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Re: Screaming dromaeosaur biplane killers of the air



Greg Paul (GSP1954@aol.com) wrote:

<Flight, Webster's ->

  From the Webster's New World Student Reference:

  Flight, 1. the act, manner, or power of flying. More definitions refer
to unrelated uses, as in "flight of fancy."
  Flying, 1. to move through the air in an aircraft or by using wings, as
a bird. 2. to wave or float in the air. 3. to move or pass swiftly.

  I sorta don't think of a brick being thrown through the air as "flying,"
but rather as "being thrown" or "tossed" or "dropped". This is my
operative use. Gliding animals and flying animals are similarly separated
since an animal that flies I use in my texts as a creature that can
achieve thrust after it is in the air, not just prior to it. Gliders
cannot increase thrust once in the air, and this is where I separate the
two. Sorry for lack of clarification prior to this.

<Reply: I never claimed the primaries were longer than the arms. In most 
flying birds the primaries are shorter than the arms, confusciusornids
being an interesting exception. What is true is that the primaries are
longer relative to the hands than they are in Archaeopteryx, and are
closer to the modern flying bird condition in this regard.>

Paul had written:

"Steve Czerkas was correct that the Johel dromaeosaurs have fully
developed 
arm wings. At the same time it turns out they had fully developed leg
wings 
too."

  Based on the restoration of Czerkas, the wing had feathers fully longer
than the arm, and the reference "fully developed arm wings" is in
contradiction to this, as the secondaries are similarly short, and in
actuality more so. More on this later. I took the above, as an inference
of what was meant, to mean that *Cryptovolans* was to be given wings as
similar to *Archaeopteryx*, where they are not as shown by new specimens
of the probably conspecific *M. gui*.

<<In *M. gui*, the secondaries wrap around the ulna on the right side, and
it is not likely there was a vacant space inboard of the elbow.>>
 
<R: Not sure what H means here.>

  References to absence of tertials in this form, as in *Archaeopteryx*.
Dann Pigdon's restoration explicitly shows this, and I took the
opportunity to present recently noticed evidence to the contrary. The
presence of the bases of feathers that progress inboard of the elbow do
not show reduced feathers and suggest, rather than indicate, that there
were tertials present. However, like *Archaeopteryx*, there is no proof
they were present, similar to the positive evidence that *Caudipteryx*
lacked tertials of any note as the secondaries reduce distally towards the
bone.

<R: How H can calculate such a ratio via photos and when the specimens are
damaged in these areas is a mystery.>

And:

  "When the wing is posed in a normal flight position it has a moderate,
fairly typical forest bird chord/span ratio,"

  How can one calculate that the wing was normal when the area is damaged,
as you have done? A statement that requires extension of the distal
secondaries beyond their preserved limits. In the holotype of *M. gui*,
however, it is observable in the upper, right arm, that the secondaries to
have a taper, and some are shorter than others more distal and well away
from the trailing fracture roughly 1.5 cm caudal on the slab. In some
places more inboard than the feathers I note, which appear to be attached
to the proximal ulna.

<R: H is setting up more strawman arguments here. As per my statement, the
 fact that the arm wings were about as large as those of birds,>

  Quantify which birds and how large. 

<and consisted of fully developed aerodynamic feathers, shows there is no
doubt they could generate all the lift needed for powered flight, ergo
they had the potential, to power fly via flapping.>

  As Paul notes in _Dinosaurs of the Air_, even flightless birds, such as
many of the flightless rails, still have aerodynamic wings and feathers,
though many (such as the ratites) do not. This still doesn't prove
anything.

<I do not "assume" Archaeopteryx could power fly. In DA I go into great
detail showing why Archaeopteryx is much better adapted for powered flight
than any known glider.>

  Once again, using corollaries to birds and dromaeosaurids that avoid
actual dynamic study of the arm to show how it equates to birds, and
demonstrates flight capability. Instead, one jumps to flight performance.
The characters, as are noted for *Sinornithosaurus* (pg. 239, for
instance), show that it, despite lacking a wing, "despite all of its
well-developed flight features." Assumed are that many features of several
non-flying theropods must have been flight related, not just used for
flight during bird evolution. Others, namely Ostrom (1979) and Gishlick
(2000), including work by Hopp and Orsen, have suggested if not pointed
out that many of these features are utile for purposes other than flight
and can be exapted to flight. But these are ignored to favor a
"neoflightless" scenario, despite using the same evidence with a revised
phylogenetic structure. This is why I refer to the theory as not being
more parsimonious, rather than more likely to be true, as claimed in the
book. Note, also, that I do not disagree with Paul. I feel the evidence is
very compelling ... just not _more_ compelling than the alternatives,
whether combined or separate.

<Gliders tend to have smaller airfoils, and lack flapping skeletal
adaptations and muscle supports which Arch has. Since the winged
dromaeosaurs are much better adapted for powered flight than Arch as I
detail in DA, they were better powered fliers than the latter.>

  I still fail to see how the features listed for "flight" prove it. The
authoritarianism continues to be sustained despite evidence to the
contrary that would make the data more questionable, or require statements
like "would suggest to the author that" or similarly. 

<R: H, as I explained in my posts, the wing area/mass ratio of the winged
dromaeosaurs plots in the middle of the avian range. That is enormous by
definition, since flying birds have enormous arm feather arrays. BPM 0001
has non-frayed arm feathers? It hardly has preserved feathers at all 
according to the original descriptions in 2000. The authors did not even
bother to describe the feathers of 0001 or 12430. I examined the small
hand feathers of NGMC and they are frayed in a manner similar to the
reduced wings of the nearly flightless kakapo.>

  This is apparent from photos of the specimen, which show cohesive vanes.
The "frayed" vanes of the type, as ignored above, probably relate to the
curvature of the rachis, absent in other specimens. This is apparent, once
again, in close-ups of the arm. Similar length of barbs, also, along the
vane show a constraint that appears to enforce the presence of barbules.
This does not occur in ratites, with "frayed" feathers, but do occur in
kakapo and even owl feathers, which have frayed edges, but not rails,
which lack them. Just because they occur in one relatively non-flying bird
(which does flap and can glide down from heights, so technically it
"flies", apart from some reports of flapping _up_) does not mean they are
universal. Paul points this out to me elsewhere as well, given another
assumption of "universality."

