Why Dinos (apart from having feathers)..

... are weirder than you CAN imagine ...

XKCD tip from artist John Conway's Twitter feed.

Darren's Opinion of Feathered Dinos...

Darren's opinion on feathered dinos is at LEAST as strong as mine, and better informed-- but I didn't do a T- Shirt. I don't usually wear one, but I have ordered his, in a kind of dayglo golden orange at that...

Darren's blog(s)-- his has had several versions and sponsors-- have been what I thought of as my siblings, though his have always seemed more specifically "naturalist" in subject than mine. We have both been writing blogs for about ten years-- he has theoretically fewer posts, though I would say far more substantial ones-- I do a lot of light stuff, not to mention Magdalena and NM rural views. But we started linking, and talking about those great predators, Golden eagles, in his first post. This led to his appearance in my Eternity of Eagles ,  and mine in his first Tet Zoo collection.

I think the common subjects extend far further than a non- scientist, or perhaps a non- artist, might assume-- ask my friend Carlos Martinez del Rio, who runs the Berry Center for Biodiversity at the University of Wyoming in Laramie (unfortunately,  often confused in the popular mind with the godawful Southwest Biodiversity Center down here, which mostly sues ranchers and puts them out of business (it is an open secret in the Southwest that one of the biggest real estate developers  down here is a big supporter, picking up the deeded private portions of the ranches when the Center gets them thrown off their public land leases). There is an unwritten book about one of the best arguments for public land ranching, AKA "welfare ranching" in certain circles. The deeded land is riparian and private; the leases are the dry uplands. Once the ranchers lose the leases, they must sell the home place, which usually has the springs and such, to developers, which as far as I can see DECREASES biodiversity. That it was founded by a failed graduate student in literature at Stony Brook, with a penchant for literary "theory", rather than a naturalist or conservation biologist, is adequately documented in this story in the New Yorker, where you get the distinct impression that the writer went in as a fan and changed his mind.

Whereas the Center at Laramie, founded by a wealthy heir to a Main Line Philadelphia fortune who was also one of the four founders of the Peregrine Fund, exists only to study, promote, and celebrate the earth's creatures in all their splendid diversity.

More soon-- lots more to unpack here. But read Darren!

Early update: I would say these nice little figures of a Velociraptor mongoliensis and an Oviraptorid are nice, but not "birdy" enough-- they are still "feathered lizards".

 

This might be more like it:

Watch for my swan song in the next Living Bird, my last scheduled assignment, called "They had FEATHERS!"

Update on "Beebesaurus"

... also known as Microraptor gui. I painted it a sort of irridescent black, to conform with what is known about its feathers. Can't believe how much it looks like Beebe's bookplate in his pre- WW I (1910) book Our Search for a Wilderness. Microraptor was dug up in China in 2003.

Raptor vs Rex

Moro Rogers has a delightful new serial webcomic, featuring the adventures of a (properly feathered) "Raptor"*.

* Mark Witton will explain why "Raptor" is a dumb common term for Dromaeosaurs. Not Moro's fault-- she knows Dinos-- just pop culture's.

Paradigm SHIFTED

... decisively: not the "Cover of the Rolling Stone" as I have been calling it but, of course, that of Scientific American. I thought at first they were a bit late to the party, as it was the late John Ostrom who started the ball rolling with his discovery of Deinonychus, which he reported in SA in an article which suggested warm bloodedness but did not QUITE say feathers. That must have been (a lot?) more than thirty years ago. Robert Bakker soon called T rex the "20,000 pound Roadrunner from Hell", but as far as I can see it was my old friend John McLoughlin who first dressed raptors in feathers in the popular press-- 1979? I'm sure he'll tell me.

Now proud Tyrannosaurs have them, in mainstream publications. On second thought, SA deserves great credit. It may be slow compared to the avant garde, but it is the FIRST popular magazine to portray a feathered tyrant, as well as the first to broach the ideas that led to it.

Two more thoughts. I counted only four sentences in- text that said "feather"-- after paradigms shift, they seem "normal".

Second, what do readers think about those poor naked chickens coming in the new Jurassic Park thing? And what about the less sophisticated public?

Paradigm Shift!

It's happening  NOW. Tim Gallagher just sent me this image from a comics website: feathered tyrannosaurid attacking Roman legionnaires!

Feathers

Bird and Moon knows "raptors" have feathers...

(HT Annie Davidson).

