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Re: Youngest dino remains



In a message dated 3/19/99 7:20:32 PM EST, pharrinj@plu.edu writes:

<< Who cares whether the groups are extant or not?  There are a great many
 known fossil taxa (_Triceratops_, _Gastonia_, _Dicraeosaurus_, etc.) that
 are "manifestly not birds", yet fall inside your definition of birds.>>

We know very little about extinct groups, a lot more about extant groups. It
makes more sense to use higher-level classifications that are anchored to
extant groups than to extinct groups when possible. As a matter of fact, it is
>not at all< manifest that the genera you list aren't birds; they're certainly
more closely related to extant birds than any other extant taxa are. You might
find it interesting and insightful to think of them as large, very primitive,
heavy-bodied, quadrupedal birds.
 
<< As I have mentioned before, BCF is simply _speculation_ on the physical
 form and lifestyle of some undiscovered common ancestors--the very same
 common ancestors uncovered by cladistics and other phylogenetic methods. >>

BCF is no more speculative than any other hypothesis of bird origins, and it
has a great deal of evidence--anatomical, physical, and phylogenetic--that
supports it. More evidence, I assert, than any competing hypothesis.