Re: News story: Did We Get Dinosaurs' Noses Wrong?

["Jordan Mallon" <j_mallon@hotmail.com>]

> From: "Michael Hanson" <mhanson54@home.com>

> What!!!! No lips?!?!?!? Or even a fleshy 
> >covering!?!?!?!?!?!?!?!?!?!?!?!?!?

Nope.

> Just because lizards have lips and crocodiles don't doesn't mean >dinosaurs 
> did not have lips!!!

I would imagine that phylogenetic bracketing would indicate otherwise.  But 
who knows...

> It seems that dinosaurs have small holes in the bottom and outside 
> >surfaces of their maxillary bones and pre-maxillary bones as well as >the 
> tops and outside surfaces of their lower jaw and that these holes >had 
> blood vessels running through them.

Yup.  And Bakker argues that these foramina must have been used to feed 
nutrients to the dinosaurian lips.  This is not true.  Why?
Firstly, the foramina of the dentary would have been completely covered by 
the upper teeth, and according to HP Ford's paper, are too high on the 
dentary to be of any use to the lips.  As Ford points out, these foramina 
are used in lizards to feed the labial glands and the superior alveolar 
nerve and maxillary artery.  What's more, it is believed that Bakker's "lip 
holes" actually served to supply veins and nerve tracks to the teeth, which 
helped with the growth of the teeth and helped the gums while the teeth were 
being replaced.

> If there were blood vessels running through these holes, then there >would 
> be some kind of fleshy covering over the teeth!

I think I should point out here that the maxillary teeth of the _T. rex_ 
known as "Stan" were so large that the so-called lips of the lower jaw would 
have had to have wrapped under and over the upper teeth - something 
fantastical, if you ask me.

> Dinosaurs HAD LIPS!!!!!!!!!!!!!!!

Respectfully: nope! :)

-Jordan Mallon

http://www.geocities.com/paleoportfolio/

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