Polymorph Question

[Cornellius Aggredor]

I am curious which polymorph spell I would use to turn in to a Wyvern.

A Wyvern is not a chromatic or metallic dragon, so that spell is out. Is there another spell out there that covers just a dragon of no other type like a wyvern is?

[Alchemist 23]

There are these

http://www.d20pfsrd.com/magic/all-spells/f/form-of-the-exotic-dragon/

http://www.d20pfsrd.com/magic/all-spells/f/form-of-the-alien-dragon/

But no Wyvern that I know of. Would a Space Dragon work?