Re: Benton and Kinman (long)

["Ken Kinman" <kinman@hotmail.com>]

Thanks David,
    Benton's 1997 classification is a valiant effort to store cladistic 
information, while at the same time recognizing some paraphyletic groups.  
He obviously recognizes Crocodylia sensu lato and separates Aves from 
Reptilia.  But as much as admire his effort, it is still too messy (and 
listing a Superclass among a list of Orders is a little confusing---although 
I clearly understand why he did so):

Infraclass Rhipidistia
 Order Porolepiformes
 Order Rhizodontiformes
 Order Osteolepiformes
 Order Panderichthyida
 Superclass Tetrapoda

    In my 1994 classification, I recognized the same clade informally 
through a code sequence within Class Sarcopterygea (an abbreviated version 
as follows, showing how my markers differ from his):

5  Sarcopterygea
    1  .....
         etc.
    4  Porolepiformes
    5  Osteolepiformes
    6  Rhizodontiformes
    7  Panderichthyiformes
    8  {{Amphibea}} (thence to Reptilea,
         Avea and Mammalea) (= Tetrapoda)

_1_ Amphibea
     1   Ichthyostegiformes
         ....etc.
     2D  Diadectiformes
     2E  {{Reptilea}} (thence to Avea
           and Mammalea) (= Amniota)
     3   Aistopodiformes
         ....... etc.

   Note that I have dropped "rank" names by completing the trend toward 
standardized endings above family level---but this is very controversial, 
and the system works using the names with traditional endings (Mammalia, 
Aves, etc.), so don't let that put you off too much (I still use Mammalia 
and Aves in my day-to-day correspondence, but standardized endings may catch 
on in the future).
   By the way, the clade Sarcopterygea 5-8 is what some cladists call 
Tetrapodomorpha, and this same coded clade will remain even if 
Rhizodontiformes split off before Osteolepiformes (I will just have to 
switch the order of those two Orders if that topology is confirmed).
   Anyway, Benton is trying to accomplish the same thing I am, but using 
(IMHO) old-fashioned intermediate ranks in a manner somewhat similar to the 
strict cladist McKenna (in mammalian classifications).  Benton is a great 
improvement over McKenna, but still a little too messy for my tastes.  If 
you don't like my approach, I very, very highly recommend the way Benton 
does it.  Whether Benton chooses to adopt any of my conventions in future 
classications remains to be seen, but we obviously share very similar 
Ashlockian (centrist) tendencies.
             ------Ken Kinman

_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp