Archaeopteryx not the first bird, is the earliest known (powered) flying dinosaur

[GSP1954@aol.com]

Even though I still have issues with cladistics, it is nice to see a major 
cladistic study finally show a large body of sickle clawed dinosaurs closer to 
the rest of Aves than Archaeopteryx as per the Mayr et al Science paper (even 
though a host of characters that further reinforce this conclusion were not 
included). Kind of reminds me of that noncomputational cladogram showing 
secondarily flightless deinonychosaurs closer to birds than Archaeopteryx that 
was 
published back in 84. One particular point I find quirky is Microraptor being 
markedly closer to Confuciusornis than Sinornithosaurus, when I have found it 
difficult to see what in the Jehol dromaeosaurs separates them at the genus 
level, the separation of these taxa above the species probably represents 
problems 
with accurately determining the characters.

I also like that I'm hard pressed to see where I need to correct the 
Archaeopteryx skull restoration in DA, except for making the palatine more 
dinosaurian 
by making it tetraradiate. It is notable that the postorbital process of the 
jugal, contrary to studies that have claimed that it is located too 
posteriorly to articulate with the postorbital, points straight at the 
postorbital in 
the new skull. This is because the quadrate is strongly procumbent in this and 
all articulated skulls as noted in DA. Of course a complete postorbital is 
again not preserved and may have been absent, but other lateral temporal skull 
elements are  missing in this and other specimens so there is no way to be 
sure. 
At this point there is little reason to doubt that the skull of Archaeopteryx 
is highly or entirely theropodian, including the articulation between the 
quadrate and pterygoid (there being no solid evidence for a push-pull 
articulation 
and much against it). 

The Thermopolis specimen also verifies that Archaeopteryx lacked all the 
derived flight adaptations seen in sinornithosaurs (including microraptors) - 
large ossified sternal plates, ossified sternal ribs and uncinate processes, a 
strongly bowed metacarpal III (to better spread the primaries), a flattened 
finger II base that better supported primaries that were more elongated 
relative to 
the hand, ossified tendons on tail. The tendency of some to suggest some of 
these features will someday be revealed when a fully adult Archeopteryx is 
found is an ever longer stretch and should be considered moot unless such a 
specimen actually shows up. As far as I can tell archaeopterygians have no 
derived 
flight features not found in flying dromaeosuars. I have not checked in detail 
but I do not think these characters are being incorporated into cladograms. 
Their proper inclusion will only reinforce the more derived phylogenetic status 
of dromaeosaurs. Would be nice if someone would incorporate these features 
into their cladistic character lists - I'm not going to do it. 

At this point it is hard to see what would make Archaeopteryx more avian than 
other deinonychosaurs. There are the birdy teeth, but teeth are very plastic 
in evolutionary terms. Dromaeosaurs even lack the pterygoid process of the 
pterygoid still present in Archaeopteryx, which still has the old fashioned 
overlapping cervical ribs absent in the former. Maybe Archaeopteryx lacked the 
postorbital bar, but as far as I know it has not yet been found in any Jehol 
dromaeosaurs either, and some birds have it. 

My Archaeopteryx restorations dating back to the 80s were so dromaeosaur-like 
not, as some have sugggested, because I thought they were that way, but 
because the osteology shows that they were. 

The new specimens, combined with the analysis of the last couple of decades, 
plus the latest dromaeosaur and troodont specimens, make it clear that the 
basal deinonychosaur Archaeopteryx is not really the first bird. Instead it is 
one among many deinonychosaur dinosaurs that had well developed wings. 
Archaeopteryx is fast losing its status as the all important "urvogel" taxon 
around 
which centers our understanding of bird origins, which is logical since our 
data 
base is dramatically expanding. Archaeopteryx still stands as the first and 
most basal known flying dinosaur/member of the avian clade, but that is an 
accident of discovery that will change at some point. The vernacular term bird 
should probably be limited to avians that look like modern birds, particularly 
in 
having a very short bony tail (and that share the short tail with modern 
birds, so if oviraptorosaurs developed short tails independently they are not 
birds, if they inherited their tails from short tailed basal birds they too are 
birds), unless the bird revolved a long tail (not sure where this leaves 
Jeholornis). 

