RE: Kileskus and Proceratosauridae

[Jaime Headden <qi_leong@hotmail.com>]

David Marjanovic wrote:

<What do you mean by "singular"? Does "a singular structure" mean 
"the same taxon"?>

  A set, rather, or any formalized definition of a group of OTU's. Group, Set, 
Taxon, etc. However, Structure in this case is a reference to the variations of 
portions of a tree which can be set aside as taxa.

  On to the greater point.

  The definitions for Monophyletic and Clade in the Phylocode glossary at 
http://www.ohio.edu/phylocode/glossary.html are virtually synonymous, which 
makes them virtual tautologies. Note that when I used that term, when Mike 
replied he passed the use of the term without comment, and when you replied to 
him to elaborate on his response to me, you also quoted it and passed on it, so 
the use of theterm being at issue is interesting. In accordance with the 
definition of a tautology ("needless repetition of an idea, esp. in words other 
than those of the 
immediate context, without imparting additional force or clearness, as 
in “widow woman.” see http://dictionary.reference.com/browse/tautology?r=75), 
one would argue that the phrase "monophyletic clade" is not in the strictest 
sense a tautology, but that was the word that Averianov et al used nonetheless 
(I swear I didn't make it up!). But they are redundant, and it makes me wonder 
whether the term "clade" is not more useful than the definition provided 
earlier.

  This does interest me further, though. What are the original historical uses 
of the phrase "clade" that renders classic forms such as Reptilia sensu 
Linnaeus NOT monophyletic and therefore not clades? I.E., why does "Clade" 
render to us a definition that is synonymous with "monophyletic," and also why 
are we not also using "holophyletic"?

Cheers,

Jaime A. Headden

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