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RE: Leptorhynchos, new caenagnathid theropod from Late Cretaceous of North America



Indeed, running their base analysis (which took overnight, unlike any analyses 
omitting taxa) causes all of *Caenagnathidae* to collapse into a polytomy with 
*Oviraptoridae*, and thus only the latter is resolved within *Caenagnathoidea*. 
The Adams' consensus is a false assumption of final results, and shows they 
weren't actively testing through a posteriori OTU deletion.

Cheers,

  Jaime A. Headden
  The Bite Stuff (site v2)
  http://qilong.wordpress.com/

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


"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 
Backs)


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> Date: Thu, 25 Apr 2013 17:13:37 -0700
> From: mickey_mortimer111@msn.com
> To: dinosaur@usc.edu
> Subject: RE: Leptorhynchos, new caenagnathid theropod from Late Cretaceous of 
> North America
>
> Actually, that's an illusion caused by them only showing the Adams consensus 
> tree.  In reality, "Leptorhynchus" can be sister to Elmisaurus rarus in the 
> most parsimonious trees, and Longrich et al. included almost none of the 
> proposed Elmisaurus synapomorphies, nor did they even discuss them.  See my 
> blog for more details- 
> http://theropoddatabase.blogspot.com/2013/04/elmisaurus-elegans-no-more-leptorhynchos.html
>
> Mickey Mortimer
>
> ----------------------------------------
> > Date: Wed, 24 Apr 2013 20:46:08 -0400
> > From: archosauromorph2@hotmail.com
> > To: dinosaur@usc.edu
> > Subject: RE: Leptorhynchos, new caenagnathid theropod from Late Cretaceous 
> > of North America
> >
> > They do test this: Leptorhynchos emerges as a caenagnathine, and Elmisaurus 
> > as a non-caenagnathine caenagnathid. (There is an unfortunate error in the 
> > phylogenetic definition of Caenagnathinae sensu Longrich et al. 2013: they 
> > define it as "the clade including all species closer to Caenagnathus coll
ut it is obvious from context that they actually meant E. *rarus* here.)
> >
> > Surprisingly there is no comment on Ojoraptorsaurus, the other recently 
> > named southern caenagnathid.
> >
> >
> >
> >
> > > Date: Tue, 23 Apr 2013 19:41:20 -0700
> > > From: mickey_mortimer111@msn.com
> > > To: dinosaur@usc.edu
> > > Subject: RE: Leptorhynchos, new caenagnathid theropod from Late 
> > > Cretaceous of North America
> > >
> > > I'll be interested to see if Leptorhynchos emerges somewhere besides 
> > > sister to Elmisaurus rarus, so that the new genus for elegans was 
> > > justified. The trend lately has been to ignore E. rarus as somehow not 
> > > oviraptorosaurian. Also note the abstract accidentally lists the 
> > > combination Chirostenotes gaddisi.
> > >
> > > Mickey Mortimer
> > >
> > > ----------------------------------------
> > > > Date: Tue, 23 Apr 2013 19:37:03 -0700
> > > > From: bcreisler@gmail.com
> > > > To: dinosaur@usc.edu
> > > > Subject: Leptorhynchos, new caenagnathid theropod from Late Cretaceous 
> > > > of North America
> > > >
> > > > From: Ben Creisler
> > >
> > > >
> > > >
> > > > A new paper with a new genus of theropod:
> > > >
> > > >
> > > > Nicholas R. Longrich, Ken Barnes , Scott Clark , and Larry Millar (2013)
> > > > Caenagnathidae from the Upper Campanian Aguja Formation of West Texas,
> > > > and a Revision of the Caenagnathinae.
> > > > Bulletin of the Peabody Museum of Natural History 54(1):23-49
> > > > doi: http://dx.doi.org/10.3374/014.054.0102
> > > > http://www.bioone.org/doi/abs/10.3374/014.054.0102
> > > >
> > > > Caenagnathid theropods are a relatively common part of the theropod
> > > > fauna in the Late Cretaceous of Asia and North America, but have not
> > > > previously been described from the southernmost United States. Here,
> > > > we describe caenagnathid fossils from
> > > > Formation of West Texas, and revise the systematics of caenagnathids
> > > > from the Campanian of North America. Caenagnathids from the late
> > > > Campanian of Canada represent three species in three genera:
> > > > Caenagnathus coll
s
> > > > elegans gen. nov. Leptorhynchos is diagnosed by its small size, its
> > > > short, deep mandible, and the upturned tip of the beak. A single
> > > > caenagnathid is known from the late Campanian of Utah, Hagryphus
> > > > giganteus. Two caenagnathid species occur in the Aguja Formation,
> > > > ?Chirostenotes sp. and Leptorhynchos gaddisi sp. nov. L. gaddisi
> > > > differs from L. elegans in that the tip of the beak is narrower and
> > > > less upturned. Phylogenetic analysis recovers Caenagnathidae and
> > > > Oviraptoridae as monophyl
> > >
> > > > North American species seem to form a monophyletic assemblage, the
> > > > Caenagnathinae, within which Chirostenotes and Caenagnathus form a
> > > > clade to the exclusion of Leptorhynchos. The discovery of
> > > > Chirostenotes gaddisi provides more evidence for the existence of a
> > > > distinct dinosaurian fauna in southern North America during the
> > > > Campanian. Furthermore, the Aguja fossils show that caenagnathids were
> > > > widespread and highly diverse in the Late Cretaceous of North Am
> .
> > > > This diversity was maintained in two ways. First, variation in body
> > > > size and beak shape suggests that diversity within formations is
> > > > maintained by niche partitioning, in a way analogous to Darwin's
> > > > finches. Second, diversity is maintained by high degree of endemism,
> > > > with different species of caenagnathids occurring in different
> > > > habitats.