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RE: The Croc That Wanted to Be a Dinosaur
_Poposaurus gracilis_ is not a poposaurid?
What species does belong to _Poposaurus_?
Mikko K. Haaramo, M.Sc.
Paleontologist IT Manager
Department of Geology
P.O.Box 64 (Gustaf Hällströminkatu 2)
FIN-00014 University of Helsinki
www: Mikko's Phylogeny Archive [http://www.fmnh.helsinki.fi/users/haaramo/]
> -----Original Message-----
> From: firstname.lastname@example.org [mailto:email@example.com]
> On Behalf Of Jaime A. Headden
> Sent: 29. tammikuuta 2006 6:27
> To: firstname.lastname@example.org
> Subject: RE: The Croc That Wanted to Be a Dinosaur
> There are several "family-level" names available for this group of
> Poposauridae Nopcsa, 1928
> Ctenosauridae Kühn, 1961
> Ctenosauriscidae Kühn, 1964 (revised)
> Lotosauridae Zhang, 1975
> Shuvosauridae Chatterjee, 1993
> Chatterjeeidae Long and Murray, 1995
> Taxa included (potentially, following Nesbitt, 2003, 2005
> and Nesbitt and Norell, 2006):
> *Hypselorhachis mirabilis*, *Lotosaurus adentus*,
> *Cteosauriscus koeningi*, *Chatterjeea elegans*, *Shuvosaurus
> inexpectatus*, [new taxon, Nesbitt and Norell, 2006],
> *Sillosuchus longicervix*, *Poposaurus gracilis* (incl.
> *Lythrosuchus langstoni*?), *Bromsgroveia walkeri*,
> *Arizonasaurus babbitti*
> These animals appear to form a clade apart from rauisuchids
> or poposaurids proper (*Rauisuchus*, *Teratosaurus* sensu
> Dzik, *Poposaurus*, *Postosuchus*, *Saurosuchus*,
> *Tikisuchus*, etc.), and in which perhaps the tall dorsal
> spines are prevalent before the presence of beaks becomes
> more extensive in the only [three] taxa to bear them, one
> which has a sail and one which does not, the other being
> unknown in this condition and perhaps synonymous with the latter.
> *Lotosaurus* also has the shortest sail of the
> "ctenosauriscids" and so it might be worth considering that
> the sail was being minimized, perhaps moving the animal into
> an environment or population structure that did not require it.
> If we choose to use a single name for these animals,
> Poposauridae Nopcsa has priority. If we choose to name each
> small grouping of taxa with an -idae clade, we might still
> require a more inclusive name to set these apart from the
> "rauisuchids" or "teratosaurids" or "prestosuchids" that form
> this complex or grade of basal suchians. It might be easiest
> to use the given nomenclature and modify from it, reducing
> the need for excessive -idae clades. One could use
> "Paniphora" for the clade including the first fin-back, and
> for those toothless clades, included by "Paniphora", and
> avoid the whole Linnaean quagmire of -idaes and -inaes and
> names "changing ranks".
> There is an odd biogeographical conundrum to draw from this
> *Hypselorhachis* and *Ctenosauriscus* are both from
> southern Africa, and their jaw anatomy is unknown, though
> perhaps some of those southern African crania may belong to
> something like them rather than classically rauisuchid like
> *Postosuchus* (that means you, *Alwalkeria*). *Lotosaurus* is
> from China.
> *Sillosuchus* is from South America. *Bromsgroveia* is from
> England. And all the rest are from North America (actually,
> to be precise, to the American Southest). While the Late
> Triassic continents were largely in connection to one
> another, many of these taxa appear to form a general gradient
> with regarded to cranial, and sail, anatomy, with Nesbitt and
> Norell finding a grouping of tall-spined taxa, and within
> that a grouping of *Arizonasaurus* and *Ctenosauriscus*;
> *Bromsgroveia* may also belong to this group. *Lotosaurus* is
> allied, but as shown with the crania, clearly represents an
> edentulous lineage with *Shuvosaurus* and the new taxon. If
> we assume such consistency, these taxa have essentially been
> "bouncing" around the globe, and the North American taxa may
> not form a single, exclusive clade of their own. Most curious.
> I should note that my use of "croc" and "crocodiles" and
> "crocodylians" in my last post on this topic were drawn from
> an inflated sense of the use of "croc"
> for the Crurotarsi/Crocodylotarsi/Crocodylomorpha clades, and
> not from any special reference to the Crocodylia itself.
> In addition, I have received some comments on my regarding
> of the lack of availability of Nesbitt and Norell's name
> given the online publication. I have not, unlike for Pal.
> Elec. or Naturwiss., seen a statement regarding availability
> of online taxonomy. Jerry Harris has an application in
> _Bulletin of Zoological Nomenclature_ regarding the issue of
> digital nomenclature and its priority over press
> publications. The ICZN has made clear it's consideration of
> digital nomenclature, but not whether digital names have
> priority over later published _paper_ names, even if its the
> same name, making the date of those names questionable. The
> name *Dakosaurus andinensis* was digitally published only
> months before the publication finalized it, but which date is
> more valid?
> The issue is not clear, and thus the question should be
> validated before assuming, simply because the paper is
> online, that the taxonomy is valid. As it is, I will accept
> the press date when the paper is published as the valid issue
> of the name's availability, but not before, until the
> publisher says otherwise.
> Jaime A. Headden
> "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
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