<[humeral elevators] you mean fully developed avian system, absent in bats
and confuciusornid grade birds>

  I do in fact refer to the M. supracoracoideus which, as restored for
*Archaeopteryx* (in PDW) is advanced above that of *Sinornithosaurus* with
a larger, taller acromion, with the incipient triosseal canal. This is
less derived in *Sinornithosaurus* and *Microraptor*.

<[reduced lateral coracoid edge] so?>

  I should have clarified this; the reduced lateral curvature in basal
birds reflects in increase in medial curvature and a lateralization of the
glenoid and broadening of the shoulder, which works toward a more advanced
pectoral arrangement as in modern birds, providing a sort of rotating or
"spring" system in the sternum and coracoid, medial compression of the
shoulder during the downstroke. This is the advance avian respiration
system. A greater curvature of the lateral edge of the coracoid, or
ventral edge, depending on orientation, also depends on the orientation
and relation of the arm depressors and rotators Mm. coracobrachialis
dorsalis and deltoideus minor, which respectively have become narrower and
taller, one becoming lateralized on the acrocoracoid (deltoideus) and the
other on the distal cranial surface of the transformed coracoid
(coracobrachialis). So.

<[lower coracoid tubercle]>

  No comments on this?

<[ossified or fused uncinates] entirely absent in flying screamers, did
you bother to carefully read DA and look at the pretty pictures I labored
over?>

  I might have paid more attention to photos, but I consider the
illustrations to be interpretations, expressive of ideas. As I would mine.
I try to illustrate as much as I can with photos first. However, because
screamers lack fused uncinates is irrelevant, the remainder of birds show
them present, and their absence in screamers is likely autapomorphic for a
group of birds (anseriforms) that possess them nearly universally, as well
as most ratites, tinamous, and nearly all other ornithothoracine birds.

<[fused carpus] absent in pterosaurs and bats>

  Several pterosaurs should a carpometacarpus, actually. And the
chiropteran flight mechanics are decidedly different from that of a bird,
including splayed metacarpals, where a carpometacarpus would be
detrimental to its _modus volati_. Notably, the only other fused carpus
appears to occur in oviraptorosaurs (*Oviraptor philoceratops* is claimed
to have a partial fused slc and second metacarpal, whereas *Heyuannia* has
the posteriorly [volarly] fused slc and first metacarpal [but not fused on
the dorsal surface of the manus]) along with a more avian-style skull,
braincase, sacral system, pneumaticity, and so forth. Equating flight and
avian evolution is another problem.

<[broadened proximal digits of the fingers] wrong, wrong, wrong, read the
literature and look at the published illustrations including DA before
stating such blatent untruths>

  Since I was using *Microraptor* and *Cryptovolans*, I was right, right,
right; I think this was evident in the rest of the original post and the
reply to the "winged Jehol theropods" as used by Paul in that post.
*Archaeopteryx* has a non-expanded first phalanx, despite claims to the
contrary, and *Sinornithosaurus* like *Confuciusornis* and *Jeholornis*
(more so in *C.*, and *J.* and *S.* are similar to one another in the
extent of the lateral crest, rather than showing a flight related increase
as the arm design becomes more modern; this would initially question the
use of the crest as a "flight" related structure beyond the obvious need
to reduce the bones lateral bending stress and possibly to increase the
leverage of the feathers attached to it). This is also absent in many
other basal birds, such as *Cathayornis*, though the type specimen of
*Sinornis* has what appears to be a broader first than second phalanx of
the second digit. If one could correlate how a broader first phalanx of
the first digit means anything to the advancement of flight, despite the
more advanced shoulder of enantiornithines.

<[venate alulae] R: absent in pterosaurs and bats, partly present in the 
flying dromaeosaurs>

  As previously described, my observation shows that there is no evidence
that the first digit feathers of NGMC 91 and *M. gui* had barbules, just
barbs. As such, they show no aerodynamic asymmetry or venation as in the
presence of barbules. The earliest true alula known occurs in *Eoalulavis*
from the LJ Las Hoyas of Spain. Similarly, pterosaurs and bats lack
feathers entirely, as well as asymmetrical ones and pinnate wings, and
remarking on their absence is ineffective, otherwise we'd be questioning
their flight ability.

<you ignore the actual data and the actual presence/absence of flight
adaptations in powered fliers>

  I was quite clear on them. I also, as noted previously, showed how many
features are of questionable relevance to the development of flight. Paul,
rather, has assumed the relationship of many of these "ignored" features
as being flight-related.

<there is far more data than you are aware of>

  Willing to elucidate on this unaware data? I am dealing with presented
data and an argument against a post presented to the list for observation.
Other unpublished data is similarly not presented for the sheer fact that
it is not published.

<R: No birds have wings on their legs. Citing bird and other dinosaur
femoral head morphology is entirely irrelevant, we are examining Jehol
dromaeosaurs here.>

  And I described how the femora were not capable of rotating dorsally by
lateral extension.

  Furthermore, it was Paul who originally compared the leg structure to
birds, as a reference of integumental similarity to birds.

"In all modern birds large, strongly asymmetrical distal primaries with
trim edges are always used for flight, display is at best a secondary
function. Since this form applies to the distal leg feathers the only
logical scientific conclusion is that they evolved primarily for flight,
and that display was at most a secondary use."

