RE: Yet Another FAQ: phylum, order, family

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Mike Taylor

> The second and more far-reaching innovation was the introduction of
> higher-level groupings than the genus. In Linnaeus's original system,
> genuses

genera


> For example, the phylum Vertebrata, the vertebrates, is a part of
> the animal kingdom.

Vertebrata is not a phylum; it is traditionally a subphylum within Chordata
(along with Cephalochordata and Urochordata).

>       Order
>       Parvorder
>       Nanorder
>       Hyporder
>       Minorder
>       Suborder
>       Infraorder
>       Gigafamily
>       Megafamily
>       Grandfamily
>       Hyperfamily
>       Superfamily
>       Family

There are a large number of other ranks proposed above this.  I suggest
checking out some classic works (like Matthew's classification of mammals)
for stuff between the "class" and "subspecies".  Additionally, the breakdown
of units is different between traditional zoological and botanical
subdivisions.

Incidentally, the suffixes added to various ranks within Animalia are not
standardized for taxa above the family level.  See many previous discussions
in the DML archive: for example, how about
http://www.cmnh.org/fun/dinosaur-archive/1997May/msg00421.html.

> This minimal
> approach is particularly popular in the cladistics community, perhaps
> in part because the trees generated by cladistic methods have far too
> many nodes, and change far too often, to be amenable to labelling
> with ranks.

Also from the recognition that there is no operational metric or system to
determining if two taxa differ "at the family level" versus "at the
superfamily level" or whatever; and the problem of people recognizing
equivalence of "rank" across taxa (i.e., is Ostreidae (oysters) somehow
equivalent to Alligatoridae and these two to Archaeopterygidae?).

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796