Talk:Rauisuchia

From Wikipedia, the free encyclopedia

[edit] Teratosauridae

The problem with the uncertain placement of Teratosaurus is that whichever family it belongs to would be named Teratosauridae (von Meyer, 1861) under ICZN priority rules. I think we should follow the two most recent analyses and place T. and Postosuchus in "Rauisuchidae", and move that article to Teratosauridae.Dinoguy2 12:20, 11 May 2006 (UTC)

Okay first I got the references re Teratosaurus as Rauisuchidae from the Dinosaur Mailing List Archives; i havent read those two papers myself. Also I don't know what the layest consensus on this is, as those posts are quite old by now.

re Postosuchus - I have also seen a few statements on the web (including one on the DML) that "Postosuchus may be/is a Rauisuchid", but i have not seen any citation supporting this, so it is just heresay.

Re ICZN priority and Teratosauridae, sometimes these rules have been overruled - e.g. it was decided not to rename T. rex by some other name (i forget which) that was earlier. Priority is not always adhered to, e.g. Podokesauridae is older than Coelophysidae; that being the case why is the entry on Wikipedia called "Coelophysidae" ;-) Rauisuchidae, not Teratosauridae, is the name that appears in the scientific journals in this context (check Google Scholar - wonderful resource! - if you don't beleive me); it is not our role to undertake "original research" here. So I am strongly against renaming "Rauisuchidae" as "Teratosauridae" UNLESS that is first done (and the case argued for it) in a published, peer-reviewed, scientific journal, which can then be cited in the references.

So I would leave Postosuchus as a Poposaur UNLESS peer-reviewed references turn up indicating the contrary. Re Teratosaurus, the taxobox should have a dual family link reflecting the classification controversy, and the controversy mentioned in the Teratosaurus page, including the refrences by Parrish, Galton & Walker & Long & Murray added to the references section (neither of these articles i've read so i am just going by DML hearsay here in including them, but that's Wikipedia, always a work in progress!)

M Alan Kazlev 00:22, 12 May 2006 (UTC)

ICZN rules are ICZN rules. "Coelophysidae" should indeed be Podokesauridae, I'll see about changing this when I have a chance. T. rex is preserved over Manospondylus gigas via special (and citable clause) declaration of the ICZN, which does not exist for Coelophysidae or Rauisuchidae. As far as I know, the only reason Teratosauridae is not used universally in the literature is because the position of Teratosaurus is uncertain. Once it becomes certain, barring special intervention by the ICZN, it *must* be contained in a family named Teratosauridae, if it's not a plesion.Dinoguy2 07:24, 12 May 2006 (UTC)

Fair enough! I think it will be pretty difficult to reach consensus if all one has to go by is a single fragment of maxilla. Anyway we'll see what the paleontological community decides re this genus.

btw Dinoguy, do you know what the situation is re Titanosauridae vs Saltasauridae? It has been shown that the former is based on a nomen dubium. To quote from my Jeffrey A. Wilson write-up:

Wilson, J.A. and Upchurch, P (2003) A revision of Titanosaurus Lydekker (Dinosauria-Sauropoda), the first dinosaur genus with a "Gondwanan" distribution, Journal of Systematic Palaeontology Volume 1 Issue 3 - September 2003 (a revision of 14 species of the genus Titanosaurus shows that only five of these are valid. The type species T. indicus is considered a nomen dubium, and therefore the abandonment of suprageneric taxa based on it - e.g. Titanosaurinae, Titanosauridae, and Titanosauroidea - is suggested. The species T. colberti is renamed Isisaurus colberti)

Wilson for this reason suggests using Saltasauridae. In Curry Rogers & Wilson eds. 2005, The Sauropods: Evolution and Paleobiology, some writers use Saltasauridae, and some still use Titanosauridae etc. I am not an expert in this field, but it seems like this is a clash between the new, cladistic-based phylocode and the old Linnaean-based approach. Do you know where the ICZN stands on this? M Alan Kazlev 21:37, 12 May 2006 (UTC)

I can't find a statute on the ICZN site which says supragenric taxa based on nomen dubia must be abandoned (except if the type genus has been suppressed or the family name would be a homonym of another family name), but I may have overlooked it. As I mentioned on (I think) the Titanosaur talk page, this abandonment is not consistant with other families still in use and based on nomen dubia, like Hadrosauridae, Ceratopsidae, and Megalosauridae. The idea of abandoning Titanosauridae and not those taxa seems arbitrary to me. If PhyloCode does go into effect, and Saltasauridae is defined instead, this would be a direct conflict between PhyloCode and the ICZN (though I guess that could happen with any family name).Dinoguy2 23:22, 12 May 2006 (UTC)

[edit] Paraphyly of Rauisuchia

The page http://www.fmnh.helsinki.fi/users/haaramo/Metazoa/Deuterostoma/Chordata/Archosauria/Pseudosuchia/Suchia has the clade Paracrocodylomorpha nested within Rauisuchia, with crocodylomorphs, poposaurids, ctenosauriscids, and their ancestors having descended from the Rauisuchidae. Further, the family Prestosuchidae is the sister clade to the clade Rauisuchiformes (=Pseudosuchia), and the family Poposauridae is more related to the family Ctenosauriscidae than to Rauisuchidae, thereby forming the clade Poposauria. Therefore, update the Rauisuchia.

The debate over whether or not Rauisuchia is paraphyletic or monophyletic is already discussed in the article. Did you read it?Dinoguy2 13:37, 26 November 2006 (UTC)