Re: Nemicolopterus phylogeny

[Nick Pharris <npharris@umich.edu>]

Quoting "T. Michael Keesey" <keesey@gmail.com>:

> On Feb 13, 2008 8:49 AM, david peters <davidrpeters@earthlink.net> wrote:
> > I'm also one who cannot fathom how toothed spoonbilled pteros are 
> > derived from toothless spear-tipped pteros. There's got to be a 
> > better cladogram!
>
> CMIIW (I haven't read the paper yet), but couldn't _Nemicolopterus_'
> toothlessness simply be a convergent character?

[nods head vigorously]

(though I note that David's impression is mistaken; the cladogram given 
does not suggest that ctenochasmatids are derived from "toothless 
spear-tipped pteros")

But in the paper (2nd to last paragraph), the authors really do state:

"The phylogenetic position of Nemicolopterus crypticus suggests that 
the Ornithocheiroidea [including istiodactylids, ornithocheirids, and 
dsungaripterids] originated from crestless and toothless small 
insectivorous arboreal forms."

I *think* they were just being sloppy, but they also, bizarrely, say on 
p. 1985:

"The toothless condition is widespread among the Dsungaripteroidea 
[Ornithocheiroidea + _Nemi._ + _Nyctosaurus_]."

This is in the section discussing the phylogenetic placement of 
_Nemi._, and it reads as though it were justification for positing _N._ 
as a basal dsungaripteroid, which is rubbish unless you accept the 
proposition that Dsungaripteroidea is plesiomorphically toothless and 
that at least two sub-clades (Istiodactylidae + Ornithocheiridae and 
Dsungaripteridae) independently re-evolved teeth from a toothless 
condition.  I'd be loath to say it's *impossible*, but it seems pretty 
damned unlikely.

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Nicholas J. Pharris
Department of Linguistics
Max Planck Institute for Evolutionary Anthropology
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"Creativity is the sudden cessation of stupidity."
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