  As you note, birds are irrelevant here. Asymmetry of the feathers when
the leg was extended would require unusual and frankly impossible
positions of the metatarsus (when the leg was extended as in Xu et al.,
the feathers would point inward, not outward, as the feathers _trail_ the
metatarsus as the asymmetry favor the narrow vane towards the foot -- if
the condition of feather position is taphonomic and the feathers were
lateral to the metatarsus, the feathers would be oriented _vertically_;
when the leg was held caudally, the metatarsus was held horizontally, and
though the feathers are now lateral, the asymmetry is caudal, rather than
cranial; when the leg was tucked, as in birds, the metatarsus is
horizontal, the feathers face laterally, and the narrow vane was cranial,
not caudal. In the last, only then does the leg conform to the aerodynamic
feathers. This also explains the bowed and long fifth metatarsal, which
may have more likely bowed laterally as part of the feather support
structure, and not caudally as recently reconstructed.

  quoted from Paul (http://www.cmnh.org/dinoarch/2003Jan/msg00606.html):

"If the dromaeosaur's leg feathers were the same size yet symmetrical then
it could only be concluded that they were for display. But this is not the
case, ergo arguing that aerodynamic feathers were mainly for display is
not logical of scientific."

  This is also not true. A display feather cannot only be asymmetrical.
Lyrebirds and many swifts and hummingbirds have elongated asymmetrical
lateral retrices that serve display functions in their use. In swifts and
hummingbirds, they must be asymmetrical as they are also of use during
flight. Lyrebirds can also fly with their tails, as can the out
asymmetrical display feathers of peacocks (which can also fly).

  "Since the foot feathers could fold up relative to the metatarsus, I'm
not so sure they would have hindered movement on the ground -"

  We have no idea the feathers can fold, only assume they can. Unless
someone has that magic camera that can see the muscles of the calamus (or
the calamus, for that matter) that would tell us whether anything could
fold (one knows in bones because of joint surfaces, lest someone bring
this up as a contradiction).

"So does not contradict the arboreal adaptations of the Johel
dromaeosaurs."

  Which I never said did. In fact, my conclusions were largely that it was
arboreal.

  and back to the reply:

<The femoral head of the type Sinornithosaurus is dramatically different
in form from those of other dromaeosaurs, dinosaurs and birds - which in 
retrospect I missed because I had no idea of its importance - with no 
cylinderical form, the articular surface seeming to extend laterally
forming a proximally oriented spherical head, and no prominent lateral
trochanters that will interfer with a sprawling posture (this is correctly
figured in Fig 2 Nature 401:262, and can be seen in the accompanying
photo).>

  As I stated earlier, the caput is distorted relative to the trochanteric
crest and shows nothing reflecting a femoral neck, as indicated in the
photo in the paper, whereas the illustration implies the opposite.
Preservation would imply, if the femur were shown in medial view, that the
femoral head was exposed atop the neck, and would not show whether one,
despite its presence in other "sinornithosaurs," exists; if the condyle is
below the trochanter and the femur is exposed laterally, the same is true
of the neck. I am requesting Xu for a clearer image of the type, as Paul
does not appear willing to show the photo that verifies his statement when
the original photo is not of the best quality. The photo, rather than
showing a spherical, 3-D ball of a head, implies the head is flat, as in
ceratosaurs, and the apparent lateral curvature of the shaft (with
midshaft fracture) implies taphonomic distortion, despite the cranial
orientation of the head, which occurs no where else in maniraptorans, even
birds, and it would be unparsimonious to suggest it was present in the
face of available evidence, so I hardly think the case can be made on
*Sinornithosaurus*.

<Note: Oops. I forgot that the Microraptor type is also preserved with the
 legs splayed out, and without evidence for disarticulation although
damage makes the situation non-definitive. More evidence for sprawling!>

  And ignoring the broken femoral head in the holotype of *M. zhaoianus*,
and no femoral head exposed in the articulated left femur of CAGS 20-8-001
(despite preparation around both it and the right femur). And so what was
the trunk shaped in section in *Confuciusornis*? Isn't this usually based
on rib curvature?

<Contrary to these data, it seems the data I presented was overlooked a
tad. NGMC 91 lacks known humeral proximal ends {what does this have to do 
with LEG function?],>

  Paul was the one who is trying to make femora angle laterally ... as for
leg function, I never said anything about leg function.

<has nothing to do with the discussion of the Jehol dromaeosaurs>

  It shows, as I described, what a spherical, elevated humeral condyle
would look like, as implied in *Sinornithosaurus*, and a demonstration
that lateral leg splay was still prohibitive of anything even _close_ to
60 degrees lateral to the vertical. In fact, I doubt it would have gone
more than 45 degrees. In contrast, the elevated femoral head of *Ingenia*
occurs in a leg that when articulated, shows a femoral lateral extension
of about 30 degrees. The femur of *Bagaraatan* is similar to that of
(Ingenia* in the proximal end. These features of the femur are absent in
*Microraptor* where visible, and *Sinornithosaurus*; they are not
preserved in NGMC 91, and as I pointed out, the available evidence does
not indicate splay was possible beyond a typical theropod norm.

<R: Am not aware that anyone is arguing these birds could sprawl their 
wingless legs. Derived birds are often preserved on their backs or bellies
 because their bodies are flattened. That the deeper bodied Jehol
dromaeosaurs are sometimes preserved splayed out unlike the similarly deep
bodied Archaeopteryx suggests that the leg winged droms were able to
sprawl their hindlimbs, unlike the winglegless Arch.>

  Then it is ridiculous to argue that splay is indicated in body posture
of preservation. As shown in *M. gui*, the hip was much shallower than in
early birds or *Archaeopteryx* with the exception of *Confuciusornis*, as
the opisthopubic pelvis has a pubis that curves caudally so that
articulated appears to have been nearly horizontal.

<Note: It is interesting that even derived flightless dromaeosaurs often
have 7a partial closing off of the acetabulem, which is also seen in some
birds. I noticed this in the 80s but thought nothing little of it, is
probably a retention of the earlier sprawling condition.>

  Nearly all theropods have some medial acetabular closure, more so in
maniraptorans than not. In *Sinornithosaurus*, only the pubic peduncle has
a medial flange. And this still doesn't tell us about leg sprawl. Or even
implies it was ancestrally present. To articulate the femur of any bird or
?sinornithosaurs? laterally, one dislocates the femoral condyle from the
acetabulum, there is no way around this. As also described above, the
leg-wings and "buttfans" serve aerodynamic function when the leg is
tucked, not extended. I will prepare a figure online to describe this.

