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Re: Making Lip of It



On Thu, Sep 22nd, 2011 at 6:03 PM, David Marjanovic <david.marjanovic@gmx.at> 
wrote:

> >  I think they were referring to a greater degree of overbiting, where
> >  the upper tooth spans most of the height of the lower jaw (as in the
> >  canines of cats or the teeth of Dilophosaurus).
> 
> Even so, the canines of cats are fully covered by lips.

Some siamese cats develop super-occluded upper canines that permanently 
protrude below the 
lips. I don't know whether it causes them any problems. It certainly makes them 
look creepy.

Sabretoothed cats certainly seem to have coped with permanently exposed 
canines. As do extant 
male musk deer. Naked mole rats have forgone lips altogether - although their 
burrows probably 
maintain a constant level of humidity, and their teeth grow and are worn down 
at a much greater 
rate than for most mammals.

-- 
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Dann Pigdon
Spatial Data Analyst               Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj
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