Re: Sclerotics and nose bending

[GJ Dyke <Gareth.Dyke@bristol.ac.uk>]

Most interesting to the study of the evolution of avian skull kinetics
is the case of Confuciosornis sp.. As noticed first by Peters
(1997;Natur und Museum) and Peters and Qiang (1999; Senckenbergiania
lethaea), the skull of these birds, placed most often as the sister-taxa
to Enantiornithes and other birds, has a fused "diapsid configuration",
such that the postorbital and the jugal are fully fused.

So, if the phylogenetic position and interpretation of forms like
Shuuvia are correct, the loss of the fusion of these elements
(characteristic of the prokinetic avian skull) is seen within the
avialae at the level of the alvarezsauridae (and Archaeopteryx ?), but
the fused condition is returned to in the Confuciosornithidae.

Of course, you could use this as evidence for the basal split
(Ornithurae, Sauriurae) in the phylogeny of Mesozoic birds, as Peters
and co have done .... 

This feature of the Confucio. skull is also noted by Hou et al. (1999)
in their description of Confuciosornis dui .... 

Gareth
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Gareth J. Dyke
Dept of Earth Sciences
University of Bristol
Wills Memorial Building 
Queens' Road
Bristol BS8 1RJ UK

http://palaeo.gly.bris.ac.uk/personnel/Dyke/Dyke.html

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