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Re: Archaeopteryx or Velociraptor



DinosØMP <enrique@sn.no> wrote:

> It could actually be! But I've seen _many_ cladograms which lists 
> _Archaeopteryx_ AFTER Dromaeosaurs! If _Archaeopteryx_ is the 
> dromaeosaurs ancestor, I has to be listed as more primitive than the 
> Dromaeosaurids! (that's the way I would have done it!)

The order in which the groups in a cladogram are presented has nothing to
do with how "primitive" they are. In fact, cladograms by themselves do not
say anything about "primitive" vs. "advanced".

These three cladograms are essentially the same:

--+--Velociraptor
  +--+--Archaeopteryx
     +--modern birds

--+--Velociraptor
  +--+--modern birds
     +--Archaeopteryx

+--+--+--modern birds
   |  +--Archaeopteryx
   +--Velociraptor

What matters is which animal shares a more recent ancestor with modern
birds, not which is listed later.

--T. Michael Keesey
tkeese1@gl.umbc.edu
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