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Time for PT rules?

Since there are no hard and fast rules yet in phylogenetic taxonomy, we
have an excellent opportunity to set up a rational, well-defined system
here.  (Alas, I realize that paleontologists in particular are an
independent lot who tend to chafe at rules ;-)

Here are a few suggestions:

I am all in favor of using multiple exclusive anchor taxa in stem-based
definitions.  For instance, Ornithomimosauria could be defined as
"everything closer to _Ornithomimus_ than to _Troodon_ and closer to
_Ornithomimus_ than to _Tyrannosaurus_."  That way, the three arctomet
branches are kept separate even if their interrelationships get shuffled

Similarly, multiple *inclusive* taxa can be used in node-based
definitions.  That way, for example, the allosaurs, sinraptorids, and
carcharodontosaurs can all be kept in the Allosauroidea regardless of who
is closest to whom.

Perhaps there should also be a proviso for redefining groups in the light
of later discoveries.

We have a profusion of endings for names of taxa:  -morpha, -opsida,
-formes, -idae, -inae, -oidea, etc.  Perhaps some of these could be
restricted to stem-based or node-based usage, in the interest of clarity
and as an aid to memory.  For instance, -idae could be used for a
low-level node-based grouping, and -oidea for the stem-based grouping that
contains it.

(As much as I am in favor of abandoning Linnaean ranks, I still prefer to
have my -oideas above my -idaes above my -inaes.)

Finally, as a speaker of Greek and Latin, I am all in favor of quietly
correcting malformed names like "Ceratopsia."  (For those who might not
know, the -s at the end of _Ceratops_, the genus on which the name is
based, is not part of the stem, but merely a grammatical ending which
should be dropped before any other endings are added; hence, the name of
the group should be Ceratopia.)

The "i" in Maniraptora, BTW, is not a problem.  Although the stem for
"hand" in Latin is manu-, an unaccented "u" in the middle of a word was
commonly weakened to "i," which is why we have "manipulate" and not
"manupulate."  The problem with Maniraptora is the ending:  the plural of
"raptor" is "raptores," not "raptora," thus Maniraptores, not Maniraptora.  
Another way to solve this one is to make it Maniraptoria, which is
technically the neuter plural form of the adjective maniraptorius, meaning
"pertaining to those who snatch with the hands."

Much as I idolize Paul Sereno, his Latin is usually terrible.  I think all
bio and paleo types could benefit from a little Latin background.  It
probably wouldn't be too hard to cobble together an introductory course on
Greek and Latin for budding scientists who want to know what they're
talking about without having to read the _Gallic Wars_ or the _Aeneid_.

Respectfully yours,

Nick Pharris
Pacific Lutheran University
Tacoma, WA 98447