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Re: More tyrant Q & A's



Perhaps I'm missing something.  

It seems to me that suggesting the female of a genus like _Tyrannosaurus_
would be larger in general is not well-founded.  I recognize the chevron
dimorphism and feel that this is a good character, but how widely has this
been surveyed or may it be surveyed?  Skeletons are incomplete at best and
one little chevron is liable to be displaced.  

More often, I see the bird analogy, and I agree that birds are good
analogies for dinosaurs in many cases, but maybe not here.  

Consider why a female bird is larger--to carry eggs.  Many features of birds
may find their origins in weight reduction.  The single operational ovary is
one of these.  Male birds don't have to worry about carrying eggs so they
can be smaller whereas female birds need the extra size.  Also, birds often
copulate on the wing without the aid of external genitalia.  When copulation
is land-based, external genitalia are implemented and the size dimorphism is
less pronounced.  When you are terrestrial it seems better for the male to
be larger to make copulation less cumbersome.  

Of course, there are exceptions and like I said, maybe I'm missing
something.  

Jack