Echiura

Kristian Fauchald Fauchald.Kristian at nmnh.si.edu
Thu Oct 28 16:20:33 EST 1999


	The Echiura is such a nice compact group so I do not believe they 
would ever become scattered all over the Annelida.  Thus, if the group is 
monophyletic, it is going to stay together no matter what; if it consists of 
two recognizable subunits, fine, if it does not, equally fine.  

	It is actually trivial whether the group is considered a phylum or a 
family:  Ranks such as these are artificial and represent a major problem if 
one starts to take them seriously.  The important point is that the group is 
clearly monophyletic:  There is a branch in any cladogram including these 
taxa that can be named Echiura, with all sorts of synapomorphies tied to it. 
I have no clear idea of what its sister-taxon would be.  I hope that will 
become clear as we study them, and the rest of the annelids.  

	I believe it is important that we understand the artificial nature of the 
ranks:  Taking them seriously leads to attempts at comparing them across 
the animal kingdom, and to all sorts of absurdities, such as naming certain 
features as family-level characters, genus-level characters etc.  

	The three gentlemen are eminent scholars on their groups, and I 
believe they should be happy the groups they study are so obviously 
monophyletic: For us working in a far messier world, this is one of the first 
goals to reach.    

Kristian Fauchald
<Fauchald.Kristian at NMNH.SI.EDU>


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