Re: Prolacertiformes and Protorosauria

[Jocelyn Falconnet <j.falconnet@gmail.com>]

David Marjanovic a écrit :
> > > That's not how it works. In the ICZN, precedence does not apply
> > > above the family group of ranks; the PhyloCode still isn't
> > > implemented and won't be retroactive. So, do what you want.
> >
> > True.  But it's still at least _polite_ to follow priority of clade
> > definitions in the absence of a compelling reason not to.
>
> Yes. I should have added "but think long and hard about what you 
> really want".
>
> For example, it's not even clear whether *Prolacerta* and 
> *Protorosaurus* form a clade that excludes the archosaurs...
You're right David. A redescription of Protorosaurus by Annalisa 
Gottman-Quesada and Martin Sander was published a few months ago in 
Palaeontolographica A. In their phylogenetic analysis:
- The so-called 'Protorosauria' or 'Prolacertiformes' in the classical 
sense are polyphyletic
- All 'protorosaurs'/'prolacertiforms' are archosauromorphs
- Protorosaurus and Megalancosaurus form a clade (Protorosauria)
- Tanystropheus and Macrocnemus form a clade (Tanystropheidae)
- Pamelaria is the sister-group of (Prolacerta + Archosauriformes)
- Prolacerta is the sister-group of Archosauriformes

____Youngina
|____Gephyrosaurus
 |  |__Squamata
 |_____Champsosaurus
  |______Megalancosaurus
   |   |____Protorosaurus
   |_______Tanystropheus
    |   |_____Macrocnemus
    |________Trilophosaurus
     |   |_______Mesosuchus
     |     |______Rhynchosaurus
     |________Pamelaria
         |_______Prolacerta
           |_______Euparkeria
             |______Proterosuchus

If Megalancosaurus is deleted from the analysis, Protorosaurus and 
Tanystropheidae form a trichotomy with (Pamelaria (Prolacerta + 
Archosauriformes)). Now it would be interesting to include other 
avicephalans (Coelurosauravus, Longisquama, Drepanosaurus, Hypuronector, 
Dolabrosaurus, ...) and also pterosaurs (but in this case, other 
archosaurs would be necessary).

Reference:
Gottman-Quesada A. & P. M. Sander. 2009. A redescription of the early 
archosauromorph Protorosaurus speneri Meyer, 1832, and its phylogenetic 
relationships. Palaeontolographica Abteilung A: Paläozoologie - 
Stratigraphie 287 (4-6): 123-221, 30 figures, 4 tables.

--
Jocelyn FALCONNET
PhD student -> The early radiation of amniotes
Supervisors -> J-C Rage and J-S Steyer (MNHN)

CR2P, UMR 7207, CNRS
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