Re: PARVICURSORINAE

["T. Mike Keesey" <tkeese1@gl.umbc.edu>]

On Thu, 26 Mar 1998, Tetanurae wrote:

> (Theoretically, Shuvuuia *could* be a parvicursorid mononykine
> alvarezsaurid). 

Yeeeee... cladistics may have done away with supergeneric ranks, but I
haven't seen any violations like this!

How about this:

Clearly _Alvarezsaurus_ is more primitive than any of the other creatures
in question. There is an advanced group consisting of the similar forms
_Mononykus_, _Shuvuuia_, _Parvicursor_, and maybe "Ornithomimus"
_minutus_. I have heard of no attempt to resolve the internal
relationships of this advanced group. From what I have heard,
_Patagonykus_ is somewhere between _Alvarezsaurus_ and the advanced group.
Thus:

|--_Alvarezsaurus_
+--+--_Patagonykus_
   +--advanced lineage

Here are the "family-level" names open to us, in order of priority:
those based on _Alvarezsaurus_
"     "     "  _Parvicursor_
"     "     "  _Mononykus_

TMK, only Mononykinae has been cladisitcally defined (+_Mononykus_,
+_Shuvuuia_).

Currently this group is called Alvarzsauridae, but originally
Alvarezsauridae only included _Alvarezsaurus_. I say, revert to that.
Define Alvarezsauria as all creatures sharing more recent ancestry with
_Alvarezsaurus_ than with (just to cover our butts): tyrannosaurs,
ornithomimosaurs, troodontids, oviraptorosaurs, therizinosaurs,
ornitholestids, dromaeosaurids, _Archaeopteryx_, enantiornithines,
hesperornithiforms, ichthyornithiforms, and neornithines.
The internal structure:

ALVAREZSAURIA
|--Alvarezsauroidea (+_Alvarezsaurus_, -_Parvicursor_)
|  +--_Alvarezsaurus_
+--Parvicursoroidea (+_Parvicursor_, -_Alvarezsaurus)
   |--_Patagonykus_
   +--Parvicursoridae (+_Parvicursor, -_Patagonykus_)
      |--_Mononykus_
      |?-"Ornithomimus" _minutus_
      |--_Parvicursor_
      +--_Shuvuuia_

If _Shuvuuia_ and _Mononykus_ turn out to share a clade exclusive of
_Parvicursor_, then that can be called Mononykinae.

Any problems with this scheme?

--T. Mike Keesey
tkeese1@gl.umbc.edu
DINOSAUR WEB PAGES -- http://www.gl.umbc.edu/~tkeese1/dinosaur/index.htm