Re: Applying Sereno's definitions to Neotetanurae: Part 1 & 2

["Jaime A. Headden" <qilongia@yahoo.com>]

Mickey has performed a very good review of how applying many definitions to
many topologies may require certain inclusive or exclusive specifiers to
maintain typical topologies. I have one further issue with this I think should
be addressed, in two parts:

A) The topologies range the spectrum from massive multi-taxon, multi-character
studies, such as the TWG analyses of Xu et al., Makovicky et al., etc., and
those of Holtz and Sereno, which have sampled a broader range of theropods than
the often coelurosaur-only ones of the TWG studies, or the
non-coelurosaur-specific analyses of Allain, Rauhut, etc. Some studies are so
brief or small that their use in creating a sampling range is virtually
useless, except in a historical point. Others, such as that of Martin, 1997,
have issues with the way the analysis was run or the character sampled,
indicating a flaw on the philosophy of the analysis, as he seems not to have
fully understood the process or the principles behind rooting and sampling.
Others have presented a selected tree, and others still have presented largely
only concensus trees. These afford us the ability to pare from history the
likely analyese closer to the truth. In sampling those analyses of the last,
say, 5 years, where complexes of characters and taxa pass the 300 and 50 mark,
respectively, we begin perhaps to get a better sense of sampling in which to
review our applications of definitions.

B) In the end, though, we are still applying definition ideas on the basis of
taxonomic baggage. If all taxa are equal, then there is no real issue (or
should not be) if Oviraptoridae includes Tyrannosauridae, if they are so
defined in a topology to be such. If this happens, the problem is not in the
phylogeny or the application of the names, but in the philosophy of what these
-idae or -inae names would mean to us. This is unneccessary baggage that
phylogenetic nomenclature would have us step away from. Senter provided a
rather distinct example of thinking outside the box in naming Microraptoria for
a clade that was essentially in a broad definition of Dromaeosauridae, which
led to Makovicky et al. to thinking this name was Microraptorinae, which is a
lapsus calami, not a new name, on their part (Makovicky, pers. comm.). This is
just one example of baggage such names give us. One way to avoid this, perhaps,
is dispose of those terms which hold baggage altogether, such as any taxon name
having a fundamental -idae or -inae structure. The crocodylian *Procaimanoidea*
is a "genus" of alligatorid, not a superfamily, and holding onto this baggage
would only lead to further confusion if any were to name a group under ICZN
provisions in which *Procaimanoidea* were to be included in an exclusive
Family-ranked taxon, as this will form a Procaimanoididae, Procaimanoidoidea,
etc., and perhaps even cause confusion if (now that the ICZN does not mandate
revision of past names to agree with correct current Latinization). Discarding
such baggage will open space for us to define taxa, name them, and such. If we
wish a certain name to apply to a certain concept, then define it as such, the
nominae ending in -idae would just confuse this issue.

  Many thanks to Mickey for furthering this fruitful discussion. If we are able
to find a decent set of phylogenies and study on ornithischians to found decent
definitions to reflect use, we should also bear this in mind, as for any group
of dinosaur or animals those who would read this could consider.

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


        
                
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