I don't use FB or gmail, but a basic question first - has your park ever been linked to your FB account yet? If not then it is expected if you log in with FB "only" then it cannot find anything.
Try log in with gmail first so you can get into your park. Then log in to FB too and hopefully this will create the link. If it does, you should then be able to log in using FB only (without gmail).
For older dragons their dragon page should have the info. Bizurian contributes 4 elements to the breeding combination: cold, lightning, air and dark, so Sun is a possible breeding result.
Check the page: dragonvale.wikia.com/wiki/Rift_Dimension
Search for comment on October 20, 2017 by Nankiepooachoo, there is a diagram of the fastest way to locate yours.