Pteranodon *can* be mooched from Rudderfish.
Proof: http://puu.sh/meEAd/aee028e4f2...
As the chat log states, my Gathering Rate is 463 - 469 with my Rabbit Pies. I caught the Rudderfish around 3:00 PM Eorzean Time, and mooched it for the Pteranodon.
I tried mooching with Sky Faries... only got Cloud Riders, Rudderfish, and Star Faeries.
Red Balloons are the bait you want to use. Also, my Aetherical Reduction yielded a Dawnborne Aethersand and 46 Ice Crystals.