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Re: something interesting I didn't know



Farlow,James wrote:
> 
>      I spent most of last week at the Field Museum, looking at study skins
>      and foot skeletons of ratites and other ground birds, and observed
>      something interesting.  I noticed that the big ungual on digit II of a
>      male cassowary, _Casuarius unappendiculatus_, was something like 20%
>      longer than on a similarly sized foot of a female of the same species.
>      The horny claw on digit II on a study skin of a male of _C. bennetti_,
>      and also a male of _C. unappendiculatus_, looked positively enormous.
> 
>      I don't remember seeing anything in the published literature about
>      possible sexual dimorphism in the nasty digit II claw of cassowaries.
>      Does anybody out there know if such sexual dimorphism has in fact been
>      documented in these birds?

Like the emu, it is the male cassowary who incubates the eggs and
raises the young, so a larger "carving knife" claw is no surprise.
Until recently I thought all cassowaries agressive all the time,
but apparently in captivity it is possible to enter their enclosure
at the right times of year (ie. when they are not mating or raising
young). Mind you I said "possible", and not "a good idea". Even when
they are very young they practice their kicking style on unsuspecting
ducks and swans, almost as soon as they are out of the nest.
        Here's another interesting cassowary fact. It was thought
for a long time that the bony crest on their heads acted like a
crash helmet for running through dense vegetation, but apparently
the crest is quite fragile and often breaks (only to regrow).
Therefore display may be its primary function. Could the cassowary
provide a modern analogue for the crested oviraptors? Who knows,
but at least now this posting has some relevance here.

-- 
____________________________________________________
        Dann Pigdon
        Melbourne, Australia

        Dinosaur Reconstructions:
        http://www.geocities.com/capecanaveral/4459/
        Australian Dinosaurs:
        http://www.alphalink.com.au/~dannj
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