<R: Incoherent argument. If the leg feathers evolved from smaller airfoils
into larger display-only feathers they would have lost the asymmetry,>

  How so?

<as occurs in birds when feathers are not used for flight (if anyone can
point to a well documented case in which avian asymmetrical feathers are
used for display rather than flight please let us know).>

  See above. Two examples: Lyrebird and peacock. And yes, the outer
retrices of the peacock are more asymmetrical than the inner.

<The leg feathers of the winged dromaeosaurs were therefore used for
flight.>

  In the opinion of the author with the data he has chosen to consider
relevant to his case.

<Since there is no evidence for the ability to flap the legs the leg
feathers were purely for generating lift for pertinent purposes, they did
not generate thrust.>

  Kicking motion with pes held vertically during horizontal glide path? I
think this was suggested before.

<R: Evolve fully developed, aerodynamicwings with associated skeletal and 
muscle adaptations for shade? Surely you pull our legs.>

  The idea of the wing structure as developed by others, not I, and has
been illustrated on this list, so others should be aware of them even if
they chose to dismiss them out of hand or that their evidence was better:

  1) for aerodynamic running (Hartman, 2000, SVP presentation and poster)
of which *Caudipteryx* may be a precursor, the use of running achieving
lift would cause, as in leaping origins of flight, asymmetry of the
feathers; this is remarkably predicatory of Dial (2003) in the
wing-assisted incline running, which may be a parallel or extended dynamic
of the running hypothesis

  2) for nesting shades or brooding (Hopp and Orsen, 1997 Dinofest
presentation, in press) where need to protect nests and larger broods
would cause the wings to become larger; any further need to run or use of
WAIR would cause asymmetry; this hypothesis is consistently precursory to
other ground-up origins of flight, and (2) may lead to (1). Contact with
the ground would cause the outer primaries to narrow the "leading vane"
for protective purposes, as well, and could also explain asymmetry on its
own, in a non-aerodynamic way.

  3) for predation (Ostrom, 1979, and others) where need to catch or hold
prey would cause the arms to develop all the neccessary mechanics of
flight, as I detailed a long time ago in my allusion to cats on this list.
(My name and "cats" should be adequate search parameters in the Dino List
archives.) Though Ostrom originally attempted to support this mechanic
with wings to create an insect net (for *Archaeopteryx*), the exaptation
of manual claws larger than contemporary sister groups or with greater
curvature suggests that the prey may have been larger than insects. This
explains the wing folding and humeral elevator system. This is also
consistent with theories (1) and (2).

  4) for climbing (I think Tim Williams is the most vocal proponent of
this, and I am unaware apart from Chatterjee (1998) of anywhere it has
been published in similar manner) where the sheer act of climbing causes
the arm and shoulder adaptations assumed to be "flying" in nature,
including the medial action of the arm, folding during lifting the body
(there are a few illustrations of this on the Dinosauricon, for
illustrative purposes), and increased curvature of the manual claws. This
is consistent with (1) and (2), and while it does not explain the
development of feathers as in (1) or (2), it is not impossible that
combinations of all four may have occurred.
  
  None of these hypotheses require the wing to be developed in an unknown,
yet-to-be-discovered animal, and can be corroborated with currently known
animals. In _Dinosaurs of the Air_, a hypothetical, unknown urvogel is
created which may explain the more advanced earlier fliers, whereas the
fossil record despite the so-called temporal paradox appears to support an
alternate phylogeny that Paul fails to disprove. And this is good, because
he offers only an alternative. This is not good, because he offers it as
authoritarian as Liaoning feathered theropods are secondarily flightless,
rather than pro-urvögeln.

<On the specimens the foot feathers are folded proximally relative to the 
metatarsus at an angle that would help them keep clear of the ground
during normal ground locomotion. This may be a fixed posture. But that
would make the feathers difficult to use for flight, or display for that
matter.>

  They are still broad enough for display. They do not need to be a
Chinese fan in shape to display. And similarly, birds today do not use
their asymmetrical feathers in a perpetual perpendicular to the air
stream, but slanted backwards, and that is what is suggested with the
position of the feathers.

<Of course birds can control the orientation of many of their feathers via
dermal muscles.>

  Of course they can. But when did these evolve? Even on the tail of
*Archaeopteryx*, could they have changed the shape of the tail? And
where's the evidence for this? The only evidence we have is the preserved
position of the feathers.

<Huh? Mostly incoherent. In any case biplane is biplane, it is not
necessary to always describe what kind.>

  True, and talking to Jim, I realized that, though I used the classic
structure of a stacked biplane to mean biplane, and use of canards as
non-evidentiary of the term "biplane", I had not thought of the staggered
biplane design. However, different biplane arrangements behave
differently, and in describing biplane-parallel animals, it would be nice
to describe them differently, so that the thread that spawned discussion
of different biplanes does not occur as a result of [admittedly, my]
confusion.

<It would be helpful if H would become more familiar with the data and be
sure his writing is more understandable in order to avoid misleading
folks. Then I would not need to spend so much time correcting the errors.>

  I could say the same thing. The authoritarian mindset often blinds
itself to alternative data, and though I do not state that Paul did not
know this, I do say that he rejected data that did not agree with his
theories, even when they contradicted them. I also feel I am familiar with
the animals. Maybe my aerodynamic studies (as Jim can attest to) could use
a bit more work, but the shear lack of decisive biomechanical work (as in
"flapping") in previous posts has led me to argue against statements of
flight and wing-structure that ignores this data. Similarly, it seems that
in illustrating data as decisive, it was in face equivocal, and I posted
originally to point this data out as non-indicative of the conclusions
being ascribed to it. Though this data is used to support a theory
alternative to the published phylogenetic data and the evolutionary
scenario of wing development derived from it, there is just as much, if
not more, non-flight related data that postulates alternative theories.

