artist
The author's feel that most of the Late Cretaceous enantiornithines lost their teeth. Obviously there is no skull for any avisaurid, so this is just an inference.
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:icondeinocheirusmaster:
deinocheirusmaster Featured By Owner Nov 14, 2018  Hobbyist Traditional Artist
I always thought that all enantiornithines had teeth. Great skeletal by the way! 
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:iconmattmart:
MattMart Featured By Owner Nov 26, 2018  Hobbyist Digital Artist
Unless I'm mistaken, gobipterygids are the only known toothless enantiornithines (and they have pointy, Confuciusornis-like beaks).
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:icondeinocheirusmaster:
deinocheirusmaster Featured By Owner Nov 26, 2018  Hobbyist Traditional Artist
Thats very interesting to hear!
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:iconeriorguez:
Eriorguez Featured By Owner Nov 14, 2018
Wouldn't a more reasonable inference be using phylogenetic bracketing? Not keen on how stuff published by O'Connor seems to rely more and more on gut feelings and arguments from authority...

It is true that we lack Avisaurian skulls, but, come on, this is a bit of an extraordinary claim to make.
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:iconscotthartman:
ScottHartman Featured By Owner Nov 15, 2018  Professional Digital Artist
I definitely wouldn't consider it an open and shut case.
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:iconeriorguez:
Eriorguez Featured By Owner Nov 15, 2018
In any case, it is always good to see more Avisaurian material, and here is hoping we get some cranial elements in the near future.
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:iconmesozoic0906:
Mesozoic0906 Featured By Owner Nov 13, 2018
What would be likely niche of this animal? I used to think Avisaur as something like Cretaceous bird of prey, but lack of teeth took me by surprise.
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:icondeform2018:
Deform2018 Featured By Owner Nov 13, 2018  Student Traditional Artist
At Last! A new skeletal, GG Scott!
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:iconscotthartman:
ScottHartman Featured By Owner Nov 13, 2018  Professional Digital Artist
So many new skeletals...sorry most of them are under embargo!
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:iconalbertonykus:
Albertonykus Featured By Owner Nov 13, 2018
I take it that the unpublished elements of this became Mirarce!
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:iconscotthartman:
ScottHartman Featured By Owner Nov 13, 2018  Professional Digital Artist
You take it correctly!
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:iconmark0731:
mark0731 Featured By Owner Sep 14, 2018
It's an avian?
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:iconscotthartman:
ScottHartman Featured By Owner Nov 13, 2018  Professional Digital Artist
It's not part of crown birds (Aves by most people's definition), but it's an enantiornithine, a group of stem birds that clearly were capable fliers.
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:icondinopithecus:
Dinopithecus Featured By Owner Nov 14, 2018
Would you happen to know if Archaeopteryx is still what we'd deem a crown bird (I guess I'm one of those people who define that as Aves)? Or is it just an avialan preceding birds proper? Wikipedia appears to suggest the latter, and so I was wondering if that's correct.
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:iconscotthartman:
ScottHartman Featured By Owner Nov 15, 2018  Professional Digital Artist
A crown clade is the most recent common ancestor of all living species (and all descendants of that ancestor). Archaeopteryx is very, very far away from the crown clade. In fact, it's usually one of the most basal avialans found, and sometimes it's not even found as an avialan (though those findings are so far in the minority). Basically, Archaeopteryx is not very bird-like at all. Mirarce (and other enantiornithines) are significantly closer to crown birds than Archaeopteryx, but still quite a ways away.

One reason I oppose the use of the "bird" in the vernacular for things like Archaeopteryx or even enantiornithines is that it tends to hide how amazingly diverse non-avian avialans actually were in the Cretaceous.
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:iconsinusonasus1:
sinusonasus1 Featured By Owner Jul 16, 2016  Student Photographer
Were Avisaurs good walkers? in Mr. Martyniuk's field guide it said they were specialized perching birds, and it looks more lifelike that way. I think they would have walked more like crows with their backs oriented more diagonally. 
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:iconscotthartman:
ScottHartman Featured By Owner Jul 20, 2016  Professional Digital Artist
Avisaurs do seem like better perching birds. I'm less sure about the tilted body posture being habitual at this stage, but any theropod could tilt their bodies up to an angle of ~15-20 degrees if they wanted to.
