mitschlag
Posts: 236
Joined: Sep. 2006
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| Quote (Daniel Smith @ Feb. 16 2008,21:45) | mitschlag,
I'm sure this is not exactly what you're looking for either, but figure 3.37 (on page 134), gives an example of how Schindewolf used suture lines to draw similar conclusions about ammonoids to those he drew from the corals.
Each suture line depicted there represents 1) an ontogenetic developmental stage of two specific ammonoids, ('a' = the Permian adrianitid, and 'b' = the Permian stacheoceratid), AND, 2) a mature phylogenetic stage for various other forms of ammonoids, (with 'a6' and 'b3' being the mature suture lines for the adrianitid and the stacheoceratid respectively). He goes into some detail about this on the surrounding pages, (I also found the same figure repeated later in the book [pg. 209, fig. 3.75] with more explanation there.)
The arrow from 'a3' to 'b1' illustrates the ontogentic stage at which the stacheoceratid splits off from the adrianitid (they share the same first 3 stages -- 'a1-3' ). It's not as obvious to the untrained eye as it is from his coral diagrams, but if you study it closely, you can see that the same principle applies. |
Excellent. Now I get it! 
I think the issue of suture lines was tainted for me by the statement in Moyne and Neige: | Quote | | Suture line characters are not used in this analysis because of their high variability between the different species of each genus. |
So, I now see the parallel in Schindewolf's claims for corals and ammonoids: an ontogenetic switch.
Is that the gist of his saltationist hypothesis? It looks testable. Are there any molecular-genetic-devolopmental data pertaining thereto in the literature?
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"You can establish any “rule” you like if you start with the rule and then interpret the evidence accordingly." - George Gaylord Simpson (1902-1984)
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