Jurassic Marsh is the 14th world in Plants vs. Zombies 2. This world takes place during the Jurassic Era, long before the events of Frostbite Caves, where dinosaurs were still alive. Although the lawn is located in a marsh, water is not a relevant environment modifier in this world. However, water can be seen near the lawn. All the plants obtained in this world except for Perfume-shroom are "primal" versions of the Player's House plants. Dinosaurs are the gimmick and environmental modifier of this world. They do not act like typical zombies and are not classified as such since there is no such interaction between the dinosaurs and plants (except between Perfume-shroom). They, however, do interact with zombies of any type that passes by them. The dinosaurs are the raptor, Stegosaurus, pterodactyl, T. rex, and Ankylosaurus.
The Plants that you can obtained in this world (My Take): Primal Peashooter: Day 1 Primal Wall-nut: Day 4 Perfume-shroom: Day 8 Grapeshot: Day 11 Primal Sunflower: Day 17 Primal Potato Mine: Day 23 Cold Snapdragon: Day 30 Primal Rafflesia: 20 Seed Packets Timid Thorns: 15 Seed Packets Dino-Roar Grass: 20 Seed Packets Sugarcane Master: 20 Seed Packets Meteor Flower: 25 Seed Packets Cob Cannon: 40 Seed Packets