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Re: Did We Get Dinosaurs' Noses Wrong? OPINION (Stanford)



Some opinions from both sides:

I (On Small Nostrils):  Conversely, you could also
argue that smaller nostrils would _prevent_ too much
blood and guts from flowing in, and permit easier,
higher velocity ejection of those stuff when the
animal snorts them out.
(http://www.nsf.gov/od/lpa/news/press/01/trex.htm)

II (On Large Nostrils):  What about present day
carnivores?  The big cats appear to all have fairly
large nostrils 
(http://www.bengaltigers.com/bigcats/pictures/images/pic032.jpg,
http://www.bengaltigers.com/bigcats/pictures2/images/pic041.jpg).
 Somewhat with dogs . . . 

III (Confusion, and More Questions):  but, all these
mammals have their nostrils at the very tip of the
snout as well!  And they all get messy during attack
and carcass grubbing.  The same for the only
comparable reptile, Komodo dragons
(http://www.amazilia.net/images/Herps/Lizard/komodo6.JPG).
 

  So what's more important, preventing blood and guts
flooding the nasal passage, or capacity for faster
respiration/heat exchange/smelling/vocalization?  Is
there a threshold of nostril size (if all carnivores
have the nostril-at-tip position) for maximum function
and minimum dirtying?  What are other pros/cons of
small or large nostrils?




Thanks,

Ben Landis
Student of Zoology
UC Davis

--- Ray Stanford <dinotracker@earthlink.net> wrote:
>     In the National Science Foundation's news
> release (Link kindly provided
> by Dan Varner.  See below.), we see the "new" T. rex
> with tiny nostrils
> right up front.  It seems to me that if the nostrils
> were actually that far
> forward (and they may have been), they surely might
> have been substantially
> larger than shown in the illustration.  Why? Because
> whether this animal
> were biting into living animals or just into
> carcasses, it seems to me that
> such tiny nostrils placed that far forward might
> easily have become filled
> with blood (or something else, like intestinal
> contents) or even gradually
> closed when air passing across blood in the nostrils
> clots it.
> 
>     I may be way out in left field thinking that
> way, but would be
> interested in reading comments on this idea by list
> members.
> 
>     Ray Stanford

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