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:iconatlantis536:
Atlantis536 Featured By Owner Jul 15, 2016  Hobbyist Traditional Artist
I call it "Angela". Do you like the name?
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:iconscotthartman:
ScottHartman Featured By Owner Jul 25, 2016  Professional Digital Artist
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:iconpedrosalas:
PedroSalas Featured By Owner May 2, 2014  Professional Traditional Artist
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:iconeriorguez:
Eriorguez Featured By Owner Nov 19, 2013
May I ask your opinion on the idea of those animals being a sort of enant birds of prey, so to speak?
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:iconalgoroth:
Algoroth Featured By Owner Aug 23, 2013  Professional General Artist
This...is flat out weird. Nice art, as usual, but I have a hard time seeing this working as a living adult. Is it supposed to be a juvenile? Or were enantiornothines just strange this way?
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:icondinobirdman:
DinoBirdMan Featured By Owner Jun 12, 2013  Student Artist
This is main good for this paleo-bird.:)
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:iconzippo4k:
Zippo4k Featured By Owner Jun 12, 2013
What a bizarre animal. It's legs are so short. I'd sort of expect it to walk with the body tilted upright like a loon, but on the other hand, it's legs aren't as far back as a loons, at least I think... O_O
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:iconpfunkei:
Pfunkei Featured By Owner Mar 28, 2014
Maybe it walked like the archaic depictions of dinosaurs?
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:iconpeteridish:
PeteriDish Featured By Owner Jun 12, 2013  Hobbyist General Artist
i bet it tasted like chicken! XD
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:iconscotthartman:
ScottHartman Featured By Owner Jun 12, 2013  Professional Digital Artist
I bet you're right!
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:iconpeteridish:
PeteriDish Featured By Owner Jun 12, 2013  Hobbyist General Artist
:lol:
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:iconvasix:
vasix Featured By Owner Nov 20, 2011  Hobbyist Digital Artist
What are the dimensions of Avisaurus then?
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:iconscotthartman:
ScottHartman Featured By Owner Nov 21, 2011  Professional Digital Artist
Eh, big crow-sized?
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:iconvasix:
vasix Featured By Owner Nov 25, 2011  Hobbyist Digital Artist
Not too big, that thing....flier? Or weak?
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:icondesmodeus:
Desmodeus Featured By Owner Jun 12, 2013  Hobbyist Traditional Artist
Looking at the size of its breast bone, I'd personally be very surprised if it could fly
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:iconscotthartman:
ScottHartman Featured By Owner Jun 12, 2013  Professional Digital Artist
Enantiornithines at this stage are presumed to fly. How well is fair question IMO.
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:icondesmodeus:
Desmodeus Featured By Owner Jun 13, 2013  Hobbyist Traditional Artist
Huh... Needs much less muscle power than I would have imagined, personally. O_o
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:iconscotthartman:
ScottHartman Featured By Owner Nov 15, 2018  Professional Digital Artist
Man am I ever late replying to this, but assuming enantiornithines didn't fly for long periods of time (e.g. they were just flapping around forests, and not migrating seasonally) then they could fly just as well for short periods having more fast-twitch than slow-twitch muscle fibers (i.e. they'd have more white meat than dark meat in the pectoral muscles). Part of the giant expansion of the flight muscles leading towards crown birds is they also increase their ability to breath while they fly - those improvements result in them being able to utilize aerobic respiration more or less indefinitely during flight, but also requires a shift to more slow-twitch muscles (that can take advantage of the constant supply of oxygen), and slow-twitch muscles are weaker pound for pound compared to fast-twitch muscles, so you need more of it.
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:icondesmodeus:
Desmodeus Featured By Owner Dec 4, 2018  Hobbyist Traditional Artist
It seems like such a glaring issue now that you say this, but I've never really considered the balance of fast- to slow-twitch muscle fibers in anything other than MMA fighters. Very interesting.
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(1 Reply)
:iconjohnfaa:
JohnFaa Featured By Owner Jan 29, 2011  Student Writer
I'm not sure about the toothed jaws, as someone has suggested that Avisauridae is close to Gobipteryx, which is known to be toothless
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:iconscotthartman:
ScottHartman Featured By Owner Jan 29, 2011  Professional Digital Artist
It's possible. Enantiornithine phylogeny is still in flux though, and Gobipteryx has a pretty autapomorphic skull, so I wasn't going to follow suit at this point. Still, I may have to revisit the skull in the future pending additional finds.
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