The tail of Jeholornis...

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

...is not particularly dromaeosaurid-like.  Although the abstract and paper
call it dromaeosaurid-like, this is probably simply an
ornithologists-eye-view: it is actually a more generalized eumaniraptoran
tail (not terribly surprising, actually), more like a troodontid or
(perhaps, when we know the whole animal) _Rahonavis_, or an elongated (in
terms of number of vertebrae) _Archaeopteryx_.  The prezygapophyses (cranial
zygapophyses, for those who like  the Nomina Anatomica Avium) and chevrons
(haemal arches) ARE elongate relative to those of typical Cretaceous birds
and _Archaeopteryx_, but they are NOT the hyperelongate forms of
dromaeosaurids (and in fact the zygs aren't terribly long next to those on
the distal caudals of, for example, ornithomimids).

Like Mickey, I suspect that this critter and "Shenzhouraptor" are synonyms,
but (thankfully) are based on separate specimens.  (When I saw the photos of
the latter I had to do a doubletake and check the photos of _Jeholornis_.
They are in similar, but not identical, positions: see the position of the
right arm relative to the rib cage, for one aspect).

The development of the dorsal ischial process and the form of the manus do
suggest this is an Archie-_Rahonavis_ grade basal avialian; but for those
features, I would say it was simply Eumaniraptora incertae sedis.  Which, to
be fair, it might be: the phylogenetic analysis presented for it uses
Dromaeosaurids as the outgroup...

More stuff still to come out of Liaoning, though, and not all of it
eumaniraptoran!

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796