Re: Making Lip of It

[Jura <pristichampsus@yahoo.com>]

---- Original Message -----

> From: Sim Koning <simkoning@msn.com>

If you look at 
> the open mouth of a lizard such as Komodo dragon, you will notice that their 
> teeth are not even visible despite their large size. If a dinosaur such as 
> Deinonychus had lips of this sort, it would have looked toothless when it 
> opened 
> its mouth. The reality is that the sharp teeth of Varanids actually tend to 
> lacerate the tissue surrounding them. I suspect that this would have been a 
> problem for many theropods, not an advantage. 

++++++++++++++++++++++++++++++++++++++++++++++++

The reason for the apparent toothlessness of many lizards has more to do with 
extensive amounts of gum tissue, not the lips themselves. Exactly why 
lacertilians are so gummy is a mystery I don't think anyone has ever really 
looked at. It might have something to do with the pleurodont/acrodont dentition 
in most groups, and the nutrient requirements for this type of tooth formation. 
If so, then thecodont archosaurs (and, incidentally, mosasaurs) would have 
shallower lips and thus more noticeable teeth regardless of lips. On a related 
note, small lizards also tend to have teeth that are nearly translucent; making 
it even harder to tell where the teeth are (until the little bastards bite you. 
Then it becomes very obvious).

Jason