Re: Caenagnathiformes (toothlessness)

["Mickey_Mortimer11" <Mickey_Mortimer11@email.msn.com>]

Ken Kinman wrote-

>      And I was rather puzzled by Tim's post about Archaeopteryx and
> Deinonychus being so much alike.  I agree that they are alot alike, so why
> object to putting them into the same Class Aves?  I even put Deinonychus
in
> Order Archaeopterygiformes.

It was to illustrate how blurry the division between clades will become once
more fossils are found, and thus one of the faults of apomorphy-based
definitions.  Even assuming the semilunate of enigmosaurs and paravians is
easily distinguishable from the primitive condition (which probably isn't
that simple, given the unfused carpals in therizinosauroids, block-like
fused carpometacarpus in alvarezsaurids, non-semilunate form in
Protarchaeopteryx and Caudipteryx, etc.), we will undoubtedly find
intermediates that make the presence of this state hard to judge.

Mickey Mortimer