HELP DESPERATELY NEEDED

[RaptorRKC@aol.com]

To all:

My sister -- who is, BTW, dinosaur-ignorant -- tells me that, as a pure fact,
birds ARE NOT a kind of dinosaur.  For example, Stegosaurus and Deinonychus
-- very dissimilar anatomically -- are both dinosaurs, according to her
"fact", but Rhea -- a bird that Deinonychus has more in common with than
Stegosaurus -- is NOT a dinosaur at all.  I would appreciate it if someone
could, in simplified terms, explain why birds are included in the Dinosauria
(in most cases, anyway).  Don't e-mail me telling me why birds AREN'T
dinosaurs ... that's not what I'm asking for!

Thanks,

Rachel Clark