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Re: Gnathosaurus question

Dave Peters (davidrpeters@earthlink.net) wrote:

<Gnathosaurus is well known for having a spoon-shaped rostrum. But the
dentary assigned to this genus does not appear to be spoon-shaped (see
Wellnhofer 1991). Am I missing something here?
This becomes important to Dr. Unwin's hypothesis linking Cearadactylus
atrox to Gnathosaurus cladistically, because he notes that Cearadactylus
has a spoon-shaped dentary, much wider than its not-so-spoon-shaped

  Well, the argument is flawed, in my opinion. 1) The dentary may be
falsely assigned to *Gnathosaurus.* 2) The dentary, contra the upper
rostrum, may lack the mediolateral expansion, something seen in the
"spatula-"snouted croc *Terminonaris,* and to a limited degree in its
relative *Sarcosuchus,* so it is possible. To my knowledge, while
*Huanhepterus* has the downturned, expanded upper rostrum, the lower is
not expanded, as well. The modern spoonbill, *Platalea,* also lacks a more
distinct lower expansion than the upper jaw does.

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)

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