Re: Opisthocoelicaudia (was Re: Titanosaurids)

[Dinogeorge@aol.com]

In a message dated 1/23/02 3:06:02 PM EST, TiJaWi@agron.iastate.edu writes:

<< Well, that's THREE characters (the first two of which may be functionally
 correlated) all of which can be readily interpreted as autapomorphies of the
 genus _Opisthocoelicaudia_.  There are many more characters that unite
 _Opisthocoelicaudia_ with the "typical" titanosaurids. >>

No, that's >dozens< of characters, since there are lots of dorsals, caudals, 
and sacrals that are different. The appendicular characters are minor and 
insignificant, and can easily come about through convergence, because all 
sauropods had to walk and carry great body mass. The big problem with 
cladistics is that there is no way to weight characters, so it becomes a 
phony one-character-one-vote situation. You can't equate a character that 
appears everywhere along the spine with a character that is a single small 
lump on a long bone. Cladistic analysis is not necessarily a democracy.