[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: Phylogenetic taxonomic definitions in Xiaotingia paper



I'm reading today's posts from the earliest to the latest, so if this has been 
said, I will hope I am not retreading old ground:

  I'd rather see re-invented definitions of old clade names than people coining 
new names for new definitions. This may be a false dichotomy, as there is a 
middle ground (shifting taxa not requiring new definitions) but Xu et al. seem 
to prefer the robustness of their clades and the familiarity of their taxa (and 
their utility) more stable with their chosen specifiers, or with exclusive 
specifiers of their newer choice.

  Stability of the definitions of clades will not come until PhyloCode is 
enacted and those who choose to follow it (I am not sure if this includes Xu 
Xing, but know it does not include Paul Sereno), and then those who choose to 
define clades settle on a basis. Nothing tells us that the most recent or 
earliest clade definition should stand, otherwise we should never accept any 
redefinition from _anyone_, just the first (prime) definition ever published. 
This is what stops multiple people from nomenclating the same specimen at will, 
a point of no return for definitions. Complaining about it (Mickey, I'm a 
world-class complainer, and _I'm_ glaring at _you_...) does us no good.

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)


----------------------------------------
> Date: Wed, 27 Jul 2011 14:48:18 -0700
> From: mickey_mortimer111@msn.com
> To: dinosaur@usc.edu
> Subject: RE: Phylogenetic taxonomic definitions in Xiaotingia paper
>
>
> Ack.  I wish people would stop redefining clades left and right.
>
> Coelurosauria is part of a simple node-stem triplet.  We don't need to define 
> Sinraptor and Carcharodontosaurus out of it.
> Avialae is ALSO part of a simple triplet, and Troodon does not need to be 
> defined out of it.
>
> The whole point of phylogenetic definitions is to be stable so that we know 
> what clade we're discussing at any time.  If we keep on adjusting them, that 
> defeats the purpose.
>
> Mickey Mortimer
>
>
> ----------------------------------------
> > Date: Wed, 27 Jul 2011 13:44:06 -0400
> > From: tholtz@umd.edu
> > To: dinosaur@usc.edu
> > Subject: Phylogenetic taxonomic definitions in Xiaotingia paper
> >
> > >From the supplemental material:
> >
> > "We used the following definitions of several higher-level theropod taxa
> > in this paper: Coelurosauria, the most inclusive clade containing Passer
> > domesticus Linnaeus 1758 but not Allosaurus fragilis Marsh 1877, Sinraptor
> > dongi Currie and Zhao 1993, and Carcharodontosaurus saharicus Depéret and
> > Savornin 1927; Paraves, the most inclusive clade containing Passer
> > domesticus Linnaeus 1758 but not Oviraptor philoceratops Osborn 1924;
> > Avialae, the most-inclusive clade containing Passer domesticus Linnaeus
> > 1758 but not Dromaeosaurus albertensis Matthew and Brown 1922 or Troodon
> > formosus Leidy 1956; Deinonychosauria, the most-inclusive clade containing
> > Dromaeosaurus albertensis Matthew and Brown 1922 but not Passer domesticus
> > Linnaeus 1758; Archaeopterygidae, the most inclusive clade including
> > Archaeopteryx lithographica Meyer 1861 but not Dromaeosaurus albertensis
> > Matthew and Brown 1922 or Passer domesticus Linnaeus 1758."
> >
> >
> > Thomas R. Holtz, Jr.
> > Email: tholtz@umd.edu Phone: 301-405-4084
> > Office: Centreville 1216
> > Senior Lecturer, Vertebrate Paleontology
> > Dept. of Geology, University of Maryland
> > http://www.geol.umd.edu/~tholtz/
> > Fax: 301-314-9661
> >
> > Faculty Director, Science & Global Change Program, College Park Scholars
> > http://www.geol.umd.edu/sgc
> > Fax: 301-314-9843
> >
> > Mailing Address: Thomas R. Holtz, Jr.
> > Department of Geology
> > Building 237, Room 1117
> > University of Maryland
> > College Park, MD 20742 USA
> >
>