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Rank taxonomy (was Re: Cladism (akin to masochism))



>   Are the terms Class, Order, Infraorder, etc. used in the clade world?

Some people have tried to reconcile Linnean ranks and cladistic groupings,
but they have run into problems (if Aves is a Class, than what about
Theropoda? Saurischia? Dinosauria? etc.).  There has been a move to drop
the Class, Order, Infraorder, etc. ranks, to make things simpler and to
reduce the number of names.  (Although cladism has been blamed for an
increase in the number of names, gradism created plenty of redundant names
[e.g., Family Archaeoptergyidae, Order Archaeopterygiformes, Subclass
Saururae, all of which contain only the species Archaeopteryx
lithographica] in order to satisfy all the 'appropriate' ranks).

>   And as long as I'm at it, is every line attached to a specific named node
>carry that name?

If a line attaches to the node, and that node has a name, than
(phylogenetically) the group represented by the line is a member of the
node, and so carries that name.  For example, if) there are the three names
"Thyreophora", "Marginocephalia", and "Ornithopoda" attached to the node
"Ornithischia", then thyreophorans, marginocephalians, and ornithopods are
all in the group Ornithischia.

                                
                 Thomas R. Holtz, Jr.                  Phone: 703-648-5280      
                 Vertebrate Paleontologist         Fax:    703-648-5420
tholtz@geochange.er.usgs.gov ------------>       th81@umail.umd.edu
U.S. Geological Survey          ------------->       University of Maryland
Branch of Paleontology & Stratigraphy ---->       Department of Geology
MS 970 National Center
Reston, VA  22092               ------------->        College Park, MD  20742
                                                          U.S.A.