 

Apparently, Stephen Spielberg does not.

 

If you prefer featherless Dinos...

... like those in Jurassic Park, you might also think chickens look like this:

"Washington and Moscow"

In 1983,  artist and evolutionary biologist John Mcloughlin was so sure of feathered Dinos that, in his novel The Helix and the Sword,  he gave the role of  the pets and executioners of his  post -Apocalyptic  Asteroid Belt civilization's cruel "Regent" to a pair of eagle- like, genetically re- created Deinonychids, with feathers like Golden eagles, and named them after the legendary destroyers of planetary civilization: Washington and Moscow.

It has taken more than thirty years for an artist to produce a version of this wonderful... I almost put "beast", but that is a mammal word-- creature; bird; whatever,  worthy of his vivid  and prescient re- creation. Here it is, with a quote from the hermit of Talpa.

"Man- high, smooth- coated in short blackly irridescent feathers, red of eye and each wearing a diamond- studded Regency orange collar, Washington and Moscow were delivered to Lothar IV by the Sisterhood. Thenceforth, they accompanied  Lothar IV everywhere he went, standing outside his chambers when he slept, beside him when he ate. They were his trademarks, and his joys, and the agents of his Regental wrath as well..."

Links, Big Birds, and all the news that fits...

When you have been dealing with meds and other unavoidable and  annoying facts of aging, everything piles up. You don't think Lucas Machias or Lane B stops mailing or that Annie D doesn't send me a mix of the surreal and the biological, or JP stops writing his serious essays, do you? The world goes "whirling still"*, and all the news is not Ebola or Isis (though they are as close to where I spent time in Kurdish Turkey as I am to Socorro-- thirty miles!)

News per se is boring. Once the too- difficult new meds were done away with, and my schedule tweaked, I still have mornings and late afternoons when I can do physical stuff, and if I get to the bar in the evening I can sit there until they throw me out. The next of my reprints, On the Edge of the Wild, with a new intro by Paula Young Lee and a cover by Vadim Gorbatov, is out soon-- see more a few posts past. After that is Eagle Dreams with a splendid black and white profile of the late Aralbai by Cat. And more to come.

Fall continues absent. My essentially northern soul (my Italian ancestors were in the Alps warring with Otzi after the Ice Age; most of the rest were mad melancholic Celts, mercenaries  fighting others of the same lineage in Scotland and later Ireland) is irritated by this golden weather everyone else loves. We should have had a hard frost  four weeks past; instead we have hot days and FLIES. Enough! Quail will start soon but I can never quite get in the mood for bird hunting unless there is a touch of frost, and your breath is visible when you open the back door just as the sun makes a bright edge over the mountains to the southeast...

I was having trouble with Rio; no, I was having trouble with my legs. Tavo Cruz came to my rescue without my having to ask, and will get him going, with me pitching in as I am able. Tavo is a biologist, a dog - in- law, and has a Gyr Merlin, so we can all relax. It is a much better solution than either giving him up or leaving him bored; so far Rio is free of vices, but boredom makes Gyrs as crazy as it does humans...

Work- we don't talk details, but I have had a sudden inspiration on how to proceed in my latest project-- perhaps why my subconscious now suggests I get back to work here too.
So: LINKS.

Turkish and Tunisian falconry are virtually identical, and I am told by Vadim that Georgia's is too. All use Eurasian Sparrow hawks caught on first passage using a mole cricket and a shrike; all employ a method that looks insane to us, throwing hawks like baseballs; though they know the hood, the birds are so well- manned that it hardly seems necessary to use the hood except in emergencies. The birds are flown as the migrant Coturnix quail move through, and can take astonishing bags. Once the quail have passed through, the hawkers release their birds.

There was a four -part YouTube on Turkish traditional hawking available for a while that had the look of being made for the state's educational TV company. These next two works are not as exhaustive, but are still fun. The first is this Vimeo of the Festival de L'epervier in Tunisia. No real hunting is done, but you can see real bird handling (the competition consists of tossing a quail off the side of a steep hill, then bowling a Spar after it). Some of the  Spars appear to be trailing 3 or four feet of string,  which doesn't slow them down much. The remarkable thing about this film is that falconry is obviously just a part of life, not some  strange exotic revival. Teenaged kids, young toughs and older working men hold forth on the virtues of their birds (one does see that the universal redneck signifier is redneck camo EVERYTHING-- have seen it as far from Magdalena, or Tunisia, as Bayan Olgii, and in Nick Fox's films of Southwest China). It makes a strange contrast to the old men in linen suits and finely woven broad brimmed straw hats...

