Re: Re(2): T. rex eggs and brooding

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

Lars Bergquist wrote: 

>
>There are a number of living reptiles, including the crocs, and also
>some species of birds, that make a nice compost and bury the eggs
>in them. The heat of decomposition keeps the eggs warm. Mom, and
>sometimes Pop too, hang around to defend the site and to regulate the
>temperature by scratching away or piling up more material.
>
>The dinos, of course, knew no physics or microbiology, had no
>thermometers, and had never heard of either Mr. Fahrenheit or
>Mr. Celsius. But neither have the crocodilians  so a dino would
>not have to be smarter than a croc to pull off this trick. Natural
>selection does it all, by courtesy of Mr. Darwin.



You are correct that the crocodiles and megaopode birds build vegetation 
mounds for eggs.  However, crocs also lay eggs in holes and 
bury them as well.  With crocs that do build a mound, they do not modify 
the mounds to control nest temperatures.  Male megaopode birds check the 
inside temperature by projecting their beak into the mound.  And, as you 
point out, do move vegetation to regulate nest temperatures.  It is also 
important to note that not all crocs guard their nests, and this can 
even vary among individuals of the same species.  Alligators have been 
observed laying next to their nest while raccoons raided the eggs.