Re: Cassowary Calls Give Insight To Dinosaur Communication

["Muttley" <drinker@alphalink.com.au>]

I'll weigh in here, though I may be out of my depth.

Cassowaries using their crest to make and receive low-frequency sound? I'm
sorry, but I cannot accept that one no matter WHO suggests it - especially
when they liken it to that of Corythosaurus in function. The shape was
similar between the crests of the two (three if you count Lambeosaurus as
well). However, that's where the similarity ends.

As far as I am aware, the crests of both Lambeosaurus and Corythosaurus had
hollows for 'sound production'. This is a workable and eminently acceptable
interpretation of the data available - in fact, I believe Prof.Weishampel
even produced carrying low-grade sound by reproducing the design of the
hollow passages in the crest of Parasaurolophus using PVC piping - si I
can't see why the former two could not have utilised their crests in a
similar manner.

The crest of the Cassowary, however is not made of bone as were the crests
of the hadrosaurs but of dense fibre. It does not contain hollows, but is
solid and dense. The primary use of the Cassowary's crest is for "barging
through scrub and undergrowth" - they live in VERY heavily forested
environments with sometimes almost impenetrable undergrowth. As for the
low-grade sound, Emu's make a very similar call to that of the Cassowary -
it's called 'drumming' and it, too, possesses very low-grade levels
inaudible to humans - and they don't have crests. The live in open
grassland, desert and light forest where a crest would be supefluous.

Frankly, the researchers are going to have to come up with something a lot
better than sound production. I think that it is simply a case of three
different creatures developing a similar apparatus but for different
reasons - two for sound and one for passage creation, 65 million years
apart.

Ask any Australian or New Guinean and they will tell you that the crest is
not a sound-production enhancer or producer. Maybe it picks up sound
vibrations - i'll allow that as a possibility (maybe even a probability),
but never for production. You'd get more sound out of a lump of wood!

Yours

Muttley  (Australia)


----- Original Message -----
From: "Richard W. Travsky" <rtravsky@uwyo.edu>
To: <dinosaur@usc.edu>
Sent: Thursday, October 30, 2003 2:48 AM
Subject: Cassowary Calls Give Insight To Dinosaur Communication


>
> http://wcs.org/7411/?art=110481374
>
> World's Largest Forest Birds May Produce World's Deepest Bird Calls
>
> A family of huge forest birds living in the dense jungles of Papua New
> Guinea emit low-frequency calls deeper than virtually all other bird
> species, possibly to communicate through thick forest foliage, according
> to a study published by the New York-based Wildlife Conservation Society.
>
> Published in the recent issue of the scientific journal The Auk, the study
> says that three species of cassowaries - flightless birds that can weigh
> as much as 125 pounds - produce a booming call so low that humans may not
> be able to detect much of the sound.  The researchers draw similarities
> between the birds calls and the rumbling elephants make to communicate.
>
> When close to the bird, these calls can be heard or felt as an unsettling
> sensation, similar to how observers describe elephant vocalizations, said
> WCS researcher Dr. Andrew Mack, the lead author of the study.
> ...
> The authors and their collaborators are now pursuing studies that examine
> the physics of low frequency sound production and reception. They
> speculate that the cassowaries casque might serve a function in both, most
> likely sound reception.
>
> These investigations are exciting because many dinosaur fossils exhibit
> casques at least superficially similar to those of living cassowaries,
> said Mack.  No one knows for sure what purpose these served in these
> dinosaurs, so further study of living cassowaries might provide clues to
> how dinosaurs communicated."
>
> Coincidentally, the great early 20th Century dinosaur hunter, Barnum
> Brown, described the Corythosaurus, otherwise known as the Corinthian
> Helmet Lizard as cassowary-like.
>
>