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Re: (fwd) Mammals as a cause of Dinosaur extinction



In a message dated 97-12-19 04:08:40 EST, se1aard@itis.com writes:

<< Not disagreeing with what you are saying in general, but didn't the
 Phorusrhacids ("Fear Cranes", right?) actually have "wings" that had
 reverted into functional, three-clawed forelimbs?  Thereby greatly muddying
 the dinosaur/bird distinction (as if it wasn't enough already)?
  >>

These have been reported in the bird _Titanis walleri_, which is actually
great news for BCF. If large cursorial birds with volant ancestors that
presumably had the typically avian fused carpomanus could re-evolve some kind
of clawed forelimb, think of how much easier it would have been for a less
highly derived dino-bird to reacquire a clawed, grasping forelimb from an
archaeopterygid-like wing in which the carpus, metacarpus, and digits were
still separate.