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Re: DA reviews



Tim Williams (twilliams_alpha@hotmail.com) wrote:

<For the gazillionth time, no one has suggested that birds evolved *from*
deinonychosaurs, any more than humans evolved from chimps.  The two are proposed
to be sister groups.>

  To my knowledge, the lineage-segment advocates _do_ argue, as most
anthropologists apply the phylogeny, that chimps _did_ give rise to humans, as
much as australopithecines gave rise to hominines, because they are "obviously"
more primitive. At least Tim White's commentaries have applied a non-cladistic
theory to this affect, advocating a lineage-driven, pseudo-Linnaean style rather
than a cladistic perspective.

<The specialized pedal digit II is also seen in _Rahonavis_ (a bird!) and
troodontids.  _Microraptor_ has one too - and Feduccia suggests that
_Microraptor_ should be removed from the Dromaeosauridae!  [Says Feduccia: "In
addition, the recently described four-winged dinosaur from China (Xu et al.
2003 ) appears to be much more birdlike than dromaeosaurlike, and its supposedly
diagnostic dromaeosaur tail (also like that of a ramphorhynchoid pterosaur) and
claws bear little close resemblance to those of the typical dromaeosaurs such as
_Deinonychus_ and _Velociraptor_.]  Says who?

Dromaeosaurid-like tails are also seen in _Shenzhouraptor_/_Jeholornis_ (a
bird!!).>

  But not to such a degree that there is a "ramphorhynchoid" [sic, which I'd
always known was not a anagram -- my previosu use of this phrase was to point
out whose mispelling it had been] tail in *Rahonavis,* *Shenzhouraptor,* or
*Jixiangornis,* (I actually am coming to some disagreement that *Jeholornis* is
the same as *Shenzhouraptor,* based on some cranial and appendicular/pevlic
features that are inconsistent based on current material). Note also that the
previous author and Ruben et al. had also argued that *Rahonavis* was _not_ a
bird because of supposedly lacking a hypopubic cup and that the wings,
persistently argued for a few years though not currently applied, belonged to
*Vorona* instead.

  Cheers,

  Jaime A. Headden

  Little steps are often the hardest to take. We are too used to making leaps in
the face of adversity, that a simple skip is so hard to do.  We should all learn
to walk soft, walk small, see the world around us rather than zoom by it.

  "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)