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MORRISON TROODONTS



Jon Wagner, our favourite cladist (sorry Jon) writes..

>   d) even then, there are possible troodontid teeth in the 
> Morrison [sic?]

You are probably referring to the tooth-based taxon _Koparion 
douglassi_. Its describer and namer, Dan Chure, no longer thinks that 
_Koparion_ is a troodontid (J. Harris pers.comm. 1997). 

With regard to John's assertion that uncinate processes are 
perhaps phylogenetically informative, Jon also said...

>   Why? Why? Whywhywhy?
>   ON a different suject, is there current aggreement on the 
> presence or absence of uncinate processes on non-avialan dinosaurs?

I am pretty confident that the fighting  _Velociraptor_ specimen has 
uncinate processes preserved _in situ_. Anyone with reference to a 
good photo of the specimen can verify this (I do not have such a 
photo to hand right now). 

John and I discussed uncinates the other day and (perhaps) unlike 
him, I do not regard them as phylogenetically informative, mainly 
because their distribution among taxa is so strange. While 
_Velociraptor_ has them, _Archaeopteryx_ does not (and I do think 
that _Archaeopteryx_ is closer to other birds than are 
dromaeosaurids). Greg Paul thinks that a process figured in Ostrom 
(1979) is an uncinate from _Deinonychus_, but this is difficult to 
prove. At last some enantiornithines have them. They appear primitive 
for ornithurines (they are very evident in _Hesperornis_), but appear 
to have been lost several times among neognathans (emus and screamers 
lack them). And before some of you start to speculate, there is no 
correlation between flightlessness and/or aquatic/amphibious habits 
with loss of uncinates, as numerous groups of flightless and/or 
aquatic/amphibious birds have them.

Before I consult Baumel et al.... time to ask the ornithologists - do 
the rib's uncinate processes have a known function?

"Now nothing can stop us in the raptorisation of Earth!"

DARREN NAISH
darren.naish@port.ac.uk