Re: Cladograms (long)

[Tom Holtz <tholtz@geochange.er.usgs.gov>]

Having seen the cladograms you've posted, I'd suggest checking out any book
on phylogenetic systematics (aka cladistics) from a local college library.
You violate a basic tenent of cladistics: some of your "clades" are
explicitly monophyletic.  Let's take the first one:

>fig. A
>                                       Diapsida (see fig. B)
>                                      /
>                             Amniotea(
>                            /         \
>                  Tetrapoda(           "Andiapsida" (see fig. C)
>                 /          \
>          Verte-(            Amphibia
>         / brata \
>Chordata(         "Pisces"
>         \
>          "Protochordata"

[Actually, you've reconstructed the style of phylogeny used by Ernst
Haeckel in the late 19th century.]

Here's a standard version:

                                                        Diapsida
                                                      /
                            Sauropsida (Reptilia)
                                          /           \
                                        /              Anapsida
                                      /
                         Amniota(
                       /              \
                     /                  \
                   /                       Synapsida (Mammalia)
    Tetrapoda(
                   \
                     \
                       \
                         Lissamphibia

Or, in outline "shorthand":
Tetrapoda
        Lissamphibia
        Amniota
               Synapsida (crown group Mammalia)
               Sauropsida (crown group Reptilia)
                        Anapsida
                        Diapsida

Your "Andiapsida" includes anapsids (turtles & extinct kin) and synapsids
(mammals & extinct kin) - a non-monophyletic group.

Similarly, "Pisces" has been long abandoned by vertebrate systemicists,
since it includes hagfish and lampreys (outgroups to jawed vertebrates),
sharks, skates & rays (outgroups to bony vertebrates), and the bony
vertebates exclusive of the tetrapods.

In a cladogram, all the end units must be monophyletic.

                                
                 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.