Oh and-- don't take the written notes too seriously-- most of the birds are NOT "Barbary Peregrines" whatever that means-- most, and all but one flown (that by a dolt who treats a still- living quail as an inert object), are Accipiters, Spars, Accipiter nisus, and the exceptions look like Mediterranean Peregrines rather than the similar but distinct Barbary. One little guy is so calm and well- manned that he sits unhooded on the floorboard of a motor scooter, unhooded and unruffled, as his owner starts up and rides away.

The other link is to the White Review and is titled "The Forgotten Sea: the Falconers of the Eastern Pontos". Its tone is between that of a travel piece and a scholarly article; though the writer was not a falconer he kept his eyes open; this may be the most comprehensive of the accounts of this falconry I have read by anyone. The author seems to think Turkish falconry is dying, albeit  slowly. He certainly documents signs of its decadence: birds being kept after the season as pets because of their color; obsession with color rather than hunting ability; not flying special birds for fear of losing them... I approve of getting birds pet- TAME, but Spars that are not flown are not really hawks. Rio would make a better "pet" than any Accipiter nisus, but he is now learning to be a bird, as Libby puts it, with the attendant dangers and possibilities.

Jackson and Niki ALMOST made it up to the Black Sea coast last trip; let us hope that they can see it before this sort of magical survival disappears. As a Turkish speaker familiar with falconry since his childhood, he may bring back nuances yet unknown here.

Very different bird. You may have seen this little video of a Redtail taking down a drone, filmed BY the drone on the banks of the Charles (River, between Boston and Cambridge Massachusetts), but it is irresistible. I flew my old Redtail Cinammon less than a mile from there forty years ago, but never caught anything that exciting.


Cambridge hawker, '72?

My other links are not for the most part about birds, and I will put them in the next or another post. But first; remember how Robert Bakker, back in the nineteen eighties, called T rex "The Roadrunner from Hell"? And how Peter Larson, whose conviction and (I would say) unjust jailing for fossil offenses I don't quite understand even after reading about them, called it "The biggest bird of all"? I think that an actual paradigm shift is upon us, even as the nerds debate the producers over whether the "Velociraptors" in the next Jurassic Park episode should finally be allowed their feathers or stand shivering like plucked chickens. Bigger and bigger Tyrannosaurs are being discovered with feathers, especially Eutyrannus, and some dino kids are saying "why is the Tyrant King naked?"

Eutyrannus AND "Velociraptors"** in the snow

 Sensible, mostly young scientists, pointing to the acceptance of likely feathers on young rexes, ask when any adult in any birdlike line had no feathers when the young did. And now our most innovative paleoartist, John Conway, gives us a calm, feathered, close- mouthed Tyrannosaurus that is about the scariest thing I ever saw. He doesn't want to roar  at you***-- he just wants a snack!

* Who am I quoting? (A poet from his first book- whole stanza will appear).

** They are not Velociraptors, which were only coyote size-- more like, oh, Utahraptors--  but the name is better. You know those aspirin ads where some weary oldster has to tell a young person that Aspirin is not just for heart attacks? Kids either think I am being inventive, metaphorically, or that I am wrong (and correct me) when I refer to birds of prey as "raptors".

*** John McLoughlin used to roar himself: "WHY do they always show predators with their MOUTHS open, ROARING? They would all STARVE!"

"...all Dinosaurs had feathers"

The report (HT John Wilson) begins: "The first ever example of a plant-eating dinosaur with feathers and scales has been discovered in Russia. Previously only flesh-eating dinosaurs were known to have had feathers so this new find indicates that all dinosaurs could have been feathered."

The big thing here is the "all" I have been waiting for. Conceptually, this is huge.

The other key term is "Ornithschian", one of the two large divisions of Dinosaurs-- the plant- eating ones that often walk on four legs rather than two, including the duckbills and the Triceratops and its relatives. Some of us have thought  since the eighties that the meat- eating two legged Dinos, up to and including T rex (as Robert Bakker called it, "the 12000 pound Roadrunner from Hell"), were all feathered, and they did give rise to birds. But though we knew that some had weird bristly structures, it was less clear that the other group were feathered. Now it seems that from the start, maybe even before the Dino family split on two, that they came out of the Triassic extinctions wearing feathers. (There was a greater extinction  event BEFORE the Dinos, (see Out of Thin Air by Peter Ward), and its low- oxygen conditions may have caused the Dino- bird line to develop the air sacs, hollow bones, and efficient breathing that allow birds to fly over the Himalayas and "Brontosaurs"  to be agile moving animals even though they were bigger than my house).

