From Wiki:
The payoff.
As a kid whose life revolved around dinosaurs, this is news to me as well. And you can't count the ichthyosaurs, plesiosaurs and mosasaurs? I say let 'em all in.
And the reason I didn't take part in this draft is because if I can't have my three-horned n*gga, and I knew he was going to be taken early, then my ceratopsid posse would be without a leader.
Here is the breakdown of Archosauria that they have at Wiki. Pterosaurs are closely related to dinosaurs, but they aren't dinosaurs themselves. Birds however are, but I think everyone here rightfully assumes that we are excluding birds with regards to this draft. Otherwise I would have already taken Archaeopteryx.
As for mosasaurs, etc., they are pretty distantly related and have more in common with modern lizards and snakes than they do dinosaurs (well besides ichthyosaurs which are a bit different, and are a bit of a mystery). Crocodiles are actually closer to dinosaurs (in that they are both archosaurs) than those sea reptiles.
EDIT: It didn't show up right, but here is the link.
http://en.wikipedia.org/wiki/Archosaurs
It is at the very bottom of the page.