Prestige Quests
I came up with the idea of a prestige quest system, which will be unlockable after growing a dino to adult at least once on any server. Prestige quests will be lengthy quests that players attempt to slowly complete over long periods of time. This can give some form of "prestige XP", or a "prestige currency". These rewards can be used to unlock new, universal, cosmetics, model changes, subspecies, and even completley new species. For example, if one grinds out enough prestige quests on an Allosaurus, they unlock Saurophaganax, which is, essentially, an allosaurus with +attack and +defense, but a much slower speed. Not only will this incorporate more "MMO" elements into the game, but it will give players long term goals to grind for, that will keep them coming back for months at a time.