Re: Ptero embryo

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

----- 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.