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Re: [dinosaur] Blocked post about new study finding common ancestry in scales, feathers, hair




Ben Creisler
bcreisler@gmail.com



OK... It got through. I'll try the original citation with abstract:


Nicolas Di-Poï and Michel C. Milinkovitch (2016)
The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appendages in amniotes.
Science Advances  2(6): e1600708
DOI: 10.1126/sciadv.1600708
http://advances.sciencemag.org/content/2/6/e1600708.abstract

Most mammals, birds, and reptiles are readily recognized by their hairs, feathers, and scales, respectively. However, the lack of fossil intermediate forms between scales and hairs and substantial differences in their morphogenesis and protein composition have fueled the controversy pertaining to their potential common ancestry for decades. Central to this debate is the apparent lack of an "anatomical placode" (that is, a local epidermal thickening characteristic of feathers' and hairs' early morphogenesis) in reptile scale development. Hence, scenarios have been proposed for the independent development of the anatomical placode in birds and mammals and parallel co-option of similar signaling pathways for their morphogenesis. Using histological and molecular techniques on developmental series of crocodiles and snakes, as well as of unique wild-type and EDA (ectodysplasin A)–deficient scaleless mutant lizards, we show for the first time that reptiles, including crocodiles and squamates, develop all the characteristics of an anatomical placode: columnar cells with reduced proliferation rate, as well as canonical spatial _expression_ of placode and underlying dermal molecular markers. These results reveal a new evolutionary scenario where hairs, feathers, and scales of extant species are homologous structures inherited, with modification, from their shared reptilian ancestor's skin appendages already characterized by an anatomical placode and associated signaling molecules.


On Fri, Jun 24, 2016 at 1:22 PM, Ben Creisler <bcreisler@gmail.com> wrote:

Ben Creisler
bcreisler@gmail.com


Not a good day...

First, I sent a news item about the privately owned pterosaur without reviewing a misleading comment. My intended point was supposed to be that it was studied at a time when its future curated status was not determined--it could have been sold into private hands after being described. Now it's been donated to a museum, as explained in the news story, which is good news. 

I have also tried repeatedly to a post a new paper and related news stories to the DML. None appear to have gotten through and I have no clue about the problem. Here are the links at least, with an edit in the title, and without the abstract:

In open access;


Nicolas Di-Poï and Michel C. Milinkovitch (2016)
The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appen dages in amniotes.
Science Advances  2(6): e1600708
DOI: 10.1126/sciadv.1600708

News: