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My Gr. 9 Science Fair Project



I have received a message from Dr. Darren Tanke of the Tyrrell which says in
part: "You might also contact Dr. Larry Witmer. Not sure where he is now. I
have a one paragraph article by him called Mechanisms of Sound Localization
in some Fossil Archosaurs. He might be able to provide some information for
you."

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*Does anyone know where I can contact Dr. Larry Witmer?*
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Since so many of you seem to be interested in my project, here is a brief
update.

1)      I've been advised by several of you that, although the cochlea is a
bony structure, it is delicate an is usually crushed and distorted during
fossilization.  Although it is possible in some cases to approximate the
dimensions of the cochlea from the void in the larger bones which encased
it, these measurements are not routinely made.  Therefore, it seems unlikely
that I am going to be able to find the data I need on theropod ears.

I'm currently trying to find data on the ears of reptiles and birds as a
second choice.

2)      Dr. Phillip Currie of the Tyrrell and Dr. Harry J. Jerison of
U.C.L.A. have both advised me that hearing is more complex than I had
originally imagined.  Dr. Currie has reccommended a reference, *WEVER, E. G.
1978. The reptile ear, its structure and function. Princeton University
Press, Princeton, New Jersey. 1024 pp.*  My local librarian is trying to
find it for me on inter-library loan.

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*I'm still looking for good references on bird ears.*
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Dr. Currie has told me that some theropods had diverticula in the middle ear
to amplify specific frequencies.  I'm tempted to say that these diverticula
acted as closed air columns and that I can calculate the frequencies that
were important to theropods by getting data on the lengths.  Besides the
difficulty of getting the measurements, I am remembering the warnings about
how complex hearing is.  If I can find enough in the references to explain
hearing, perhaps I can still find a way to do something with this idea.

Both Dr. Currie and Dr. Jerison have suggested that theropods probably
evolved their ability to hear low frequencies as quickly as hadrosaurs
evolved the ability to produce them.  This is the closest I've come to a
'test' of my hypothesis.

3)      Dr. Cathy Forster of the State University of New York has sent me
fifteen scale diagrams of hadrosaur skulls.  I am currently making
measurements in preparation for calculating the resonant frequencies.  I am
especially grateful for her contribution.

4)      Several of you have gone to great lenghths to point out that my
hypothesis is *hypothetical*.  At first, I didn't know what to make of all
this but I got some timely encouragement from my father who pointed out,
"You can tell you're getting close to the frontier of knowledge when the
experts start to disagree with each other."

5)      The Science Fair at my school takes place on Feb. 13.  You'll
probably be seeing more messages before then!  At the very least, I will
post a copy of my final project summary sometime soon.

Thanks again to all of you who have been so helpful!  Paleontologists seem
to be a wonderful group of people!

Della Drury