Basal dromaeosaurs were not only anatomically more derived than the earlier 
archaeopterygians, they were more derived fliers too. I hope this causes 
researchers to back off the recent tendency to restore the biplane dromaeosaurs 
as 
primitive protogliders simply because they had been plotting more basal than 
Archaeopteryx on cladograms. There is no reason to not conclude that flying 
dromaeosaurs were more advanced fliers than Archaeopteryx. As for the latter, 
as I 
explain in DA it is much too well adapted for flight in having a well 
developed wing with large muscle attachments and greater bone strength than the 
legs 
to be adapted for simple gliding. All you need for that is a means to stretch 
out some sort of airfoil. Some form of powered flight, however crude and 
limited, was very likely to have been present in archaeopterygians. Because 
winged 
dromaeosaurs have even better muscle attachments, more chest and arm strength, 
and bigger more firmly attached primaries, they must have been even better 
powered fliers. To argue otherwise does not sense make. In fact sinornithosaurs 
were getting close to confuciusornithids in this regard. 

Also severly damaged is the hypothesis that the flight features present in 
flightless deinonychosaurs and other derived theropods are preadaptations for 
flight. The arguments for folding arms, big sternal plates, pterosaur like 
tails 
and so forth having evolved for nonflight purposes and then being utilized 
for flight were always driven by cladistics rather than functional logic and 
are 
now obsolete unless we find Jurassic theropods that clearly evolved these 
things before flight appeared. 

It is now less likely that dromaeosaurs evolved flight independently as 
suggested by Makovicky et al. in their Nature Buitreraptor paper. But let's not 
get 
cladistically rigid in reverse. Maybe dromaeosaurs did independently evolve 
flight, and did so just once, or numerous times. Maybe they lost flight 
numerous times, or just once. Same with troodonts and so forth. Maybe 
archaeopterygians evolved flight independently. Maybe assorted deinonychosaurs 
evolved 
flight, lost it, evolved it again, and lost it again. Maybe basal dromaeosaurs 
evolved tandem wings independently. Or maybe this was a stage of flight that 
all 
Aves stem from. Maybe the young of the flightless dromaeosaurs had longer arms 
with wing and could fly, much as ora young often climb while the adults don't. 
As I noted in DA we have hardly any idea what these things were doing. One 
thing we do know is that the notion that flight evolved in a simple linear 
progression from the "Protoavis" to perigrine falcons has been demolished. All 
sorts 
of evolutionary experiments and reversals were probably going on. Although 
the possibility that flight was never lost in the bird-like dinosaurs is not 
entirely impossible, it is so improbable that it should be considered 
implausible 
unless convincing evidence to the contrary developes. In fact we can safely 
assume that flight was lost numerous times in deinonychosaurs, and probably 
other bird-like theropods as well. Although evolving flight may have been 
easier 
than is often thought, losing it is easier still. 

The Thermopolis specimen also shows something important about limb posture. 
Like all the other complete Archaeopteryx specimens, it is preserved on its 
side, flattened laterally. One leg is also in normal pose in that it projects 
ventrally from the hip, the other leg is clearly disarticulated dorsally. This 
consistent pattern is compatible with the cylinderical hip socket of 
Archaeopteryx which did not allow the legs to splay out strongly. Some of the 
Jehol 
dromaeosaurs are also preserved on their sides showing they could adopt an 
erect 
leg posture, but many if not most are preserved dorso-ventrally crushed with 
the 
legs splayed out to the sides. I have not seen a Jehol dromaeosaur with a 
truly cylinderical femoral head like those seen in the flightless 
velociraptorines, they are always somewhat more rounded in shape. This 
indicates that the 
winged dromaeosaurs could splay their legs out much more than normal in 
theropods, although not necessarily entirely flat. This makes sense since they 
had leg 
wings. I find attempts to explain how these hindwings were deployed without 
sprawling the legs highly dubious.    

G Paul