Re: Giant birds

[Dinogeorge@aol.com]

In a message dated 11/9/99 11:31:36 AM EST, tholtz@geol.umd.edu writes:

<< Something is a flightless bird when it is a) a bird (see above), b) does 
not
 fly, and c) is descendend from flying ancestors. >>

There's another definition of birds (one I particularly like because of its 
simplicity): all archosaurs closer to living birds than to living 
crocodilians (their closest living relatives), advocated by Peter Ax in 1989. 
By this definition, all dinosaurs become birds, as do pterosaurs (if you 
consider them to be ornithodiran archosaurs and not something more distant, a 
la Peters, for which the evidence is beginning to accumulate). For historical 
reasons, I would advocate using the term Thecodontia for the complementary 
taxon, all archosaurs closer to living crocodilians than to living birds.