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Re: *Gansus*

>What chance is there that *Gansus* actually belongs into Hesperornithes?

>As explained in their supplementary information, You et al. (2006) found 24 
>MPTs, in which *G.* was either outside of (Hesperornithes + Neornithes) or 
>closer to Neornithes than *Ichthyornis* or (as in the majority-rule consensus 
>tree in the paper itself) closer to (Neornithes + *Ichthyornis*) than to 

>Neither *Enaliornis* nor *Pasquiaornis* (nor, unsurprisingly, *Potamornis*) 
>were included; the only representatives of Hesperornithes are *Baptornis* and 
>*Hesperornis*. The supp. inf. states that *E.* was excluded because it shows 
>hesperornithean autapomorphies and would therefore predictably have come out 
>as >the sister-group to *Baptornis* + *Hesperornis* -- but I can't see why 
>that's an argument. It would after all have broken up the very long branch 
>that leads to (*B.* + *H.*); I wonder if we are seeing long-branch attraction 
>of (*B.* + *H.*). away from *G.*. The occurrence of MPTs where *G.* is outside 
>(Hesperornithes + Neornithes) shows that the phylogenetic position of (*B.* + 
>*H.*) is unstable.

    I think I can interject here (from being on vacation)...
    We simply used Clarke & Norell's matrix, with a few changes and additions 
-- we didn't try to change or add codings from anything we hadn't personally 
seen (well, Luis & Jingmai probably saw, and they did contribute to our changes 
for a few things), including _Enaliornis_.  This wasn't because we were/are 
lazy -- we are trying hard to get the funding we'll need to go see as many of 
these things in person as humanly possible -- but because our analysis was 
preliminary.  Like a lot of these kinds of phylogenetic analyses, we depended 
on other people's codings to be accurate and simply added our stuff to get a 
preliminary estimate of where _Gansus_ lay.  We had kind of predicted it would 
be fairly derived, based on its various characters, but were pretty surprised 
that it came out as advanced as it did -- that was the thing that made it 
_Science_-worthy.  If/when we get our funding, we will do a much more detailed, 
monographic osteology and comparison with lots of other things, and
 hopefully all will made much clearer, including whether or not _Gansus_ really 
is where we found it the first time (and yes, we have contemplated that it's a 
basal hesperornithean, specifically one that was still volant).  Rest assured 
also that a brand-new data matrix is being compiled, based in part on Clarke & 
Norell and others but with lots of new/changed characters and more accurate 
    We are aware of the various problems that convergence, long-branch 
attraction, etc. can have on an analysis with a taxon like _Gansus_; we're 
keeping all this in mind.  Still, it does beggar the question of exactly how 
much faith one can put in a computer-generated analysis when the human mind 
says something else...are we Borg or are we capable of abstracting beyond a 
bunch of statistics?  (Not an argument I'm going to have here...)
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
 and     dinogami@gmail.com
"Trying to estimate the divergence times
of fungal, algal or prokaryotic groups on
the basis of a partial reptilian fossil and
protein sequences from mice and
humans is like trying to decipher
Demotic Egyptian with the help of an
odometer and the Oxford English
               -- D. Graur & W. Martin
                    (_Trends in Genetics_
                    20[2], 2004)