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Fwd: Re: The Eternal Question: Lips or Skin?



Jon Wagner asks me to forward this to the list:

-=------------------------------------------------=-

--- kritosaurus <kritosaurus@netzero.net> wrote:
> Reply-to: "kritosaurus" <kritosaurus@netzero.net>
> From: "kritosaurus" <kritosaurus@netzero.net>
> To: <qilongia@yahoo.com>
> Subject: Re: The Eternal Question: Lips or Skin? 
> Date: Wed, 8 Aug 2001 10:56:34 -0500
> 
> Jaime, please forward this reply to the list.
> 
> Jaime wrote:
> >Mike Hanson seems to adamantly state that they do, for one reason,
> >apparently: maxillary and dentary mental foramina. These are
> >extensive in other reptiles (those that hd legs, anyway), but this
> >issue of lips in lizards is not the same as for mammals.
> >[...] Reptiles have extensive gums, mind, and lizards lack lips in
> >the mammalian sense. In this way, they resemble other reptiles in
> >having a tendonous band of tissue that wraps around the oral
> margin,
> >with some very few muscles attaching to the margins ... the they
> are
> >there to hide the teeth only. They are not conventional "lips"
> sensu
> >Mammalia.
> 
>     a) As Mark Hallett points out, I doubt very much that lizard
> lips ONLY
> "hide the teeth." My little Pogona vitticeps seals his mouth up
> rather
> nicely with his lips... his teeth are so small they don't need to
> be hidden
> anyway.
> 
>     b) One thing often forgotten: EVOLUTION HAPPENS. It is entirely
> conceivable that the lips of lizards and mammals may be homologs,
> with the
> lips of mammals being substantially derived from the common
> ancestral form.
> 
>     c) With all respect to Dr. Holtz's turf: WAIT FOR THE PAPER!
> Without
> seeing Dr. Witmer et al.'s full battery of evidence, all of this is
> speculative, and somewhat inappropriate (in my opinion). No more
> inappropriate than the wholesale adoption of the "Witmer Group
> reconstruction" by some paleo-artists, mind you...
> 
> >The nerves that exit the foramina (the maxillary
> >branch of the maxillopharyngeal nerve) are strictly involved with
> the
> >gums.
>     So that we are clear, the best interpretation I have seen is
> that the
> neurovasculature package which exits via the foramena on the
> "labial" margin
> of the dinosaurian maxilla appears to be associated with the
> maxillary
> branch of the trigiminal nerve.
> 
>     Wagner
> 
> Jonathan R. Wagner
> 9617 Great Hills Trail #1414
> Austin, TX 78759

  I stand chastized about which nerve ennervates the maxilla (also
noting that Waylon Rowley used the same nerver, trigeminal)...


=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

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