Re: STEMS AND NODES

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-04-07 00:51:11 EDT, Tetanurae writes:

<< No it isn't.  Mononykinae INCLUDES Mononykus, Parvicursoridae EXCLUDES
Mononykus.  The simplist  thing to do would make Parvicursoridae a stem within
Mononykinae which is a node. >>

I don't have my copy of Karhu & Rautian handy, so I'll have to take your word
for it that their definition for Parvicursoridae explicitly excludes
_Mononykus_. This notwithstanding, you can't >include< Parvicursori-anything
within Mononyki-anything, because Parvicursori-anything has priority over
Mononyki-anything. Least of all can you include a family Parvicursoridae
>within< a subfamily Mononykinae as you suggest.

So--you can have a subfamily Mononykinae alongside a subfamily
Parvicursorinae, but the family they're both subfamilies of must be named
Parvicursoridae, not Mononykidae, because the family-level Parvicursori-
anything was named earlier. There is nothing in the ICZN about definitions of
taxa, only about what names are to be applied to which taxa--and this is done
by priority and inclusion.

So let me go over this again, re-e-al slo-o-ow:

In the paper, the authors have grouped _Mononykus_, _Shuvuuia_, and
_Parvicursor_ in the same subfamily. They have given this subfamily the name
Mononykinae. This is incorrect; they should have used the available name
Parvicursorinae, which has priority for any family-level taxon that includes
the genus _Parvicursor_. Or they should not have grouped _Mononykus_ with the
others, so as to follow the definition given by Karhu & Rautian for
Parvicursoridae and allow the names Parvicursoridae, Parvicursorinae, and
Mononykinae to have separate existences. By not doing the latter, they have
implicitly redefined the family Parvicursoridae to include _Mononykus_.

Don't like this? Change the rules. Formally.