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

Re: nostrils?



>When would they have moved?
>Between dromosaurids and aves? After?
>Why?  To keep bugs from going up the nose during flight?
>Is this also seen in pterosaurs?
>It seems to be seen in bats (but some of them get so wierd I don't count
>all bats into this generalization)
>
>-Betty Cunningham

This is just a guess, but I wonder if it might have something to do with
the development of the ramphotheca, the horny sheath that covers the bills
of modern birds.  Possibly the migration of the nostrils to near the base
of the sheath in some way strengthens the thing structurally, or possibly
makes it less likely that the nostrils will get clogged or injured as the
bird uses its beak for pecking or probing.  

Note, however, that kiwis have their nostrils near the tip of the bill, not
at its base, presumably because smell is important for them in locating
food.  This is, I would expect, a secondarily derived placement.
--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
1825 Shady Creek Court                 
Mississauga, Ontario, Canada L5L 3W2          mailto:ornstn@inforamp.net