Re: Conodont elements

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[I wrote:]
> >bearing on their function".  One of the features that really puzzled 

> >me when I looked more closely at the reconstructions of Aldredge et 

> >al., 1987 for the ozarkodinid apparatus is how close together the 

> >individual S and P elements are positioned in bedding plane 

> >assemblages. 


...
|I am a late entry into this debate about close association of P and S 

|elements so have missed some of the info.

	Looking back on what I wrote, I probably could have been clearer.   
I was mainly referring to the close proximity of each of the S elements to  
eachother (for example), not how close the *sets* of elements (S and P)  
are.  The model presented by Aldridge et al., 1987 is an "exploded" model,  
so it does not clearly depict the distance between the elements, which is  
why I was quite suprised at how tight the arrangement was when I tried to  
accurately reflect the distances with a computer model.  The model on the  
cover of the April 27 _Nature_ does this much better.

|however----I have looked 

|at a large number of Oepikodus bedding plane assemblages basically of 

|two styles(1) loose partially disarticulated assemblages,mostly
|complete,and almost always with the M elements paired and similarly the 

|Pa, and Pb elements paired up. (2)tightly bundled assemblages S elements
|in the middle,with theM,P, grouped as Pa,Pb,M,(left) and Pa,Pb,M,(right) 

|on either side of the S element array.

	Sounds quite interesting.  When you say "Pa, Pb, M", is that the  
order from posterior to anterior, relative to the orientation of the S  
elements?  If not, that would be a surprise.  And when you say "either  
side", do you mean dorso-ventral, anterior-posterior, or left-right?  Have  
these assemblages been described/illustrated anywhere yet?  It sounds like  
you have a reasonable amount of the original geometry preserved (as  
opposed to coprolitic accumulations).



	-Andrew
	macrae@geo.ucalgary.ca
	home page: "http://geo.ucalgary.ca/~macrae/current_projects.html";