  Cheers,


Greg Paul (GSP1954@aol.com) wrote:

<Flight, Webster's ->

  From the Webster's New World Student Reference:

  Flight, 1. the act, manner, or power of flying. More definitions refer
to unrelated uses, as in "flight of fancy."
  Flying, 1. to move through the air in an aircraft or by using wings, as
a bird. 2. to wave or float in the air. 3. to move or pass swiftly.

  I sorta don't think of a brick being thrown through the air as "flying,"
but rather as "being thrown" or "tossed" or "dropped". This is my
operative use. Gliding animals and flying animals are similarly separated
since an animal that flies I use in my texts as a creature that can
achieve thrust after it is in the air, not just prior to it. Gliders
cannot increase thrust once in the air, and this is where I separate the
two. Sorry for lack of clarification prior to this.

<Reply: I never claimed the primaries were longer than the arms. In most 
flying birds the primaries are shorter than the arms, confusciusornids
being an interesting exception. What is true is that the primaries are
longer relative to the hands than they are in Archaeopteryx, and are
closer to the modern flying bird condition in this regard.>

Paul had written:

"Steve Czerkas was correct that the Johel dromaeosaurs have fully
developed 
arm wings. At the same time it turns out they had fully developed leg
wings 
too."

  Based on the restoration of Czerkas, the wing had feathers fully longer
than the arm, and the reference "fully developed arm wings" is in
contradiction to this, as the secondaries are similarly short, and in
actuality more so. More on this later. I took the above, as an inference
of what was meant, to mean that *Cryptovolans* was to be given wings as
similar to *Archaeopteryx*, where they are not as shown by new specimens
of the probably conspecific *M. gui*.

<<In *M. gui*, the secondaries wrap around the ulna on the right side, and
it is not likely there was a vacant space inboard of the elbow.>>
 
<R: Not sure what H means here.>

  References to absence of tertials in this form, as in *Archaeopteryx*.
Dann Pigdon's restoration explicitly shows this, and I took the
opportunity to present recently noticed evidence to the contrary. The
presence of the bases of feathers that progress inboard of the elbow do
not show reduced feathers and suggest, rather than indicate, that there
were tertials present. However, like *Archaeopteryx*, there is no proof
they were present, similar to the positive evidence that *Caudipteryx*
lacked tertials of any note as the secondaries reduce distally towards the
bone.

<R: How H can calculate such a ratio via photos and when the specimens are
damaged in these areas is a mystery.>

And:

  "When the wing is posed in a normal flight position it has a moderate,
fairly typical forest bird chord/span ratio,"

  How can one calculate that the wing was normal when the area is damaged,
as you have done? A statement that requires extension of the distal
secondaries beyond their preserved limits. In the holotype of *M. gui*,
however, it is observable in the upper, right arm, that the secondaries to
have a taper, and some are shorter than others more distal and well away
from the trailing fracture roughly 1.5 cm caudal on the slab. In some
places more inboard than the feathers I note, which appear to be attached
to the proximal ulna.

<R: H is setting up more strawman arguments here. As per my statement, the
 fact that the arm wings were about as large as those of birds,>

  Quantify which birds and how large. 

<and consisted of fully developed aerodynamic feathers, shows there is no
doubt they could generate all the lift needed for powered flight, ergo
they had the potential, to power fly via flapping.>

  As Paul notes in _Dinosaurs of the Air_, even flightless birds, such as
many of the flightless rails, still have aerodynamic wings and feathers,
though many (such as the ratites) do not. This still doesn't prove
anything.

<I do not "assume" Archaeopteryx could power fly. In DA I go into great
detail showing why Archaeopteryx is much better adapted for powered flight
than any known glider.>

  Once again, using corollaries to birds and dromaeosaurids that avoid
actual dynamic study of the arm to show how it equates to birds, and
demonstrates flight capability. Instead, one jumps to flight performance.
The characters, as are noted for *Sinornithosaurus* (pg. 239, for
instance), show that it, despite lacking a wing, "despite all of its
well-developed flight features." Assumed are that many features of several
non-flying theropods must have been flight related, not just used for
flight during bird evolution. Others, namely Ostrom (1979) and Gishlick
(2000), including work by Hopp and Orsen, have suggested if not pointed
out that many of these features are utile for purposes other than flight
and can be exapted to flight. But these are ignored to favor a
"neoflightless" scenario, despite using the same evidence with a revised
phylogenetic structure. This is why I refer to the theory as not being
more parsimonious, rather than more likely to be true, as claimed in the
book. Note, also, that I do not disagree with Paul. I feel the evidence is
very compelling ... just not _more_ compelling than the alternatives,
whether combined or separate.

<Gliders tend to have smaller airfoils, and lack flapping skeletal
adaptations and muscle supports which Arch has. Since the winged
dromaeosaurs are much better adapted for powered flight than Arch as I
detail in DA, they were better powered fliers than the latter.>

  I still fail to see how the features listed for "flight" prove it. The
authoritarianism continues to be sustained despite evidence to the
contrary that would make the data more questionable, or require statements
like "would suggest to the author that" or similarly. 

<R: H, as I explained in my posts, the wing area/mass ratio of the winged
dromaeosaurs plots in the middle of the avian range. That is enormous by
definition, since flying birds have enormous arm feather arrays. BPM 0001
has non-frayed arm feathers? It hardly has preserved feathers at all 
according to the original descriptions in 2000. The authors did not even
bother to describe the feathers of 0001 or 12430. I examined the small
hand feathers of NGMC and they are frayed in a manner similar to the
reduced wings of the nearly flightless kakapo.>

  This is apparent from photos of the specimen, which show cohesive vanes.
The "frayed" vanes of the type, as ignored above, probably relate to the
curvature of the rachis, absent in other specimens. This is apparent, once
again, in close-ups of the arm. Similar length of barbs, also, along the
vane show a constraint that appears to enforce the presence of barbules.
This does not occur in ratites, with "frayed" feathers, but do occur in
kakapo and even owl feathers, which have frayed edges, but not rails,
which lack them. Just because they occur in one relatively non-flying bird
(which does flap and can glide down from heights, so technically it
"flies", apart from some reports of flapping _up_) does not mean they are
universal. Paul points this out to me elsewhere as well, given another
assumption of "universality."

