Re: Avians and their Kin

["David Marjanovic" <david.marjanovic@gmx.at>]

> > > The earliest known articulated maniraptoran theropods, _Microraptor_
and
> > > _Sinornithosaurus_ (right?),
> >
> > Excluding *Archaeopteryx*, isn't *Deinonychus* earlier? (And is it
> > articulated?)
>
> No, _Deinonychus_ (Aptian-Albian, late early Cretaceous, approximately 110
mya)
> does not appear earlier than the Liaoning species (estimated at about
120-125
> mya).

Oh, sorry, I forgot that. So those from Liaoning are the earliest ones.

> > > are also apparently the most anatomically
> > > bird-like dinosaurs (undescribed Liaoning specimens notwithstanding).
> >
> > IMHO they are the most *Archaeopteryx*-like ones, not the most bird-like
> > ones, and even that only because of symplesiomorphies. This of course
> > depends on one's phylogenetic hypotheses.
>
> If the Liaoning "dromaeosaurs" (if such they are)

I use this term for {*Dromaeosaurus* > *Archaeopteryx*} as long as no formal
one exists*. Dromaeosauridae is used that way in the description of
*Sinornithosaurus*, but that's wrong because Dromaeosauridae has a
node-based definition and *Sinornithosaurus* (and *Microraptor*) are
apparently outside that node.

* Just for the sake of parroting: We need to be able to name as many
"intermediate taxa" as we need, even though this may be circular. :-)

> are not the most bird-like
> putative non-avian maniraptorans, then which non-avian maniraptorans are
more
> bird-like than them?

"Non-avian" becomes difficult to use in my phylogeny... if Aves is
{*Archaeopteryx* + *Passer*}, then IMHO _everything_ in the cladograms below
is avian except the root. HP Mickey Mortimer has found that an earlier
version of my matrix produces

+--Alvarezsauridae
`--+--Avimimus
     `--Pygostylia

next to assorted enigmosaurs which were totally unresolved because I hadn't
included any oviraptorosaurian or "enigmosaurian" synapomorphies in that
matrix. My prejudice at the moment is

--+--+--Dromaeosauridae etc.
    |    `--+--*Archaeopteryx*
    |         `--*Rahonavis*
    `--+--+--Tyrannosauroidea
         |     `--+--Ornithomimosauria
         |          `--Troodontidae
         `--+--"Enigmosauria"
              `--+--Alvarezsauridae
                   `--+--*Avimimus*
                        `--+--*Yandangornis*
                             `--Pygostylia

I have yet to find the pelvis of an early bird in dorsal view and to have a
look at the proximal end of the metatarsus of *Confuciusornis*; apparently
all fossil birds are badly preserved in the pelvic region and/or in ventral
view anyway and have poorly preserved and/or fused proximal metatarsi. Or
can someone help me? :-) All I know at present is that

- theropods basally have rather parallel ilia with few space in between
(state 0 of character 6 in Matrix 3.0 and 3.1);
- *Archaeopteryx* and dromaeosaurs have rather parallel ilia with lots of
space in between (the sacral transverse processes are longer than the caudal
and dorsal ones) (state 1);
- at least Neornithes and with high probability *Avimimus* (which is a bit
fragmentary) have "sigmoid" ilia that fuse with the neural spines cranially
but are far apart caudally. *Yandangornis* is in ventral view and not well
enough preserved there.
- *Yandangornis* and *Iberomesornis* have mtIII that are expanded at the
very proximal end, the highly fused *Dinornis* tarsometatarsus that lies in
the Institute of Paleontology here (exhibited in, er, non-plantar view)
_could_ have the condition, while nothing else I know (including
*Rahonavis*, oviraptorosaurs, dromaeosaurids, and *Archaeopteryx*) has the
condition. If basal pygostylians don't have the condition I can't code
Pygostylia as having it, and it becomes a useless autapomorphy of
*Yandangornis*.

Fortunately a very good specimen of *Confuciusornis* is exhibited in the
museum here. I can probably visit it on Monday.