Re: eggs with thin shells

[Crpntr@ix.netcom.com (Kenneth Carpenter)]

Neil Clark wrote: 


>Through compaction the calcite shell can be thinned in the direction of 
>maximum compaction resulting in the egg being thinner on the top 
>and bottom and thicker on the sides.
>->0<- (egg seen sideways on as I can't find the keys to do it the right 
>way - arrows show direction of compaction and the thinned part of the 
>egg shell).

Sorry, no the calcite of the shell would not thin through compaction, it 
would however, telescope in.  It is also important to note that shell 
thickness is not even all over the egg.  It is usually thickest on the 
lower pole or bottom, medium on the sides, and thinnest on top to allow 
the hatchling out (the French refer to the thin top as the "hatching 
window", a term I do not care for).


Kenneth Carpenter

>
>As an extra, the bun-shaped eggs also seem to have a 'ratite' 
>structure to them yet they have been decribed as sauropod 
>(herbivore) or ornithopod (also herbivore).
>
>Neil
>
>
>Neil Clark
>Curator of Palaeontology
>Hunterian Museum
>University of Glasgow
>email: NCLARK@museum.gla.ac.uk
>
>Mountains are found in erogenous zones.
>(Geological Howlers - ed. WDI Rolfe)
>
>