<[humeral elevators] you mean fully developed avian system, absent in bats
and confuciusornid grade birds>

  I do in fact refer to the M. supracoracoideus which, as restored for
*Archaeopteryx* (in PDW) is advanced above that of *Sinornithosaurus* with
a larger, taller acromion, with the incipient triosseal canal. This is
less derived in *Sinornithosaurus* and *Microraptor*.

<[reduced lateral coracoid edge] so?>

  I should have clarified this; the reduced lateral curvature in basal
birds reflects in increase in medial curvature and a lateralization of the
glenoid and broadening of the shoulder, which works toward a more advanced
pectoral arrangement as in modern birds, providing a sort of rotating or
"spring" system in the sternum and coracoid, medial compression of the
shoulder during the downstroke. This is the advance avian respiration
system. A greater curvature of the lateral edge of the coracoid, or
ventral edge, depending on orientation, also depends on the orientation
and relation of the arm depressors and rotators Mm. coracobrachialis
dorsalis and deltoideus minor, which respectively have become narrower and
taller, one becoming lateralized on the acrocoracoid (deltoideus) and the
other on the distal cranial surface of the transformed coracoid
(coracobrachialis). So.

<[lower coracoid tubercle]>

  No comments on this?

<[ossified or fused uncinates] entirely absent in flying screamers, did
you bother to carefully read DA and look at the pretty pictures I labored
over?>

  I might have paid more attention to photos, but I consider the
illustrations to be interpretations, expressive of ideas. As I would mine.
I try to illustrate as much as I can with photos first. However, because
screamers lack fused uncinates is irrelevant, the remainder of birds show
them present, and their absence in screamers is likely autapomorphic for a
group of birds (anseriforms) that possess them nearly universally, as well
as most ratites, tinamous, and nearly all other ornithothoracine birds.

<[fused carpus] absent in pterosaurs and bats>

  Several pterosaurs should a carpometacarpus, actually. And the
chiropteran flight mechanics are decidedly different from that of a bird,
including splayed metacarpals, where a carpometacarpus would be
detrimental to its _modus volati_. Notably, the only other fused carpus
appears to occur in oviraptorosaurs (*Oviraptor philoceratops* is claimed
to have a partial fused slc and second metacarpal, whereas *Heyuannia* has
the posteriorly [volarly] fused slc and first metacarpal [but not fused on
the dorsal surface of the manus]) along with a more avian-style skull,
braincase, sacral system, pneumaticity, and so forth. Equating flight and
avian evolution is another problem.

<[broadened proximal digits of the fingers] wrong, wrong, wrong, read the
literature and look at the published illustrations including DA before
stating such blatent untruths>

  Since I was using *Microraptor* and *Cryptovolans*, I was right, right,
right; I think this was evident in the rest of the original post and the
reply to the "winged Jehol theropods" as used by Paul in that post.
*Archaeopteryx* has a non-expanded first phalanx, despite claims to the
contrary, and *Sinornithosaurus* like *Confuciusornis* and *Jeholornis*
(more so in *C.*, and *J.* and *S.* are similar to one another in the
extent of the lateral crest, rather than showing a flight related increase
as the arm design becomes more modern; this would initially question the
use of the crest as a "flight" related structure beyond the obvious need
to reduce the bones lateral bending stress and possibly to increase the
leverage of the feathers attached to it). This is also absent in many
other basal birds, such as *Cathayornis*, though the type specimen of
*Sinornis* has what appears to be a broader first than second phalanx of
the second digit. If one could correlate how a broader first phalanx of
the first digit means anything to the advancement of flight, despite the
more advanced shoulder of enantiornithines.

<[venate alulae] R: absent in pterosaurs and bats, partly present in the 
flying dromaeosaurs>

  As previously described, my observation shows that there is no evidence
that the first digit feathers of NGMC 91 and *M. gui* had barbules, just
barbs. As such, they show no aerodynamic asymmetry or venation as in the
presence of barbules. The earliest true alula known occurs in *Eoalulavis*
from the LJ Las Hoyas of Spain. Similarly, pterosaurs and bats lack
feathers entirely, as well as asymmetrical ones and pinnate wings, and
remarking on their absence is ineffective, otherwise we'd be questioning
their flight ability.

<you ignore the actual data and the actual presence/absence of flight
adaptations in powered fliers>

  I was quite clear on them. I also, as noted previously, showed how many
features are of questionable relevance to the development of flight. Paul,
rather, has assumed the relationship of many of these "ignored" features
as being flight-related.

<there is far more data than you are aware of>

  Willing to elucidate on this unaware data? I am dealing with presented
data and an argument against a post presented to the list for observation.
Other unpublished data is similarly not presented for the sheer fact that
it is not published.

<R: No birds have wings on their legs. Citing bird and other dinosaur
femoral head morphology is entirely irrelevant, we are examining Jehol
dromaeosaurs here.>

  And I described how the femora were not capable of rotating dorsally by
lateral extension.

  Furthermore, it was Paul who originally compared the leg structure to
birds, as a reference of integumental similarity to birds.

"In all modern birds large, strongly asymmetrical distal primaries with
trim edges are always used for flight, display is at best a secondary
function. Since this form applies to the distal leg feathers the only
logical scientific conclusion is that they evolved primarily for flight,
and that display was at most a secondary use."

