Re: Pterosaur embryo and soft-shelled eggs

[Jeff Hecht <jeff@jeffhecht.com>]

At 6:07 PM -0700 6/9/04, Christopher Collinson wrote:
> We're talking soft-shelled as in a crocodile egg, as apposed to hard-shelled
> like a bird's right?


Soft as in pliable, rather than brittle, like bird or dinosaur eggs. 
Soft-shelled eggs wouldn't allow brooding (in the sense of the animal 
sitting on top of the eggs), but they could deform as they were laid. 
-- Jeff Hecht

> Cheers,
> Christopher
>
> ----- Original Message -----
> From: "Jeff Hecht" <jeff@jeffhecht.com>
> To: <qilongia@yahoo.com>; <dinosaur@usc.edu>
> Cc: <john.bass@ntlworld.com>
> Sent: Wednesday, June 09, 2004 5:50 PM
> Subject: Pterosaur embryo and soft-shelled eggs
>
>
> >  At 5:03 PM -0700 6/9/04, Jaime A. Headden wrote:
> >  >
> >  >   Actually, most of the Lower Cretaceous Liaoning/Liaoxi/Nei Mongol
> >  >fossils are preserved much as in the microraptor specimens, in that bone
> >  >is crushed, diameters distorted, longitudinal and sometimes transverse
> and
> >  >diagonal cracks are present, shapes deformed, and skulls tending to be
> >  >"shattered" in nature with some disarticulation (the holotypes of
> >  >*Sapeornis* and *Microraptor zhaoianus* are disarticulated, the former
> >  >more than the latter). There are very few "complete" skulls, and pelvises
> >  >are almost always disarticulated to some degree, limbs broken and
> >  >shattered or digits distorted.
> >
> >  WHich raises an interesting point about the pterosaur embryo just
> >  reported from the Yixian deposits. Like most of the other fossils
> >  from those deposits, it's squashed very flat, with some bones
> >  apparently disarticulated as a result. (I haven't seen the fossil,
> >  just a PDF of the Nature paper.) That suggests to Dave Unwin (whom I
> >  interviewed for a New Scientist story to appear in this week's issue)
> >  that pterosaur eggs were soft-shelled, so they could be squashed flat
> >  without breaking. He thought hard-shelled eggs would be shattered.
> >
> >  So... have dinosaur eggs been found in the Yixian deposits? If so,
> >  are they shattered of flattened?
> >
> >  --
> >  Jeff Hecht,    science and technology writer
> >  Boston Correspondent, New Scientist magazine
> >  Contributing Editor        Laser Focus World
> >  525 Auburn St.,   Auburndale, MA 02466   USA
> >  V 617-965-3834  F 617-332-4760  e-mail jeff@jeffhecht.com
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