Re: Hanson 2006, Mortimer, Baeker response

[Tim Williams <twilliams_alpha@hotmail.com>]

Nick Pharris wrote:

> There are those who would consider encoding relative rank in the ending on 
> the name a good and useful thing.

The problem is that, with phylogenetic definitions, the relative 'rank' (as 
implied by the suffix) has to be consistent with the definition.  If you 
want to encode relative rank, then clades ending in -oidea, -idae, -inae, 
-ini have to be defined in such a way that they they don't become more 
inclusive than clades of lesser or equal 'rank'.

For example, if we wanted to name and define a clade Microraptorinae, we 
would have to frame the definition such that Microraptorinae would never 
include Dromaeosauridae, Dromaeosaurinae or Velociraptorinae.  Similarly, 
Diplodocoidea, Diplodocidae, Diplodocinae, and Diplodocini must be defined 
such that (a) each is a subset of the one before (in terms of content); and 
(b) they cannot include clades of equal or greater 'rank' (as denoted by the 
suffix).  On the other hand, Diplodocimorpha is free to go wherever it 
wants, because it has no Linnaean baggage.

This isn't just a theoretical problem.  Senter (2004) discussed this problem 
with respect to dromaeosaurid nomenclature, when he wanted to name a new 
clade for _Microraptor_ and its closest relatives.  He studiously avoided 
naming his new clade either Microraptoridae or Microraptorinae, because he 
foresaw that changes in topology (i.e., relative position of _Microraptor_ 
vs _Dromaeosaurus_) could put Microraptoridae inside Dromaeosauridae - and 
he didn't want that.  Instead Senter opted for the name Microraptoria.  
Without a suffix to denote 'rank', Microraptoria can be above or below 
Dromaeosauridae and/or Dromaeosaurinae.  But Dromaeosaurinae has to be 
*within* Dromaeosauridae.

Cheers

Tim