Dino Vocalizations: My Previous Attachment

[drury@agt.net]

I've been advised that some of you are having trouble retrieving the
attachment in my most recent message.  I'm going to try pasting it directly
into this message.  Here's hoping!


Title:   Blasts From the Past:  Ancient Melodies
        by Della Drury

Questions:      1.  What vocalizations may have been produced by hadrosaurian
                    dinosaurs using the resonating chambers in their crests?

                2.   Is there any evidence that hadrosaurian dinosaurs had
                     soft tissue structures that would have let them
                     change the size of the resonating chamber in
                     their crests?

                3.  Could the lateral diverticula in the crests have been
                    used to modify the vocalizations?

                4.  Is there any evidence of vocal cords or their supporting
                    boney structures in the throats of hadrosaurian
                    dinosaurs? (If these structures existed, they may
                    have changed the pitches or complexity of the
                    sounds produced.)

                5.  Could some adult hadrosaurian dinosaurs have produced
                    frequencies that their predators could not hear?

Hypothesis:  Hadrosaurs used their crests as resonance chambers to produce
low frequency vocalizations which their predators could not hear.

Procedure:      1.  Collect data from each of the following sources:
                                a)  books
                                b)  periodicals
                                c)  internet articles
                                d)  paleontology bulletin boards
                                e)  postal letters from museums
                                f)  e-mail from paleontologists

               2.  Based on the best data from the above sources, build a
                   plastic pipe model of a Parasaurolophus nasal cavity.

               3.  Calculate resonant frequencies based on measurements
                   from the literature and, more specifically, of the
                   plastic model.

               4.  Generate various frequencies using the model and measure
                   the frequencies using either an oscilloscope or a
                   frequency counter.  Compare the measured and
                   calculated frequencies.

               5.  Find data on the length of the cochlear ducts in the ears of
                   predators which may have eaten hadrosaurs.  Use
                   these lengths to calculate the lowest frequencies
                   these animals would have been able to hear.
                   Compare these frequencies to those which hadrosaurs
                   would have been able to produce.