Basically this mod would be a Prehistoric Mod. But not just like any prehistoric mod. First of all, the mobs spawn in SPECIFIC biomes, so you don't find them willy nilly or just use an incubator. You must HUNT for them. Let me introduce some item ideas:
This gear has ABOUT the same stats as leather armor. However, it increased your chance to find Dinosaur Eggs when mining.
Dinosaur Hunting Gear
Around the same stats as iron armor, wearing this gives the player a better chance of finding dinosaurs.