I think that translates to Feed 50 Creatures on Isla Sorna. If so, you need to hatch and/or evolve 50 creatures. Place them on Isla Sorna (the new island) and feed them/level them up.
I’m pretty sure that when you evolve a create (2x 10s to a level 11x), that when you feed the newly evolved creature, it counts again.
Knowing that, if you hatch & evolve 34 commons, and merge them into 17x 11s (well 16, you don’t need the 17th), that would complete the mission.
You could also speed though by using one of the common dinos that have instant speed up and just hatch, feed 1x, sell, hatch, feed, sell, etc.
Translates to: Collect 50 creatures on Isla Sorna
I think you’re supposed to collect coins from dinosaurs in Isla Sorna. Click the compass that that says I. Sorna on the left.