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Re: Huevos Dinosaurios



admittedly the drain of calcium on a bird (with a very low
egg-size-to-parent-size ratio) would seem to be far greater than that
which would happen with most dinosaurs (with anything larger than 200
lbs having very high egg-size-to-parent-size ratios).  

-Betty

William Gibson Parker wrote:
> 
> Calcium is not only important in animals as a structural component of
> bone, it is also important for blood coagulation, muscle contraction,
> myocardial function and of course the manufacturing of eggshell.  Egg
> laying animals need supplements of calcium not only for the above
> functions but also to keep their eggs strong and also for the animal to be
> able to lay the egg safely.  I'm curious on how the dinosaurs would have
> supplemented their diet with calcium.  The calcium for the eggshells must
> come from stores in the body, chickens for example store this calcium in
> extensions of bone.  After laying, these stores must then be replenished.
> Of course chickens lay many more eggs than dinosaurs would have, and would
> need to replenish this supply faster and more often.  Dinosaurs, I
> imagine, would also need to receive calcium supplements also to insure
> healthy egg laying and to decrease the risk of "egg-binding".  Where would
> this calcium come from?  Are ferns and gingkos a good source of calcium?
> Maybe they would need to do as chickens do and eat the occasional oyster
> shell or pieces of limestone (origin of gastroliths?).
> What about the carnivores?  There is a suspected case of gout in a T-rex
> fossil.  How would this animal been able to reproduce with such low
> amounts of calcium in the body.  Of course maybe this individual was
> older, or male.  If this was a common problem with T-rex it would seem to
> cause a terrible effect on the egg-laying capabilities of the animal.  Of
> course these animals did reproduce so the problem must have been overcome
> in most of the animals and low-calcium must not have been a problem.  As
> such it would seem that most dinosaurs were getting minerals in their diet
> from somewhere (calcareous dirt?)  Does anyone have any comment on this
> subject?
>  -Bill Parker
> Northern Arizona University