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Re: Theropod Postcranial Isolation

Jaime wrote:

As an example of dry description, just read the short-form _Nature_ paper on
*Sinosauropteryx*. Indications of what is what is in the description are
lacking. Compare to Senter's thesis and resulting analysis of Diapsid phylogeny
and dromaeosaurid phylogeny, which provide figures of the character states in
his analysis, a practice I wish all systematists working in morphology would
use because it would implicitly indicate the variation from an immediately
visual experience, and allow comparative coding for the test of the analysis'
results. (like, what's the cut off between an "L"-shaped versus a "7"-shaped
lachrymal? Degree of angle? Measured from which point to which point across
which similarly measured axis?

I'm with you on two of your three points here:

(1) I also wish that more figures would be used in papers; and

(2) Characters defined with vague and ambiguous phrases require clarification -- e.g., it's not difficult to state an angle at which "L" becomes "7" shaped. However, having investigated characters of this ilk in the past (some such observations are in press), quantifying stuff like that can be equally problematic. If one defined the angle between "L" and "7" as, say, "less that 75 degrees," what happens when you have two specimens, one with a 76 degree angle and one with a 74 degree angle but that are thought otherwise to represent the same taxon? Individual variation can take its toll. Moreover, does _anything_ along a lineage that possesses a "greater than 75 degree" angle necessarily constitute a reversal, even if it's greater only by a couple of degrees? In the end, there's the actual wording and attendant quantification of a character, and then there's the "spirit" of the character, and coding based on pure numbers untempered by a broader understanding by the coder has the potential of producing false dichotomies.

What I do not agree with you on is the (probably unintentional) blaming on the researchers and authors of papers for not using figures. Don't blame us -- most of us would really LOVE to include more figures (as well as color figures, etc.). Blame instead the publishers that impose page limits and other restrictions for the sake of cost. Although like everything else, its costs have come down over the years, it's still prohibitively expensive to let everyone publish 100+ page, fully-illustrated monographs. So all us authors and researchers are forced, usually against our will, to remove informative details from our verbal descriptions and limit figures to just a few, really important ones. Well, OK...I should emend that statement by saying that if we want our papers published in widely-distributed, relatively easy-to-obtain, high ISI-ranked journals, then we have to make these sacrifices -- small press publications can more easily and inexpensively handle monographs and the like, but they rarely if ever attain the distribution levels and ISI rankings of the big journals. This has absolutely nothing to do with paleontology or science; it's pure capitalistic economics.

Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@hotmail.com

An expert is a man who has made all
the mistakes that can be made in a very
narrow field. -- Niels Bohr

After one look at this planet any visitor
from outer space would say "I want to
see the manager." -- William Burroughs