[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: mesosaurus



Tim Williams (twilliams_alpha@hotmail.com) wrote:

<I thought the name "Rhynchocephalia" referenced the rhynchosaurs, which
were once thought to be allied to the tuatara and friends
(sphenodontids).>

  Rhynchocephalia is often used as the of Squamata, in which case if
Rhynchosauria (including *Hyperodapedon*) is an ally of tuataras, then
Rhynchosauria belongs to the Rhynchocephalia. Otherwise, the rest have
been termed Sphenodontia, which to my knowledge it held to be a node based
group including Clevosauridae, Pleurosauridae, Sapheodontidae, and
Sphenodontidae. So there isn't really a 1:1 correllation, but sometimes
there is.

  Darren Naish had this rant (Rhynchocephalia-hatin') way back in 1997:

  "[...]Olivier Rieppel recently re-defined a Rhynchocephalia to include
   Sphenodontida/Sphenodontia and a related genus (dammit I've forgotten
   that name too..). No thanks. I've had it to here with rhychocephalians.
   If people see it used again, they will continue associating
rhynchosaurs
   (which are archosauromorphs) with tuataras (which are lepidosaurs).
   Maybe I should cut down on the coffee."

  (http://dml.cmnh.org/1997May/msg00157.html)

  Hope this helps and clears the confusion. Yes, I see the physical jaw
similarities with basal rhynchosaurs and sphenodonts, too, but they seem
allied to archosaurs....

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


                
__________________________________ 
Do you Yahoo!? 
Read only the mail you want - Yahoo! Mail SpamGuard. 
http://promotions.yahoo.com/new_mail