Re: Making Lip of It

[Jura <pristichampsus@yahoo.com>]

Lion image sent one more time due to the Yahoo snippy demon.

http://4.bp.blogspot.com/-Tdxwg9Tz26c/TazEaWSW8nI/AAAAAAAAA0k/p3hQ-WDztcQ/s1600/lion-the_chase.jpg


----- Original Message -----
> From: Jura <pristichampsus@yahoo.com>
> To: "dinosaur@usc.edu" <dinosaur@usc.edu>
> Cc: 
> Sent: Thursday, 22 September 2011 10:35 PM
> Subject: Re: Making Lip of It
> 
> ----- Original Message -----
> 
>>  From: Augusto Haro <augustoharo@gmail.com>
>> 
>>  Besides, I think that another (rather weak, I admit) argument to say
>>  lizard-like lips were not present in non-avian dinosaurs (accepting
>>  their function is to keep teeth wet) may be that carnivorous dinosaurs
>>  and some archosauriforms have teeth generally longer than most
>>  carnivorous squamates. Thus, the lip should be generaly longer than in
>>  a lizard. For the dinosaur to bite something, and the long teeth to
>>  enter deeply into the flesh, the lip should be raised. This required
>>  to raise a bigger lip, which would require more lip musculature.
>>  Perhaps mammals can accomplish raising bigger lips which commonly
>>  protect longer canines because the larger amount of voluntary muscle
>>  present. Lizard teeth are commonly so short (or, when long as in
>>  snakes and monitors, so caudally pointing) that perhaps the lip has
>>  not to be raised too much more than passively for the teeth to mostly
>>  penetrate prey.
>> 
> 
> +++++++++++++++++++++++++++++++++++++++++++
> 
> I'm not sure how necessary lip musculature would be for this. Unless the 
> lips were overhanging to such a degree that they could fold inward on the 
> teeth, 
> I'd suspect that passive suspension on the jaw would be all that's 
> needed to allow the teeth to pierce through prey (whose own bodies should 
> provide enough resistance to allow the teeth to move beyond the lips. A 
> similar 
> situation like this is believed to exist in Komodo dragons, except that it 
> involves the gums instead of the lips. Mammal lip musculature is certainly 
> impressive, but all the cases of lip raisi
olves) are always done as a signal to congeners (typically telling them to back 
> off). The infamous Indian tiger attack on a man riding an elephant seems to 
> show 
> that regular attacks don't really require pulling the lips out of the way. 
> 
> http://www.crazy-videoz.com/wp-content/uploads/2011/01/tiger-attack-man-on-elephant.jpg
>  
> (blurry, but effective).
> 
> http://4.bp.blogspot.com/-Tdxwg9Tz26c/T
> with a lion).
> 
> Jason
>