[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: live birth



 From: "Jeff J. Liston" <JLISTON@museum.gla.ac.uk>
 > Unless one of the eggs in your 
 > clutch is hatching, or contains identifiable chick remains (as 
 > opposed to embryonic tissue), you have no firm case for claiming a 
 > genus for your eggs.  It is very hard to say that egg X comes from dinosaur 
 > Y, simply because the same horizon, close 
 > at hand, contains remains (however abundant) of dinosaur Y.

Quite right.

 >  Some choose to allocate the largest of eggs to sauropods, on 
 > the basis that 'they were the biggest dinosaurs, so must have had the 
 > biggest eggs' - a maxim that is conspicuously absent from the rest of 
 > the animal kingdom.

To a point. With sauropods, however, the adults are so *very* large
that it seems clear the hatchlings had to be relatively large as well
for them to attain such sizes.

Also, there are seasons having to do with oxygen diffusion to
conclude that the largest known eggs are the largest *possible*
eggs, as you say below.

Thus, even if none of the eggs we now have really are sauropod
eggs, I would expect sauropod eggs to be similar in size.
 > 
 > But what I have problems with, regarding the sauropods, and even 
 > allowing that they may have laid the largest eggs that we currently 
 > know about, is the sheer practical problems of being a sauropod 
 > parent and NOT squishing your offspring that you have just expended 
 > so much genetic energy producing. 

This assumes that the parents were around when the eggs hatched.
In many animals the parents lay the eggs and then leave.  I see
no reason why the sauropods could not have done things this way.
[Well, then one does get the problem of how the juveniles got
attached to the herds, as is attested in the trackways].

swf@elsegundoca.attgis.com              sarima@netcom.com

The peace of God be with you.