In honor of all this, my favorite over- the- top depiction of the new standard, a feathered T rex attacking a "hairy" young Triceratops, and a dead Velociraptor by John Conway.

We Need More Feathered Dinos

John McLoughlin was writing about them in the late SEVENTIES. Isn't it time yet to acknowlege, preferably before the next Jurassic Park, that dinos resemble eagles and turkeys and Roadrunners more than, oh, fence lizards?

Especially with all the good artists around...

These last would be so good if they weren't lizard- naked!

This guy has known it for a long time...

And this one; well, these ones holding their long - ago first books in front of my house some years back, but I learned at least partly from the guy with the beard.

New Toy

Supposedly Archaeopteryx-- but except for the lack of the inner "killer claw" more of a typical feathered Theropod like Deinonychus.

Also see A Field Guide to Mesozoic Birds.

Feathered Tyrants

Are we finally having the sense to use feathers as the default condition on at least Theropod Dinos? New and new- ish examples of these smaller relatives of T rex would seem to argue "yes".

Add caption

Brian Switek muses on the state of the arthere.

See also the website of John Conway, the most startling and maybe the most interesting interpreter of Dinos I know of. Currently you are confronted by the scariest "birdy" T rex around when you go to his site.

(He also has the sense to depict his big predators with their mouths closed. John McLoughlin, one of the pioneers in depicting and imagining birdlike Dinosaurs, has been complaining about fossil carnivores with mouths agape for about 30 years).

Mahakala(s): Mongolian Free Association

I took a bunch of Mongolian artifacts to the Magdalena Library Saturday as visual aids to a talk by my friend Ian Jenness. He and his wife had taken the Trans- Siberian to Lake Baikal and Irkutsk, then dropped down to Ulan Bataar, spent a week or so in Mongolia in ger camps, then continued by rail through China.

I bought snuff boxes and 19th Century books and clothing and a muzzleloader and folk paintings, and several images of this guy:

Though he looks monstrous to Western eyes, he is in fact supposed to be a fierce protector; one of his "jobs" is Protector of Monasteries. This may well have special relevance to Mongolia in the past (and Tibet in the present?) Although Choibaltsan is sometimes called the Mongol Stalin, and ruled for about the same span of years, his reign was marked more by stultifying bureaucracy then terror-- except for monasteries and (as always with dictators?) minority tribes. I was once shown a cave where he had ordered 30 monks burned alive in the 50's, with soot still visible on the roof. It was refreshing to know that the family who showed me the cave were the proud parents of a novice monk, who took a day off to join us at our feast at their summer ger.

(From Wiki: " Choibalsan oversaw violent Soviet-ordered purges in the late 1930s that resulted in the deaths of an estimated 30,000 to 35,000 Mongolians; mostly Buddhist clergy, intelligentsia, political dissidents, ethnic Buryats and Khazaks, and other "enemies of the revolution." His intense persecution of Mongolia's Buddhists brought about their near complete extinction in the country.")

But wait-- there is more. Mahakala is also the genus of a small but taxonomically important feathered Mongolian Dino, a sort of roadrunner with a bony tail.

Brian Switek writes about his discovery here; and Carl Zimmer tell us how his lineage illuminates the bird- Dino lineage here.

Feathered Tyrants

It is almost 30 years since Robert Bakker referred to Tyrannosaurus rex as the "roadrunner from Hell". Some of us, like John McLaughlin, got the message right away. After all the intervening years, as the lines between "bird" and "dinosaur" have become blurrier and blurrier, the Zeitgeist is finally catching up. The first big "bird", below, is a recently discovered predecessor of T. rex, and definitely had feathers. The dramatic rendition below it reasonably shows the monster herself, as she might well have been. I suspect someone from the 1950s, when dinosaurs were lizards, would see these big birds as something out of science fiction.

First image from Science; second here.

Paleo Art comes of age...

