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RE: Turtle phylogeny (free pdf)

Crawford et al. state "... the crown clade of turtles and archosaurs is an 
unnamed amniote lineage. We fill this important nomenclatural gap, and 
phylogenetically define the name ‘Archelosauria’ to refer to the clade that 
originated from the most recent common ancestor of Crocodylus niloticus 
Laurenti, 1768 and Testudo graeca Linnaeus, 1758."

Is it really an important nomenclatural gap if we have no idea where in 
Archosauromorpha turtles go, assuming they are archosauromorphs?  If you're 
just referring to living taxa, the stem-based Archosauromorpha works fine.  If 
you're referring to fossils, we don't even have a well supported published 
topology for classic groups like trilophosaurs, rhynchosaurs, tanystropheids 
and protorosaurs, let alone the myriad of taxa which may be archosauromorphs 
(simiosaurs, choristoderes, enaliosaurs).  So saying somewhere in that mess is 
a clade called Archelosauria seems pointless.

Mickey Mortimer

> Date: Mon, 17 Nov 2014 08:23:45 -0800
> From: bcreisler@gmail.com
> To: dinosaur@usc.edu
> Subject: Re: Turtle phylogeny (free pdf)
> Errk. Make that Archelosauria...
> On Mon, Nov 17, 2014 at 8:14 AM, Ben Creisler <bcreisler@gmail.com> wrote:
>> Some buzz on Twitter about this paper today, which creates the
>> Achelosauria. The paper is now in open access but is still in
>> manuscript form.
>> On Tue, Nov 4, 2014 at 8:31 AM, Ben Creisler <bcreisler@gmail.com> wrote:
>>> Ben Creisler
>>> bcreisler@gmail.com
>>> A new online paper:
>>> Nicholas G. Crawford, James F. Parham, Anna B. Sellas, Brant C.
>>> Faircloth, Travis C. Glenn, Theodore J. Papenfuss, James B. Henderson,
>>> Madison H. Hansen & W. Brian Simison (2014)
>>> A phylogenomic analysis of turtles.
>>> Molecular Phylogenetics and Evolution (advance online publication)
>>> DOI: 10.1016/j.ympev.2014.10.021
>>> http://www.sciencedirect.com/science/article/pii/S1055790314003819
>>> Highlights
>>> 2,004 Ultraconserved element (UCE) loci resolve relations

>>> living turtles.
>>> The UCE phylogeny is used to test and development a phylogenetic 
>>> nomenclature.
>>> The UCE phylogeny is more consistent with biogeography and
>>> stratigraphy of fossil turtles than morphological hypotheses.
>>> The UCE phylogeny provides a scaffold for paleontological studies.
>>> Abstract
>>> Molecular analyses of turtle relationships have overturned prevailing
>>> morphological hypotheses and prompted the development of a new
>>> taxonomy. Here we provide the first genome-scale analysis of turtle
>>> phylogeny. We sequenced 2,381 ultraconserved element (UCE) loci
>>> representing a total of 1,718,154 bp of aligned sequence. Our sampling
>>> includes 32 turtle taxa representing all 14 recognized turtle families
>>> and an additional six outgroups. Maximum likelihood, Bayesian, and
>>> species tree methods produce a single resolved phylogeny. This robust
>>> phylogeny shows that proposed phylogenetic names correspond to
>>> well-supported clades, and this topology is more consistent with the
>>> temporal appearance of clades and paleobiogeography. Future studies of
>>> turtle phylogeny using fossil turtles should use this topology as a
>>> scaffold for their morphological phylogenetic analyses.