Re: _Parasaurolophus'_ crest and how much we can't deduce from it.

["Nicholas R. Longrich" <longrich@phoenix.Princeton.EDU>]

> Can someone offer me comment on this [perhaps silly] notion of mine, that 
> hadrosaur nostrils might at least in part have been sophisticated 
> water-retention devices?  In this group it seems awfully certain that 
> their primary function was as trombones, but my experience suggests that 
> many, if not most, signalling structures are elaborated from those in 
> which more physiological functions originally predominated.
> 
> Many thanks.
> 
> John C. McLoughlin

        if Parasaurlophus was trying to conserve water through 
condensation, the purpose of the nasal passages would be to increase 
surface area, right? But it's an incredibly inefficient way to do that. A 
much better way is to use thin, highly folded sheets of bone, if you want 
to increase surface areas (is this what the whole respiratory turbinate 
thing is about?). Parasaurolophus does have a lot of nasal surface area, 
but it's a really wasteful way to get it. I have no idea what the 
original purpose of duckbill nasals are, but in Parasaurolophus, the 
purpose of the crest is to increase the length, not surface area, of the 
nasal passages. 

        -nick L.