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Re: Taxonomic levels in birds



>I think that there is a practical issue that debates on what birds "are" on
>this list have ignored.  This is the effect of trying to force an
>evolutionary tree, however derived, into the LInnaean system (or vice
>versa).  Doing so creates  a practical problem that will differ depending on
>your specialty.
>
[middle paragraphs deleted for space]
>
>In short, inconsistencies are almost forced upon us if the whole system is
>not to get so unwieldy as to be of no practical use. I have no solution for
>this, but it might shed some light on why some ornithologists are unhappy
>about saying birds "are" dinosaurs even though that is cladistically
>correct.  I don't hear people here arguing that all dinosaurs are
>crossopterygian fishes, but the  argument is identical.

You obviously haven't read much by basal tetrapod workers, then... :-)

The option that many systemicists have done is dump the outdated concept of
"rank" in taxonomy.  We can keep Piciformes and Phasanidae and Carinatae and
the like as labels for clades, but recognize that these clades are nested
within more inclusive clades such as Maniraptora, Archosauria, Diapsida,
etc.  Workers who specialize on "paraphyletic" groups are happy to do this,
but for some reason, those on the crown groups are less happy with the
situation...

Thomas R. Holtz, Jr.
Vertebrate Paleontologist
Dept. of Geology
University of Maryland
College Park, MD  20742
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Fax: 301-314-9661
Phone:301-405-4084