NOTE: POLL HAS BEEN MOVED TO User blog:Peenut2k7/(POLL) The Grandest Of All Finales: Death of the Author, PLEASE VOTE THERE INSTEAD OF HERE
Well, I never thought I'd have to do this...!
Anyway, though most of us think that Petrie is a Pteranodon, readily available official pieces of material (DVDs for the series) identify him as Pterodactylus; specifically Pterodactylus elegans, which is now regarded as a species within Ctenochasma and not Pterodactylus. However, there are also materials available that classify him as Pteranodon; namely the Universal Kids website.
With all of this in mind
Poll will wrap up on the 10th.