Re: Ceratosauria vs. Neotheropoda?

[Tim Williams <tijawi@yahoo.com>]

Mike Taylor <mike@indexdata.com> wrote:

> In short: taste, judgement and an
> understanding of the historical
> background are required.  Any fool can define a clade,
> but doing it
> well is not as easy as it looks.  Caveat author!


Well said.  By the time PhyloCode is enacted, clade definitions should have 
arrived at the point that they ensure stability, as well as reflect historical 
usage.  

However, sometimes compromises have to be made: Dinosauria now includes birds 
(Aves), even though this would make Richard Owen spin in his grave.  But the 
nesting of birds inside Dinosauria is a phylogenetic reality, and so overrides 
historical usage.  Ditto for nesting tetrapods inside Osteichthyes, or putting 
mammals inside Therapsida.


Cheers

Tim