THE SAME PAGE

[Tetanurae <Tetanurae@aol.com>]

Recently on this list, there has been debate between myself, George Olshevsky,
and now Jon Wagner about the Mononykinae, Parvicursoridae and subjects of
priority.  It occured to me that we were talking about entirely different
things here.

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

Subsequently, Chiappe, Norrell and Clark (1998) named Mononykinae as a taxon
that housed Mononykus, Shuvuuia and Parvicursor.
MONONYKINAE=={Mononykus + Shuvuuia + Parvicursor} Chiappe et al 1998

GEORGE'S POSITION:
Any taxa with the endings -oidea, -idae, -inae, and -ini belong to
superfamilies, families, subfamilies, and tribes respectively, and thus fall
within the guidelines of the ICZN.  Since Mononykinae includes Parvicursor,
and the Parvicursoridae was named first, Mononykinae must become a junior
subjective synonym of Parvicursorinae because it was named first.  Simple, and
correct, according to Linnean standards (and thus ICZN standards) of
classifying and naming things.

JON AND PETE'S POSITION:
Parvicursoridae was defined to specifically exclude Mononykus from its
membership, and the definition has not specifically been changed by either
Karhu and Rautian or Chiappe, Norrell and Clark, so the definition sticks.
Parvicursoridae is a stem-based clade within the Mononykinae node.  Cladistic
methodology does not recognise ranks such as family or subfamily since they
have no real scientific meaning.  Retention of the original definitions should
be sought after since it avoids future confusion.

COMMENTARY:
Indeed, at its heart, this debate is over cladistics and linnean systems of
taxonomy (even if none of us knew it at the start).  One is left asking
though, what is a "family"?  It is actually a question I ask creationists
quite often.  They claim that the so called Cambrian Explosion saw the
appearance of 100s of new phyla in a short time (actually close to 200 million
years).  The obvious question is "what's a phylum?" which of course has no
quantitative answer.  Linnean ranks are subjective constructs as everyone here
knows, with no real scientific meaning and should be abbandoned as soon as
humanly possible (actually, they should have been abbandoned with Lamarck and
Darwin.....).

Peter Buchholz
Tetanurae@aol.com

"Terence: J'accuse!"