Which doesn't mean gets dull and predictable. On the contrary, the abundance of "new" fossils  has given birth to a generation of artistic and scientific iconoclasts whose bold new vision is far more rooted in the past than any older generation's was. The inimitable polymath and prodigiously productive blogger Darren Naish, a serious anatomist, was raised on the same romantic classical dinos as I was; it is hard not to admire the old lizard- tailed reptiles as art, and their artists as virtuoso painters. But, as he says in the intro to All Yesterdays, an entertaining mixture of paleontology and art that could be a manifesto for the clear- eyed new breed of artist- scientists, "Rudolph F. Zallinger's animals-- most famously depicted in the Zallinger mural at Yale's Peabody Museum-- were clearly done with only a superficial reference to the skeletons of the species concerned." The great Charles Knight knew better, but he "...gave dinosaurs small, slender muscles that did not match their bones (dinosaurs actually seem to have had enormous, more bird- like muscles) and frequently drew dinosaurs freehand- style, again with what looks like poor attention to the proportions and nuances of the actual skeletons."

The old paradigm was overthrown in the seventies, when I was younger than Darren is now, by Ostrom at Yale and the flamboyant Robert Bakker out in the Badlands, and by John McLoughlin's first brilliant attempts to illustrate the dinos as, well, birds. But neither Bakker's description of Tyrannosaurus as a "Roadrunner from Hell",  nor McLoughlin's deadly genetically reconstructed Imperial pets in his his 1983 novel The Helix and the Sword , the Deinonychids Moscow and Washington, penetrated pop consciousness; Jurassic Park's big "Velociraptors" (not really), sisters of the Emperor's killers, were as reptilian as lizards, which made as much sense as having naked chickens or eagles walking around. Raptor types actually had feathers more like a goshawk's than a kiwi's, never mind scales-- we have found the feather insertions for big asymmetrical quills in their arms.

Bakker with dinosaur

McLoughlin self- portrait with "social hybrid of man and wolf" (his phrase)

Researchers and artists like Greg Paul and Luis Rey have since blown the old paradigm to hell with their properly birdy angular anatomy; Rey in particular adds wild primary colors and patterns, not because he knows what color they were but because both birds and for that matter lizards tend to use pattern and color in their rituals; the few fossils that show Mesozoic feather patterns indicate he is leaning in the right direction.

There are three new books that exemplify the new tradition. All Yesterdays is at once the most explicitly theoretical and "in your face", but also the most whimsical; Pterosaurs , by Mark Witton (who also has an excellent blog) is a genuine monograph by a expert, using the same rigorous standards, showing us what is known to date about creatures most people would assume were from another planet than ours, contemporary with not only dinosaurs but perfectly recognizable birds; A Field Guide to Mesozoic Birds and other Winged Dinosaurs by Matthew Martiniuk is the first book I know that simply poses various theropods and other later animals as though they were birds as to body carriage, how they hold their arms or wings-- something I see with relief and consider overdue-- and puts them in "Bird Guide" format.

The one for all naturalists with a sense of humor is All Yesterdays; after Darren declares that "this book is firmly grounded in a skeptical, rigorous, evidence- led effort to study and depict anatomy: the approach promoted by Paul, Anton, and the like...",  he reminds us that things like fat and feathers and integument, "manes, ruffs, , thick furry coats..."; not to mention behavior, can all affect appearance. Then he hands over the reins to artists John Conway and C.N. Kosemen and lets them run.

Every one of these reconstructions is original; some look rather like dinosaurs, some like odd little mammals (see the fluffy little Leaellynasaura, with its lemur tail held upright in a snowstorm); some are fairly conventional but doing unfamiliar things; one is fat, two invisible, and the Elasmosauruses in neck-swinging contests look more like sea worms in a colony than the Loch Ness monster. Perhaps my favorite is their reconstruction of the Therizinosaurus, the first depiction of this ridiculous beast that has made any sense to me at all: an upright, long-tongued avian giant sloth with kiwi feathers*, browsing high branches with a prehensile tongue.

The last chapter is hilarious: reconstructions of present-day animals by future paleontologists. The cat resembles a carnivorous iguanoid with mammalian teeth and staring eyes; swans and hornbills are reptilian and slick like yesterday's dinosaurs; the elephant has immense tusks but no trunk, the python legs, and the baboon is venomous. The most ridiculous, though no more so than some of today's versions, is a manatee that looks like a vegetarian lion, imaginatively reconstituted from a single bone, standing in its mountain meadow.

Pterosaurs is a serious scientific monograph illustrated by the author, with a thing on the cover that looks like an alien aircraft racing through a Martian sky.

