Re: THE SAME PAGE

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-04-08 16:56:03 EDT, Tetanurae writes:

<< BACKGROUND: 
 Karhu and Rautian named Parvicursoridae in 1996 to house Parvicursor.  In
their diagnosis of the family, Mononykus olecranus is specifically excluded.
 PARVICURSORIDAE=={Parvicursor > Mononykus} Karhu and Rautian 1996
  >>

Now that I have a copy of the paper, thanks to Tracy Ford, and I've had a
chance to look it over, I can state absolutely that Karhu & Rautian >do not<
exclude _Mononykus_ from Parvicursoridae. Rather, they state at the end of the
second paragraph of their introduction, "In this work, we draw no conclusion
concerning the new taxon and _Mononykus_ at the family level because of
assence [sic] of comparable data characterizing these taxa."

The statement that Karhu & Rautian specifically exclude _Mononykus olecranus_
from membership in Parvicursoridae is >just plain wrong<. Indeed, much of
their paper is devoted to differentially diagnosing _Parvicursor_ from
_Mononykus_, necessitated by the similarities they describe between the
genera.

Parvicursoridae is not given a phylogenetic definition in the paper; it is
defined in a standard Linnaean manner and given the standard Linnaean rank of
family. In other words, it conforms to current ICZN nomenclatural conventions.
The only included member is _Parvicursor_, but no genera are specifically
excluded. The differences between _Parvicursor_ and _Mononykus_ as given in
the paper do not strike me as being of more than generic significance (using
the old Linnaean paradigm), and I would agree with the authors in their
discussion, namely, "The extent of the Parvicursoridae similarity to
_Mononykus_ exceeds that of any other family, included in the Maniraptora
_sensu_ Weishampel _et al._ (1990)."

So what the authors of the _Shuvuuia_ paper should have done is (1) lowered
the rank of Parvicursoridae to subfamily and called it Parvicursorinae; (2)
given this taxon a phylogenetic node-based definition using _Parvicursor_ and
_Shuvuuia_ (the two best-preserved genera in the subfamily); and (3) shown
that _Mononykus_ probably belongs to the same subfamily. Instead, they
unjustifiably ignored the existence of Parvicursoridae and created a new
taxon, Mononykinae, which has turned out to be a junior subjective synonym, at
the subfamily level, of the taxon they ignored. This sequence of errors has
confused rather than clarified the taxonomy of the group--as is demonstrated
by the lengthy sequence of dinosaur-list posts on this subject.