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FW: My Gr. 9 Sc. Fair Project Summary



(oops, heh-sorry chris-mickey)

impressive body of work.  Good going, Della!
I have a question ('cause it never occured to me before, until I read   
this.)
you said:
(snip)

> The hairs inside the cochlear duct send messages to the auditory
> nerve.  The stiffest hairs are located near the beginning of the
> duct and are used to detect high frequencies.  The soft hairs
> located deeper within the duct are used to detect low
> frequencies. (Ritter et al.)  Of course, no one has ever seen these
> structures in a dinosaur because they have not been fossilized.  I
> assume that the soft tissues of dinosaur ears were much like those
> of living birds and reptiles.

What do modern birds and reptiles use instead of hair? Modified scales?   
 Feathers? Some other system entirely?

[ The word "hair" in "hair cell" has absolutely nothing to do with the
  "hair" that covers the bodies of mammals.  Hair cells are
  phylogenetically ancient -- much more ancient than the hairs of
  mammals.  The "hairs" of hair cells are cilia. -- MR ]

I don't see a reference in your Bibliography to a study or book on modern   
reptile and bird hearing so as to properly define what a dinosaur would   
be likeley to have, since fossil evidence is missing.

> "On the whole reptiles (and even birds) have much poorer hearing
> than most people realize.  The best guess is that they can use
> auditory information in a narrow sense, as if they have a tuned
> receiver that responds appropriately for signals within a narrow
> range of profiles.

You will need to prove the importance of the cochlear duct in modern   
reptiles and birds and you will need to show a print reference so as to   
demonstrate your understanding of the process (which is better than mine,   
currently).

 -Betty Cunningham