RE: true semilunates & carpometacarpi (was Caenagnathiformes)

["Ken Kinman" <kinman@hotmail.com>]

     Sorry if I confused you Tim.  :-)    Some non-maniraptors have fused 
carpal elements, and I am concerned about the possibility (however remote) 
that any of these could be confused with the fused carpometacarpi 
(containing "true" semilunates) of alvarezsaurians, avimimids, and 
pygostylians.
     Anyway, inserting the word "usually" into the wording of my preferred 
definition of "true" semilunate, we get:

     A distal carpal structure which (1) is enlarged so as to fully cap 
metacarpals I and II; (2) usually has a distinctive semilunate shape; and 
(3) has a pronounced trochlear groove on the proximal side.

     I would welcome any "constructive" suggestions on how this precise 
definition could be further improved.
             ----- Cheers,  Ken

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