Re: Yixian Dating Again

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

----- Original Message -----
From: "Jaime A. Headden" <qilongia@yahoo.com>

> >   Yes. I beleive Lo et al., used a whole congolomerate, whereas other
> > studies used single-grain sampling. However, U/Pb sampling and Ar/Ar
> > sampling also provide similar _and_ dissimilar results.

I see.

> >   You know, it used to be Yünnan, then you transcribe Yúnnán, I wonder
> > why not just use simplified syllabaric approximations? Chinese lacks
> > diacritics.

Actually, the Pinyin transcriptions has diacritics for the tones. I use them
sporadically in my e-mails because only the 2nd tone (´, pronounced "?") and
the 4th (`, pronounced "!") are available on my keyboard and have a
reasonable chance of arriving correctly. The ü dots are unnecessary in this
case because only ü and not u can occur after y (and x, j, q); only in nü
and lü need they be written. Lü Junchang is an example for both cases.

> > <Well, the tail is from a *Microraptor*, isn't it? There's a second
> > anurognathid from the Yixian Fm, *Jeholopterus* from Inner Mongolia. The
> > authors
> >
> > Wang Xiaolin, Zhou Zhonghe, Zhang Fucheng & Xu Xing: A nearly completely
> > articulated rhamphorhynchoid pterosaur with exceptionally well-preserved
> > wing membranes and "hairs" from Inner Mongolia, northeast China, Chinese
> > Science Bulletin 47(3), 226 -- 232 (February 2002)>
> >
> >   I have this ... it's not an anurognathid. Not close.

Just from looking at the drawings, it can only have a short tail, so it can
only be a pterodactyloid or an anurognathid among known pterosaurs, and it
has long 5th toes, so it can't be a pterodactyloid. It has a short, round
skull (whether it's high, too, is obscured by crushing) that is positive
evidence for anurognathid relationships. Many more arguments are listed in
the text.

> > <AFAIK no J angiosperm pollen are known, right?>
> >
> >   There is plenty of pollen from the Jurassic and Cretaceous that were
> > offered as earliest angiosperms, but most have beein either disproven,
> > or the rest subsumed to ambiguity or bad preservation.
> > This is true of all the Jurassic palynomoprh studies.

I see.

> > <Would you say the teeth from Guimarota, not to mention the MJ ones from
> > England, look like known troodontids? (I can't tell.)>
> >
> >   I have not seen these teeth, and have been very interested in them for
a
> > while... just no opportunity to get the book, or find the papers on many
> > isolated teeth in discussion. I tend to look at morphotypes more than
> > anything that might be taxonomically important. But I am interested in
> > these Guimarota teeth in specific. All of them ... lol.

www.pfeil-verlag.de/07pala/e2_80.html. It's pretty expensive (80 US$... but
that probably includes shipping, 61.35 euros is quite a bit less, though
still enough). But the superb quality of the photos is about worth it.
Scroll down to the bottom of the page to order a free review copy. I hope my
review in the Dinosaur Society Quarterly has been published or will be
sometime... said society is deep in debts and will sometime move to a
website.
        There are compsognathid, other basal coelurosaur, troodontid,
dromaeosaurine, velociraptorine, tyrannosauroid and "cf. *Archaeopteryx*
teeth. Not to mention the pterosaur teeth, sample page here
www.pfeil-verlag.de/07pala/abb/2_80d5.pdf, and the non-theropod dino teeth
www.pfeil-verlag.de/07pala/abb/2_80d4.pdf.