  As you note, birds are irrelevant here. Asymmetry of the feathers when
the leg was extended would require unusual and frankly impossible
positions of the metatarsus (when the leg was extended as in Xu et al.,
the feathers would point inward, not outward, as the feathers _trail_ the
metatarsus as the asymmetry favor the narrow vane towards the foot -- if
the condition of feather position is taphonomic and the feathers were
lateral to the metatarsus, the feathers would be oriented _vertically_;
when the leg was held caudally, the metatarsus was held horizontally, and
though the feathers are now lateral, the asymmetry is caudal, rather than
cranial; when the leg was tucked, as in birds, the metatarsus is
horizontal, the feathers face laterally, and the narrow vane was cranial,
not caudal. In the last, only then does the leg conform to the aerodynamic
feathers. This also explains the bowed and long fifth metatarsal, which
may have more likely bowed laterally as part of the feather support
structure, and not caudally as recently reconstructed.

  quoted from Paul (http://www.cmnh.org/dinoarch/2003Jan/msg00606.html):

"If the dromaeosaur's leg feathers were the same size yet symmetrical then
it could only be concluded that they were for display. But this is not the
case, ergo arguing that aerodynamic feathers were mainly for display is
not logical of scientific."

  This is also not true. A display feather cannot only be asymmetrical.
Lyrebirds and many swifts and hummingbirds have elongated asymmetrical
lateral retrices that serve display functions in their use. In swifts and
hummingbirds, they must be asymmetrical as they are also of use during
flight. Lyrebirds can also fly with their tails, as can the out
asymmetrical display feathers of peacocks (which can also fly).

  "Since the foot feathers could fold up relative to the metatarsus, I'm
not so sure they would have hindered movement on the ground -"

  We have no idea the feathers can fold, only assume they can. Unless
someone has that magic camera that can see the muscles of the calamus (or
the calamus, for that matter) that would tell us whether anything could
fold (one knows in bones because of joint surfaces, lest someone bring
this up as a contradiction).

"So does not contradict the arboreal adaptations of the Johel
dromaeosaurs."

  Which I never said did. In fact, my conclusions were largely that it was
arboreal.

  and back to the reply:

<The femoral head of the type Sinornithosaurus is dramatically different
in form from those of other dromaeosaurs, dinosaurs and birds - which in 
retrospect I missed because I had no idea of its importance - with no 
cylinderical form, the articular surface seeming to extend laterally
forming a proximally oriented spherical head, and no prominent lateral
trochanters that will interfer with a sprawling posture (this is correctly
figured in Fig 2 Nature 401:262, and can be seen in the accompanying
photo).>

  As I stated earlier, the caput is distorted relative to the trochanteric
crest and shows nothing reflecting a femoral neck, as indicated in the
photo in the paper, whereas the illustration implies the opposite.
Preservation would imply, if the femur were shown in medial view, that the
femoral head was exposed atop the neck, and would not show whether one,
despite its presence in other "sinornithosaurs," exists; if the condyle is
below the trochanter and the femur is exposed laterally, the same is true
of the neck. I am requesting Xu for a clearer image of the type, as Paul
does not appear willing to show the photo that verifies his statement when
the original photo is not of the best quality. The photo, rather than
showing a spherical, 3-D ball of a head, implies the head is flat, as in
ceratosaurs, and the apparent lateral curvature of the shaft (with
midshaft fracture) implies taphonomic distortion, despite the cranial
orientation of the head, which occurs no where else in maniraptorans, even
birds, and it would be unparsimonious to suggest it was present in the
face of available evidence, so I hardly think the case can be made on
*Sinornithosaurus*.

<Note: Oops. I forgot that the Microraptor type is also preserved with the
 legs splayed out, and without evidence for disarticulation although
damage makes the situation non-definitive. More evidence for sprawling!>

  And ignoring the broken femoral head in the holotype of *M. zhaoianus*,
and no femoral head exposed in the articulated left femur of CAGS 20-8-001
(despite preparation around both it and the right femur). And so what was
the trunk shaped in section in *Confuciusornis*? Isn't this usually based
on rib curvature?

<Contrary to these data, it seems the data I presented was overlooked a
tad. NGMC 91 lacks known humeral proximal ends {what does this have to do 
with LEG function?],>

  Paul was the one who is trying to make femora angle laterally ... as for
leg function, I never said anything about leg function.

<has nothing to do with the discussion of the Jehol dromaeosaurs>

  It shows, as I described, what a spherical, elevated humeral condyle
would look like, as implied in *Sinornithosaurus*, and a demonstration
that lateral leg splay was still prohibitive of anything even _close_ to
60 degrees lateral to the vertical. In fact, I doubt it would have gone
more than 45 degrees. In contrast, the elevated femoral head of *Ingenia*
occurs in a leg that when articulated, shows a femoral lateral extension
of about 30 degrees. The femur of *Bagaraatan* is similar to that of
(Ingenia* in the proximal end. These features of the femur are absent in
*Microraptor* where visible, and *Sinornithosaurus*; they are not
preserved in NGMC 91, and as I pointed out, the available evidence does
not indicate splay was possible beyond a typical theropod norm.

<R: Am not aware that anyone is arguing these birds could sprawl their 
wingless legs. Derived birds are often preserved on their backs or bellies
 because their bodies are flattened. That the deeper bodied Jehol
dromaeosaurs are sometimes preserved splayed out unlike the similarly deep
bodied Archaeopteryx suggests that the leg winged droms were able to
sprawl their hindlimbs, unlike the winglegless Arch.>

  Then it is ridiculous to argue that splay is indicated in body posture
of preservation. As shown in *M. gui*, the hip was much shallower than in
early birds or *Archaeopteryx* with the exception of *Confuciusornis*, as
the opisthopubic pelvis has a pubis that curves caudally so that
articulated appears to have been nearly horizontal.

<Note: It is interesting that even derived flightless dromaeosaurs often
have 7a partial closing off of the acetabulem, which is also seen in some
birds. I noticed this in the 80s but thought nothing little of it, is
probably a retention of the earlier sprawling condition.>

  Nearly all theropods have some medial acetabular closure, more so in
maniraptorans than not. In *Sinornithosaurus*, only the pubic peduncle has
a medial flange. And this still doesn't tell us about leg sprawl. Or even
implies it was ancestrally present. To articulate the femur of any bird or
?sinornithosaurs? laterally, one dislocates the femoral condyle from the
acetabulum, there is no way around this. As also described above, the
leg-wings and "buttfans" serve aerodynamic function when the leg is
tucked, not extended. I will prepare a figure online to describe this.

