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Re: dracrorex and National Geographic



HI:
 Does anyone have a PDF of the Horner paper mentioned here?



On Mon, 26 Nov 2007, Denver Fowler wrote:

> I just saw this month's National Geographic magazine. Isn't it a tad 
> embarrassing to see "Dracorex hogswartsia" on the cover, and in the article?: 
> when "Dracorex" was recently outed (along with "Stygiomoloch") as growth 
> stages of Pachycephalosaurus (Horner et al, SVP2007): not even mentioned in 
> the article. I find it pretty surprising that National Geographic would sit 
> so behind the times like this.
>
> ----------------------------------
> Denver Fowler
> df9465@yahoo.co.uk
> Work:
> http://www.museumoftherockies.org
>
> Fieldwork  pictures NM 2002-4 & China 06:
> http://www.statemuseumpa.org/notes05.htm
> http://www.wald.heim.at/urwald/540645/JH-Projekte/China_04-2006/chinaset.htm
>
> TV Work:
> http://www.impossiblepictures.co.uk
> http://www.bbc.co.uk/dna/h2g2/A664661
>
> Art:
> http://dino.lm.com/artists/display.php?name=df9465
> -----------------------------------
>
> ----- Original Message ----
> From: Sarah Werning <swerning@gmail.com>
> To: david.marjanovic@gmx.at; dinosaur@usc.edu
> Sent: Monday, 26 November, 2007 2:29:33 PM
> Subject: Re: Marsupial forelimbs... or rather hindlimbs
>
> Well, it'll be nice to see this paper when it comes out. Obviously, to
> speak about a heterochrony you need to compare ontogenies across
> phylogeny, and though there are studies that have looked at this
> question (and similar ones) for these groups, this is certainly the
> largest placental-marsupial developmental comparison to date.
>
> I don't know that this is especially novel in terms of thinking,
> though; there are papers that have suggested deceleration of hindlimbs
> is what is going on in marsupials (although the majority do suggest it
> is acceleration of forelimbs). It will be interesting to see their
> methods: do they hold timing of development of hindlimbs constant
> relative to a third event, such as brain development? Or constant to
> time/developmental stage? A lot of the current literature holds brain
> development constant and compares limb or facial development relative
> to that. I'm especially curious about which outgroups they used and
> what's going on in them.
>
> In terms of comparing forelimb to brain development, there is a large
> body of literature that suggests that marsupials are indeed developing
> their forelimbs earlier than placentals in both absolute and relative
> terms. In several cases (e.g., Monodelphis, Dasyurus) you get
> development and ossification of the facial and forelimb bones (and
> significant development of their associated muscles) while the brain
> is still undifferentiated neuroepithelium (and while big chunks of the
> rest of the body is undifferentiated mesenchyme). The
> forelimb-hindlimb timing is interesting, but think the story with the
> timing of brain/braincase and limbs is more interesting.
>
> For some really cool research by someone who completely gets
> heterochrony, and who works on limb and craniofacial development in
> marsupials and placentals, check out Kathleen K Smith's website:
>
> http://www.biology.duke.edu/kksmithlab/
>
> Most of her papers are available as free pdf's.
>
> Sarah
>
>

-- 

Ian Paulsen
Bainbridge Island, WA, USA
A.K.A.: "Birdbooker"
"Rallidae all the way!"