Philidor: No Class (was RE: Avian stem-group (was: BCF))

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

Philidor wrote:

> Now dinos are at a level with birds and reptiles.  

They are?  News to me.  I'm aware that Bakker proposed a "Class Dinosauria"
nearly twenty years ago.  Like the A-Team and the Rubik's Cube, the idea
caught on briefly, but I don't see anyone pushing it any more.  

> Problem is sentiment; why, do you know there are actually people who 
> want to classify birds under dinos, diminishing birds as a group, in 
> order to demand recognition that dinos have descendants?!

If I had a penny every time I heard this fatuous argument...

The problem is not "sentiment".  And it isn't a "problem".  Evolution put
birds *within* the dinosaurs, and any taxonomy that aims to reflect the
evolutionary history of a clade requires that this relationship be
recognized.  

Contrary to some assessments, the "birds-are-dinosaurs" phylogenetic
argument is not a poisonous plot to undermine the modern wonder that is the
Aves.  Really it isn't.  Rather, it's an attempt to articulate the
relationships that are inferred to exist among taxa without invoking
outdated notions of superiority (as the old-hat rank of "Class" denoted).

> Science doesn't work as sentiment.  Popularly and scientifically, 
> you've got your reptiles, you've got your birds, you've got your 
> dinos.  Pure logic and clear definitions always win out.

Scientifically????!!!!  Mr Philidor, you're drifting aimlessly in a Linnaean
universe.  You're conveniently forgetting that evolution blurs the
boundaries between groups (such as the Linnaean groupings of Aves and
Reptilia - and Bakker's concept of Dinosauria and Pterosauria), making any
distinction between related groups arbitrary once intervening taxa are
identified.

> Me, I think that Jefferson put his finger on the problem.  Remember, 
> he said he was once tempted to consider bones as evidence in 
> classification schemes, but it led only to arguments.  

Arguments?  For shame!!  I had some quaint idea that scientific questions
could be addressed by robust scientific debate.  I must say, I don't much
like your idea that we should always take the "easiest" route to
classification, irrespective of its scientific merit.  Might as well bring
back "Vermes" - that would at least alleviate the bother of trying to work
out the relationships of those pesky little wormy things.  

> The glance of the traveler on horseback is, as Jefferson said, the 
> exemplar of scientific classification at work.

The honorable Jefferson must have been drunk when he said that.  Or high.

> Aside from looking at most dinos with the technically apt, 'Those 
> are big honkin' bones', the use of bones is more abstruse than 
> it's worth.

I can't help but interpret this statement as a denigration of the field of
paleontology.  Are you perhaps posting to the wrong list?



Tim