<R: Incoherent argument. If the leg feathers evolved from smaller airfoils
into larger display-only feathers they would have lost the asymmetry,>

  How so?

<as occurs in birds when feathers are not used for flight (if anyone can
point to a well documented case in which avian asymmetrical feathers are
used for display rather than flight please let us know).>

  See above. Two examples: Lyrebird and peacock. And yes, the outer
retrices of the peacock are more asymmetrical than the inner.

<The leg feathers of the winged dromaeosaurs were therefore used for
flight.>

  In the opinion of the author with the data he has chosen to consider
relevant to his case.

<Since there is no evidence for the ability to flap the legs the leg
feathers were purely for generating lift for pertinent purposes, they did
not generate thrust.>

  Kicking motion with pes held vertically during horizontal glide path? I
think this was suggested before.

<R: Evolve fully developed, aerodynamicwings with associated skeletal and 
muscle adaptations for shade? Surely you pull our legs.>

  The idea of the wing structure as developed by others, not I, and has
been illustrated on this list, so others should be aware of them even if
they chose to dismiss them out of hand or that their evidence was better:

  1) for aerodynamic running (Hartman, 2000, SVP presentation and poster)
of which *Caudipteryx* may be a precursor, the use of running achieving
lift would cause, as in leaping origins of flight, asymmetry of the
feathers; this is remarkably predicatory of Dial (2003) in the
wing-assisted incline running, which may be a parallel or extended dynamic
of the running hypothesis

  2) for nesting shades or brooding (Hopp and Orsen, 1997 Dinofest
presentation, in press) where need to protect nests and larger broods
would cause the wings to become larger; any further need to run or use of
WAIR would cause asymmetry; this hypothesis is consistently precursory to
other ground-up origins of flight, and (2) may lead to (1). Contact with
the ground would cause the outer primaries to narrow the "leading vane"
for protective purposes, as well, and could also explain asymmetry on its
own, in a non-aerodynamic way.

  3) for predation (Ostrom, 1979, and others) where need to catch or hold
prey would cause the arms to develop all the neccessary mechanics of
flight, as I detailed a long time ago in my allusion to cats on this list.
(My name and "cats" should be adequate search parameters in the Dino List
archives.) Though Ostrom originally attempted to support this mechanic
with wings to create an insect net (for *Archaeopteryx*), the exaptation
of manual claws larger than contemporary sister groups or with greater
curvature suggests that the prey may have been larger than insects. This
explains the wing folding and humeral elevator system. This is also
consistent with theories (1) and (2).

  4) for climbing (I think Tim Williams is the most vocal proponent of
this, and I am unaware apart from Chatterjee (1998) of anywhere it has
been published in similar manner) where the sheer act of climbing causes
the arm and shoulder adaptations assumed to be "flying" in nature,
including the medial action of the arm, folding during lifting the body
(there are a few illustrations of this on the Dinosauricon, for
illustrative purposes), and increased curvature of the manual claws. This
is consistent with (1) and (2), and while it does not explain the
development of feathers as in (1) or (2), it is not impossible that
combinations of all four may have occurred.
  
  None of these hypotheses require the wing to be developed in an unknown,
yet-to-be-discovered animal, and can be corroborated with currently known
animals. In _Dinosaurs of the Air_, a hypothetical, unknown urvogel is
created which may explain the more advanced earlier fliers, whereas the
fossil record despite the so-called temporal paradox appears to support an
alternate phylogeny that Paul fails to disprove. And this is good, because
he offers only an alternative. This is not good, because he offers it as
authoritarian as Liaoning feathered theropods are secondarily flightless,
rather than pro-urvögeln.

<On the specimens the foot feathers are folded proximally relative to the 
metatarsus at an angle that would help them keep clear of the ground
during normal ground locomotion. This may be a fixed posture. But that
would make the feathers difficult to use for flight, or display for that
matter.>

  They are still broad enough for display. They do not need to be a
Chinese fan in shape to display. And similarly, birds today do not use
their asymmetrical feathers in a perpetual perpendicular to the air
stream, but slanted backwards, and that is what is suggested with the
position of the feathers.

<Of course birds can control the orientation of many of their feathers via
dermal muscles.>

  Of course they can. But when did these evolve? Even on the tail of
*Archaeopteryx*, could they have changed the shape of the tail? And
where's the evidence for this? The only evidence we have is the preserved
position of the feathers.

<Huh? Mostly incoherent. In any case biplane is biplane, it is not
necessary to always describe what kind.>

  True, and talking to Jim, I realized that, though I used the classic
structure of a stacked biplane to mean biplane, and use of canards as
non-evidentiary of the term "biplane", I had not thought of the staggered
biplane design. However, different biplane arrangements behave
differently, and in describing biplane-parallel animals, it would be nice
to describe them differently, so that the thread that spawned discussion
of different biplanes does not occur as a result of [admittedly, my]
confusion.

<It would be helpful if H would become more familiar with the data and be
sure his writing is more understandable in order to avoid misleading
folks. Then I would not need to spend so much time correcting the errors.>

  I could say the same thing. The authoritarian mindset often blinds
itself to alternative data, and though I do not state that Paul did not
know this, I do say that he rejected data that did not agree with his
theories, even when they contradicted them. I also feel I am familiar with
the animals. Maybe my aerodynamic studies (as Jim can attest to) could use
a bit more work, but the shear lack of decisive biomechanical work (as in
"flapping") in previous posts has led me to argue against statements of
flight and wing-structure that ignores this data. Similarly, it seems that
in illustrating data as decisive, it was in face equivocal, and I posted
originally to point this data out as non-indicative of the conclusions
being ascribed to it. Though this data is used to support a theory
alternative to the published phylogenetic data and the evolutionary
scenario of wing development derived from it, there is just as much, if
not more, non-flight related data that postulates alternative theories.

  Cheers,


=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

__________________________________________________
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