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RE: [dinosaur] Apatoraptor, new caenagnathid oviraptorosaur from Late Cretaceous of Alberta, Canada



> -----Original Message-----
> From: dinosaur-l-request@usc.edu [mailto:dinosaur-l-request@usc.edu] On 
> Behalf Of Dawid Mazurek
> Sent: Wednesday, April 13, 2016 6:11 AM
> To: dinosaur-l@usc.edu
> Subject: Odp: [dinosaur] Apatoraptor, new caenagnathid oviraptorosaur from 
> Late Cretaceous of Alberta, Canada
> 
> Dnia Środa, 13 Kwietnia 2016 09:41 Tim Williams <tijawi@gmail.com> napisał(a)
> 
> > One odd feature of the phylogeny is that it recovers
> > _Protarchaeopteryx_ as an archaeopterygid, rather than an
> > oviraptorosaur.  This harks back to the original taxonomic assignment
> > of _Protarchaeropteryx_ by Ji & Ji (1997) as a primitive
> > 'archaeopterygian' (I'm skeptical).  More significant is the recovery
> > of _Luoyanggia_ and _Ningyuansaurus_ as basal oviraptorosaurs, of the
> > same evolutionary grade as caudipterygids.
> >
> 
> Also, _Archaeopteryx_ is here closer to oviraptorosaurs than to 
> _Velociraptor_. I really enjoy the idea that a Middle-Upper
Jurassic
> grade of archaeopterygid 'birds' actually gave rise to all other groups of 
> Pennaraptora, most of them becoming 2F. The majority of
> phylogenetic analyses do not follow this scenario, but I quess this might be 
> because of secondary, reversal 'terrestrialization'
of
> morphology. This would be more in line with the stratigraphic occurence of 
> main radiations of pennaraptoran ingroups.

I would respectfully urge folks to calm their jets with regards to these 
positions. Look at the analysis; look at the characters and
states involved; look at the taxon choice. This matrix is utterly incapable of 
sorting out any reasonable relationships among
anything but Oviraptorosauria: there are only four non-oviraptorosaur taxa in 
the matrix, one of which is fixed in position as the
outgroup. Using this matrix to assert evidence for a new position for 
Archaeopteryx is ridiculous, and is NOT what this analysis is
testing at all.

NO analysis can ever simultaneous test all parts of the tree equally well. 
Taxon and character sampling are chosen to be relevant to
the hypotheses under examination.

Please don't take the basal nodes of this--or any--phylogeny as representative 
of the results of the analysis. Those taxa at the
base are included in the matrix to help establish the character polarity at the 
basal node for the group under study.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu         Phone: 301-405-4084
Senior Lecturer, Vertebrate Paleontology
Office: Geology 4106, 8000 Regents Dr., College Park MD 20742
Dept. of Geology, University of Maryland
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Mailing Address:        Thomas R. Holtz, Jr.
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