Re: Sexual Dimorphism in Maiasaura (was seasonal day care)

["Rob Gay" <rob_redwing@hotmail.com>]

> That is odd.  Didn't Horner find a bonebed with some 10,000 Maiasaura 
> individuals??  You'd think that there would be a decent amount of skull 
> material available there (I mean, Dodson used on 36 skulls in his analysis, 
> Raath only 30 Syntarsus specimens, and Larson only a handful of Tyrannosaur 
> specimens).<
Exactly, this is why I found his statement odd. But, when I think about it, 
I have only seen one complete adult Maiasaura skull. It is very odd that 
such a large assemblage would be biased against skulls.

> Perhaps Horner was just being cautious when you asked him about sexual 
> dimorphism.  He's a very cautious guy, and maybe he believes that the 
> number of skulls that he has (or has seen) isn't a large enough number to 
> 'correctly' study dimorphism.  Maybe he wants a larger sample, and isn't 
> content with, say, only 100 skulls<
Also quite possible.

> Either way, I predict that in the future a good amount of Maiasaura skulls 
> will be found.<
I hope so! The more material, the better, I say, even with such an otherwise 
large sample size as Maiasaura. I think that between Coelophysis and 
Maiasaura we are presented with an opportunity to examine a large sample of 
individuals that formed one single population. If we were going to figure 
out if sexual dimorphism existed in any dinosaur, these two would be out 
best bet.
Peace,
Rob

Student of Geology
Northern Arizona University
P.O. Box 20840
Flagstaff, Az. 86011
AIM: TarryAGoat
"A _Coelophysis_ with feathers?"

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