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



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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