RE: weird jurassic dinobird with very weird feathers

["Jaime A. Headden" <qilongia@yahoo.com>]

  I should have noted, however, that what I saw as a furcula, in the line 
drawing, corresponds to a rib. Oops. No such element is preserved. Contrary to 
paravians, the coracoid of the near preserved is preserved inline with the 
scapula. Mickey has argued previously that the coracoid shoudl articulate, as 
birds do, into a tight angle, and likens the element to *Bambiraptor* in hsi 
last post. This element appears to be preserved such that the articular glenoid 
is oriented ventrally, rather than posteriorly or laterally. The same element 
of the other side is disarticulated from the scapula. This seems at odds with 
previous arguments that the shoulder is "incipiently" avian.

  Some other observations:

  The jugal has a strongly posteriorly ascending process, and may very well 
have lacked a contact with the postorbital, which is otherwise poorly preserved 
on both slabs. However, what may be the ascending process of the jugal appears 
to be expanded distally. This suggests a closed postorbital bar.

  The posterior process of the jugal, the quadratojugal ramus, appears to be 
forked, and may preserve portions of an element of the quadratjugal itself.

  The quadrate (~12.4mm) is about as high as the orbit is tall (~14mm), which 
is far from the derived condition in paravians in which the vertical height of 
the quadrate is reduced relative to the orbital height or overall cranial 
height.

  The mandible in aspect is as similar to *Confuciusornis* as said avian is to 
an egret. The mandible is strongly downcurved, with prodigious dental roots (at 
least 60%+ of the teeth as preserved are above the root/crown margin and the 
mandibular edge); there is no invasive process of the surangular into the 
external mandibular fenestra, and the fenestra is roughly evenly ovate rather 
than oblate (expanded more to one said than the other, as an egg) in shape; 
there does not appear to be a large surangular foramen, and there does appear 
to be a long, but not deep and short retroarticular process, although the 
elements appear broken.

  There is a large lachrymal foramen.

  The femoral caput does not appear to be elevated above the trochanteric body, 
and seems to be subquadrangular with a semi-spherical quality to the 
medial-most extent.

  There are no pennate feathers. At least even basal dromaeosaurs, 
oviraptorosaurs, and probably troodontids had true feathers. This places the 
taxon at least in either 1) a degenerate state, in which case it should lack 
features associated with a flight apparatus a la therizinosauroids, or 2) it is 
not as close to birds as the authors of the paper positioned it. The matrix 
would be better suited to looking at their codings.

  The distal ends of the scapula are expanded. This was proposed for 
*Scansoriopteryx*, as it was argued the element found on the slab was the 
distal end, but others have argued it as the proximal element. A broad distal 
expansion is also not in keeping with this taxon's placement closer to birds 
than to deinonychosaurians, which produced reduced distal expansions to none at 
all, as in Avialae.

  I am not sure why an animal that is so closely aligned in morphology to other 
"scansoriopterygids" would have a reduce tail, as if the extreme modification 
would be coincident with pelvic modifications due to anteriorized center of 
gravity; such do not appear to occur, and the dorsal column reminds me of 
compsognathids in being long and low, much longer at least than the tibia by 
about 20%. Comparatively, *Confuciusornis* dorsal/tibial lengths are close to 
equal, *Gallimimus* is roughly 10% longer in the dorsum, and *Velociraptor* 
appears to be about 15% or so. (I'm guestimating from images of Scott Hartman's 
and Greg Paul's skeletals here.) The body adaptations do not agree with a short 
tail, and given the intactness of the distal segment and the disarticulated 
aspect of the proximal, I would strongly urge a disconnect, and therefore lack 
of confidence as to the tail's length overall.

  The ilium appears to have a broad cuppedicus shelf, and MAY have a 
supracetabular crest, but that could be an artifact of the image. It (the 
supracetabular crest) may be the element that is overlying the proximal pubis.

  It is entirely possible the manual phalanges represent portions of digits 1 
and 3, not 1 and 2, since the second manual ungual in *Epidendrosaurus* is, 
like *Confuciusornis* of all things, smaller than the other two. The unguals in 
*Scansoriopteryx* appear of equal size.

  Cheers,

Jaime A. Headden

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