Re: Jeholornis prima discussion

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

David Marjanovic wrote-

> > There are twenty-two caudal vertebrae,
>
> There are 21 preserved caudal vertebrae. At least one (number 14) is
> missing, but who knows how many more? (Can't be many, judging from the
> relative sizes of the vertebrae, but one or two more should be possible,
> no?)

Technically, there are twenty complete vertebrae and parts of two more.
This is because of a crack in the slab.  However, when the slab containing
the distal tail and distal pes are moved so that they match up with the slab
containing the proximal tail and pes, the perfect amount of space to
complete the two partial vertebrae is formed.  Making space for more caudal
vertebrae would offset the distal pes.

> Martin accepts that it's a bird: http://www.msnbc.com/news/784936.asp.

Interesting.  I note no ABSRD viewpoints have been associated with this
fossil.  Could that view be dead at last?

> > Judging by some quick comparisons, it's more derived than Archaeopteryx
> based on the [...] less than eight caudals with transverse processes,
>
> More derived, certainly, but not more birdlike. Like in *Nomingia*, in
birds
> there are transverse processes even in the pygostyle.

I disagree, though researching the topic killed one of my
Yandangornis+Jeholornis characters.  Both Iberomesornis and Sinornis only
have four caudals with transverse processes.  They are absent from free
caudals five and six, as well as any vertebrae incorporated into the
pygostyle (Sereno, 2000).  From what I can tell, Confuciusornis has five
caudals with transverse processes (judging by GMV-2153 and 2131), which
leaves two free caudals without transverse processes (as seen in GMV-2132).

> > [...] scapulacoracoid joint mobile,
>
> Really?

It's coded that way- character 83.  You'll note dromaeosaurids,
Archaeopteryx, Confuciusornis and Sapeornis are not, while Rahonavis and
ornithothoracines are.

> -- It's really hard to argue that the last tail vertebra is a pygostyle.
It
> looks a lot like the last tail vertebra of *Archaeopteryx*. So either it
is
> closer to *Rahonavis* than to Avebrevicauda (that term was needed... I
thank
> HP Gregory Paul for introducing it in DA), or the pygostyles of *Nomingia*
> and Avebrevicauda are not homologous. A very big photo of that vertebra,
in
> absence of the specimen itself plus a binocular, would be needed to
clarify
> this. (Same for *Caudipteryx*.)

I think it impossible to argue the last caudal is a pygostyle in Jeholornis.
Unless you want to start arguing every coelurosaurs' last vertebra is one.
Why would having Jeholornis closer to Rahonavis than avebrevicaudans make
its lack of a pygostyle any more parsimonious.  The condition in Rahonavis
is unknown.  I think you should just give up trying to call the last caudals
of Caudipteryx and Jeholornis pygostyles, as you have no morphological
features to justify it and don't doubt the identity of the last vertebrae of
other taxa (eg. Archaeopteryx).  You're just trying to fit data to the
model, like ABSRDists giving Caudipteryx a "quasipygostyle".

> _Might_ argue for allying it with *Rahonavis* but not *Yandangornis*. Hm.
> -- If it's closer to Avebrevicauda than to *Rahonavis*, then it represents
> the third time a scapulocoracoid joint evolved among theropods -- while
> pterosaurs never did it.
> -- News to me that Shenzhou means China. I only know Zhongguo ( = middle
> country). But that's obviously just me, lacking knowledge of Chinese terms
> for Chinese history. :-)

It would be sad if true, because it would be redundant with the species name
sinensis.  "Chinese snatcher from China".  Yay.

> -- Is the hallux of *Shenzhouraptor* really unreversed? It looks reversed
to
> me, and this doesn't go away when I enlarge the image to 400 % in
Microsoft
> Photo Editor (that's the best compromise between the effects of magnifying
> the image and magnifying the pixels; it also allows one to tell tail and
leg
> apart and to see that the tail really starts at the sacrum and is not a
> break behind the leg).

Supposedly.  That's how Altavista translated
http://www.cas.ac.cn/shownews.asp?id=200207230003 -
"But in other some characteristics, the Chinese divine land bird actually
demonstrates the strong primitive color, <snip> the foot çäè liked other
models the beastly foot class dinosaur such does not have the reverse, after
the foot fingernail still to face, indicated its toe does not have " to
grasps " or " grasps grasps " function."
And http://english.peopledaily.com.cn/200207/23/eng20020723_100179.shtml
said-
"Its first toes have not yet turned inwards like the archaeopteryx ...."
The hallux looks unreversed to me in the photo, but its very pixellated at
that magnification of course.

> -- Is *Shenzhouraptor* validly published? If so, does it have priority
over
> *Jeholornis*?

Supposedly published, but the Geological Bulletin of China website has not
updated with volume 21, number 5.
http://zgdizhi.periodicals.net.cn/default.html shows number 5 up, but it's
the same content as number 4 at the moment.

Mickey Mortimer