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RE: Mr. Fantastic New Papers, Wukongopterus



Dave,

  There do seem differences between these three taxa (*Pterorhynchus,* 
*Darwinopterus* and *Wukongopterus*), although I would be presumptive in my 
scanning of the last description to assume I can quantify them all to a 
substantive degree. Between the first two, there are at least 18 differences 
(based on the analysis in which both were included -- neither were included in 
the last analysis):

  Rostral index and preorbital cranial length are both greater in *D* than in 
*P;* and in *P* (as assumed from Czerckas and Ji, 2002) that there is a thin, 
slit-like bony external naris as in, but smaller, than *Angustinaripterus*, 
which invovles several dependant features in the analysis (13-14, 17, 19-21); 
shape of the lachrymal and shape/size of the orbit, position of the mandibular 
joint relative to rostrocaudal length of the orbit; greater numbers of 
dentition in *D* than in *P;* longer cervical vertebrae and differing features 
of the cervical neural spines; and finally, a longer md4 relative to 
tibiotarsus in *D* than in *P.*

  *Wugongopterus* shares many aspects with *Darwinopterus,* but for these 
features one could presume the same of *Pterorhynchus,* and the taxa also 
differ in the shape of the mandible and its robusticity, as well as the shape 
of the teeth. In *W,* the teeth are all shorter, slightly recurved, and cluster 
tightly in the rostral tip, and the mandible is deep relative to its length 
despite being similar in size to that of a specimen of *D* with which it can be 
compared bone for bone. *Darwinopterus*' teeth are elongate, conodont in aspect 
and bear slightly fluting, and more widely spaced at the rostral tip.

  Similarities between the specimens may be presumed to concern common descent 
rather than direct application to the same taxon, given the distinctions 
between the specimens (mainly cranial) which do not involve the key aspects of 
cervical elongation, pteroid elongation, or retention of a long fifth toe while 
also involving apparent opening of the nasoantorbital fenestra in one (and 
potentially all of them, if Czerkas and I were mistaken and there is a 
split-like nasal in the skull rather than a tiny, slit-like naris in the 
rostral cranium) that are involved in the argument that these taxa are 
intermediate between the "rhamphorhynchoid" and "pterodactyloid" morphologies.

  I detail several of my arguments on *Pterorhynchus* and *Darwinopterus* at my 
blog, here: 
http://qilong.wordpress.com/2009/10/22/some-thoughts-on-darwinopterus/

Cheers,

Jaime A. Headden

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


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"Ever since man first left his cave and met a stranger with a
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Backs)





----------------------------------------
> Date: Sat, 14 Nov 2009 10:47:38 -0600
> From: davidpeters@att.net
> To: dinosaur@usc.edu
> Subject: re: Mr. Fantastic New Papers, Wukongopterus
>
> Wukongopterus
>
> Dang, same things as Darwinopterus (Lü et al. 2009, Oct. 14) , but with a 
> different spin. Wonder if they knew about each other's work?
>
> David Peters
>
>
                                          
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