Re: New alvarezsaurid

["Matthew Troutman" <m_troutman@hotmail.com>]

>How many is many, many, many, many, many, many? Most modern birds have 
lost
>(or secondarily changed) enough derived characters that it has become
>extremely difficult to determine their suprafamilial relationships from
>morphology. The avian DNA cladogram is quite a bit different from the
>morphological avian cladogram.
>

    Say, loss of :

The three tymapanic recesses. 
Lack of contact between postorbital and jugal and squamosal.
Carina. 
Peg-like coracoid. 
Shortened caudal series.


    The problem in the avian cladograms is trying to tell what is 
primitive and what has evolved because of behavior. The avian DNA 
cladogram has been often maligned because of misinterpretations of 
measurements, lack of appropriate outgroups, etc. There are cases when 
thorough study is done and the true picture emerges. In trying to 
determine barbet and toucan phylogeny in the Piciformes (woodpeckers, 
toucans, barbets) a University of Kansas ornithologist concluded that 
the barbet family ( Capitonidae ) was not monophyletic, which was a 
controversial conclusions. This has been concurred by many workers later 
on. Interestingly, now, we think that there are no New World barbets, 
all the New World barbets are toucans. This conclusion is now accepted 
by DNA and morphological evidence. When evidence is weighed correctly, 
cladograms can be considered correct.

MattTroutman

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