Where is the ‘Flight’ Gate Seal located

An open gate is one that you've found in-game and used a fragment to activate. Open gates save your progress as you roam about, and as you leave them to return to the Hisoria Crux.

Some portals have the close gate option. When you close a gate it resets all of the events and content there (other than collecting fragments and key items). This is so that you can re-play the area to make different story-altering live event choices. Those portals that do not have a close gate option don't have multiple story lines to choose from. You can still go back to collect missed items, but there's only one outcome from completing that time period.

This is what you're expected to do in order to experience each of the anomalies for a gate that has many of them. It is also how you earn the Anomalous trophy / achievement.

Here are my findings. Note that almost all of these are rare spawns and not always easy to tame. In my experience the Red Chocobo was the easiest to obtain and also the first you'll have access to.

     Name            Growth Type   Max  Obtained                      Note
COM  Chocobo         Late Bloomer   99  Tame - Archylte Steppe ???AF
     Red Chocobo     Late Bloomer   99  Tame - Archylte Steppe ???AF    *1
     Golden Chocobo  Well Grown     40  Found - A Dying World 700AF     *2
RAV  Blue Chocobo    Late Bloomer   99  Tame - Archylte Steppe ???AF    *3
MED  White Chocobo   Late Bloomer   99  Tame - Oerba 300AF
     Green Chocobo   Late Bloomer   99  Tame - Yaschas Massif 100AF
SEN  Silver Chocobo  Well Grown     40  Found - Academia 4XXAF          *4
SAB  Black Chocobo   Late Bloomer   99  Tame - Vile Peaks 10AF
SYN  Purple Chocobo  Late Bloomer   99  Tame - Bresha Ruins 300AF       *5

1. Seems to appear most often during sunny weather in grassy sections of the map (eastern half).
2. Found in a treasure chest.
3. On the western side of the map in the marshes. Weather doesn't seem to affect his appearance or spawn rate.
4. You have to use Moogle Throw on a green orb machine in Academy HQ. Keep tossing Mog in until he finds it.
5. Only spawns in the snowy areas (not the tunnels), and seems to be more often when you're near a Rambunctious Chocobo. Watch out for Tonberry while searching for Purple Chocobo.