Re: Ptero embryo

["Simon M. Clabby" <dinowight@yahoo.co.uk>]

Unless things have changed, the Full-text version
usually has a larger jpeg version of any images

 --- David Marjanovic <david.marjanovic@gmx.at> wrote:
> ----- Original Message -----
> From: "David Peters" <davidrpeters@earthlink.net>
> Sent: Thursday, June 10, 2004 1:48 PM
> 
> > In the meantime, if anyone can send me a pdf
> > [or better yet, I hi-rez jpeg], I'd appreciate it,
> just in case I run
> > into some red tape.
> 
> Very unlikely, because the picture in the pdf has
> very low resolution (as,
> grrr, usual for Nature). There even is no way to see
> the papillar surface
> ornamentation on the eggshell fragment that is
> mentioned in the text and
> indicated in the close-up photo!!!
> 
> > 1. the embryo is ossified
> 
> I hope so.
> 
> > 4. the sclerotic ring appears to be relatively
> large in relation to the
> > skull length
> 
> It must be -- except if the adults had
> _dramatically_ better vision than the
> babies. Eyes have strong negative allometry; small
> animals have
> proportionally bigger eyes than large ones.
> 
> > 5. if the embryo is a baby Haopterus, the rostrum
> is much shorter and
> > rounder than the neonate Haopterus I found [see
> pterosaurinfo.com]
> 
> It must be -- the brain has strong negative
> allometry, too. It gets totally
> bloated very early in ontogeny and then grows very
> slowly. I'm sure you've
> seen drawings or photos of _any_ vertebrate embryo!
> 
> > In addition, the record of Wang and Zhou is not
> good with regard to
> > identifying pterosaurs and parts of pterosaurs.
> 
> Ad hominem argument. Pseudoscientific.
> 
> > I have a working hypothesis that indicates
> > the Chinese embryo may not be an embryo at all,
> 
> Then what is it doing inside an egg?
> 
> > VIVIPARITY AND MATERNAL CARE IN PTEROSAURS AND
> OTHER HIGHER
> > PROLACERTIFORMS
> 
> "Say never higher or lower"
> -- Charles Darwin, written on the margin of a book
> :-)
> 
> > Recent research has found
> 
> It's not good to imply that 5 or 10 researchers all
> over the world have
> found them when this isn't the case. Why not "I have
> recently found"?
> 
> > these unossified offspring
> 
> Are you aware what this means? That they were all
> terminally rachitic, and
> _suffering_ from it. Unable to support their own
> weight. Much like a
> stranded whale.
> 
> > In <i>Cosesaurus</i> a ruptured sac is visible
> within the mother's torso,
> 
> If such a thing is preserved, then where are all the
> inner organs? Why
> doesn't it _at least_ look like *Scipionyx*?
> 
> > a half-size juvenile
> 
> An unossified juvenile half the size of an adult?
> What have I misunderstood
> here?
> 
> > Relatively short snouts and large orbits place
> these tiny adults close
> > to <i>Scaphognathus</i> and <i>Dorygnathus</i> in
> cladistic analysis.
> 
> These features are classical features of juveniles,
> see above.
> 
> > Pterosaur offspring do not have proportionately
> larger eyes.
> 
> See above for why this is _funky_.
> 
> > The rostrum may be shorter.
> 
> I hope so.
> 
> > At birth the wing finger may
> > be relatively longer than that of the parent
> 
> While the animal is unable to fly???
> 
> > The data shows that no
> > more than two juveniles and two embryos are
> present, except in breeding
> > grounds where the matrix may be littered with
> abandoned babies.
> 
> Why "abandonded"?
> 
> > As in bats, offspring clung to the mother,
> apparently beneath
> > her and oriented posteriorly.
> 
> Not obvious from those of your tracings that I've
> seen.
> 
> > Delayed ossification facilitated the
> > development of extremely thin-walled hollow bones.
> 
> No, the development of severe rachitis. Pneumatic
> bones are formed by air
> sacs _destroying present bone_, not by bone growing
> as a tube.
>  

=====
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