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

A Brief Look at Wukongopterus

So, with all respect to parties here, I would like to insert a comment on this 
more robustly than I did before. It is true that there may be crushing or 
distortion involved that would discriminate Wukognopterus lii as an abberant 
Darwinopterus modularis, or at least a Wukongopterus lii as a new species of 
Darwinopterus, D. lii. However, some details preclude the argument that 
distortion alone is responsible for their dismimilarity.

1. Maxillary dentition appears to be generally and consistently isoceletic, 
with minimal recurvature; it is only minorly important to note that this 
denition appears labiolingually compressed and, where it is recurved, generally 
ziphodont in form. In *D. modularis*, the dentition is consistently recurved 
and apparently conodont.

2. Dentition almost consistently has an average CBL of 2 or so, less than 3, 
while in *D. modularis* this appears to be more consistently 4 or greater.

3. Clustering of mesial dentition occurs with diminishing size of teeth in *W. 
lii* but not in *D. modularis*.

4. The mandibular postdentary ramus appears to be greater than 4x deeper than 
the corresponding depth of the jugal, while in *D. modularis* this factor is 
less than 3. (The relevant valude of this is discriminant only to these taxa 
for the most part, as the jugal takes on substantial variation in other clades 
so I would not evaluate this feature relative to other pterosaurs; nonetheless, 
it discriminates the provided specimens).

Moving away from the skull, one can postulate postcranial differences, but 
these seem to be very minor and proportional, with one exception:

5. PdV-2, the elongated spur of the fifth toe, is L-shaped in *W. lii*, but 
this element is shallowly curved in *D. modularis* and in virtually every other 
pterosaur that possesses one of these bones.

It should be noted that, without adding details that might discriminate the 
taxa, a given matrix may not yield up distinctions between the two, such that 
when there are distinctions, the taxa would be clustered together, yet still 
distinct (as these are). However, adding in dentition morphology characters 
that can discriminate these taxa (in which *Wukongopterus* teeth resemble those 
of istiodactylids while *Darwinopterus* teeth resemble those of general 
"rhamphorhynchoids") should produce a more complex picture.

The proposition that the mandible has undergone enough distortion to compensate 
for the extreme depth relative to other bones in *Wukongopterus* seems 
untenable, as it would be the only apparent element to have undergone this 
process, being adjacent to other undistorted elements of the skull and 
postcrania, while it at the same time has retained almost all of its apparent 
surface integrity and without distortion relative to other bones (complete 
occlusion with the upper jaw), showing no fractures or breaks aside from that 
which separates the mesial and distal portions of the jaw on the slab; 
*Darwinopterus* specimens are consistent, based only on the type and referred 
material in Lü et al., with respect to their depth, yet show worse preservation 
in some areas (the type) than *Wukongopterus*'s type specimen.

I should note at this point that I consider my cursory examination incomplete, 
and I lack the resources to test the matrices myself through the act of 
encoding the dentition, mandibular proportions, etc. in order to test the 
argument above. I should be able to rectify this at some point, but not now. In 
addition, it is my opinion that these two taxa are distinct, at least at the 
species level. And because I am not a hypocrite and would like to affirm my 
previous stances on nomenclature, if the species as originally named stand, 
then so should their "generic" containers, and as such I would regard *W. lii* 
and *Wukongopterus lii* as being the same essential taxon label; this means I 
would treat *Darwinopterus modularis* and *Wukongopterus lii* as distinct taxa, 
even if they were found as each others' closest sister taxa in every 
forthcoming analysis.


  Jaime A. Headden

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

"Human beings, who are almost unique in having the ability to learn
from the experience of others, are also remarkable for their apparent
disinclination to do so." --- Douglas Adams (Last Chance to See)

"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 

Hotmail: Trusted email with powerful SPAM protection.