 I am not qualified to judge it, only to read it in awe; I have read all the modern books on these flying creatures, and this is far and away the best. I do believe these are the oddest vertebrates ever to live on earth. They ranged from the size of a tiny songbird to the span at least of a large aircraft, and were astonishingly successful. The science is rigorous, the speculation intelligent, and the illustrations, though Witton is not a great artist, are breath-taking. Either you like this kind of thing or you don't. But I'll most likely keep this book until I die. Look at the examples here for a clue.

The last book is is striking in part because it is so familiar; the main difference between it and any bird guide you use is that a lot of these birds are scaled with a human figure, because some of them are pretty big. I have been looking for bland, placid silhouettes of things like Deinonychus and Velociraptor ever since John McLaughlin asked me (almost a dinosaurian eon ago) why the hell every carnivore in prehistory is shown with mouth agape, roaring. And why don't artists see how bird-like the hand structure of raptorial dinosaurs is? I don't mean to use the word "bland" as a criticism; what I mean is normal, unexcited. I expect if you were watching these creatures through binoculars and they didn't know you were there, they would look just like this.

Second from the top is that notorious fowl, Deinonychus herself

*Here is an almost believable version that is more courting pigeon than sloth.

Dino- birds

A good XKCD on one of our favorite subjects from Peculiar:

Tattoos, Griffins, Dinosaurs, and Indiana Jones

Our friend Sari in Finland sends this link to some tattooed mummies in the Siberian Altai. Here are a couple more from that tradition, from (I think) a bit further south.

These are mythical "Griffins", but are probably based on fossils like the Protoceratops, found in Mongolia in the 1920's by Roy Chapman Andrews, the real- life inspiration for Indiana Jones.

Some of his actual fossils are in the Museum in Ulan Bataar, where we have seen (and touched!) them.

The birth of the Griffin from the bones of a dinosaur is described well in Adrienne Mayor's The First Fossil Hunters .

Eevil Killer Dino- Birds

(With apologies to Darren).

Walter Hingley sends word of new theories coming out the Museum of the Rockies about the ever- closer similarities becoming apparent between raptorial dinos and modern raptors.

The illo is lurid but wonderful:


Of course some of us have always thought so, notably John McLoughlin. "Washington and Moscow..."

UPDATE:

Quote is from McL's 1983 (!) The Helix and the Sword. The tyrant of a post- apocalyptic civilization has a pair of "reconstituted" Deinonychids described as follows:

"...the Sisters found the tale of the Dinosauria, a lost race of bird-like beings that inhabited dread Earth long before the advent of human beings...they learned of the Deinonychid, a beast that walked on two legs like a bird but that possessed, in place of wings, terrible, three-fingered taloned hands... within the inmost recessed of the mammalian mind... survives an ancient racial memory, a black fear of the bird-beast Dinosauria. Knowing this, the Sisterhood grew for Lothar IV two twin Deinonychids...

"Man-high, smooth-coated with short blackly iridescent feathers, red of eye and each wearing a diamond-studded Regency orange collar, Washington and Moscow were delivered to Lothar IV by the Sisterhood."

And the names? They are from an ancient document about the destruction of civilization:

"Washington and Moscow have come to blows at last, and with them all of earth must die...for the talons of these beasts are steel and their breath Death itself."

UPDATE (by Matt):

I wondered when the notion of the velociraptor "killing talon" use might be equated to modern birds of prey.  I was never able to see how the slashing theory made sense, given how well hawks use their feet (grasping, not slashing) and how similar the anatomy looks.  Incedentally, the common depiction of the dino's inner talon being hinged upward never made sense to me either, but I assume the educated folks know this was so, and why?

As to the above article's mention that modern raptors "flap" to keep prey beneath them, they do---but not constantly.  Flapping to maintain upright posture is common when the prey is still struggling, but once subdued (and certainly once killed) the hawk's wings and tail become three parts of a tripod and simply provide leverage for tearing. 

An additional feature of the spread wings and tail (a posture falconers know as "mantling") is that it hides the prey.  I can see dino feathers serving both needs, the stabilization and the obfuscation, without ever needing to have developed flight.

Here's a video of my Harris from yesterday to illustrate, tearing meat from a fresh kill.



(Neutrino Cannon says: "Avian phylogeny, when studied long enough, will tempt you to mix headache medication and alcohol.")