Re: Dinosauria

[Mark Sumner <range@inlink.com>]

Saurischia@aol.com wrote:

> Traditionally, my understanding was that "dinosaurs" were extinct
> Archosaurian Diapsids, which would include Thecodonts, Pterosaurs,
> Saurischians, and Ornithischians, (and Placodonts?), excluding only the
> Crocodylia.  But am I to understand that birds, or more accurately,
> animals in the class Aves, are also members of dinosauria?  If dinosaurs
> are Archosaurs, and Archosaurs belong to the Diapsids, and Diapsids
> belong to the class Reptilia, how can this be?

Actually, I think you'll find a lot more people willing to class
Aves as dinosaurs than you will those willing to lump in Thecodonts
and Pterosaurs.  There has been a suggested rearrangement which
would place Dinosauria as a Superclass, with Aves a member therein.
It's far from universally accepted.

And I'm sure there are other schemes out there.  I've already shown
myself woefully ignoranr of the current state of such things in my
attempts to revive mammallike reptiles.  I'm no doubt out of date
on this one, as well.

Mark
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