Marine reptiles are one of the three main focuses in Jurassic World Evolution 2. Marine Reptiles are reptiles that have their main habitat located in a body of water. Having first arose in the Permian period, they were the most numerous type of marine life throughout the Mesozoic period up to the mass extinction at the end of the Cretaceous. Though still surviving they were less common and include modern species of crocodiles, turtles, sea snakes and marine lizards.
In the game, players are tasked with bringing them back to life and ensuring their welfare within lagoons. The game launced with 6 seperate genera with 1 additional one being added in the Deluxe edition. As of December 2021, only 1 more marine reptile was added though the Early Cretaceous pack.
On August 25, 2000, while testing a prototype iron analyser, InGen reserchers descovered the DNA on a recently undiscovered Mosasaur species. Believing it the only way to be the only way of recreating marine reptiles, Dr. Henry Wu authosised the cloning of Jurassic World's first and only marine reptile. The recreated species was identified to be a much larger species, Mosasaurus maximus.
In 2016, a mercenary group returned to the lagoon to collect DNA from the Indominus Rex's skeleton only to be eaten afterward by the Mosasaur. The group also failed to close the lagoon's entrance to the Pacific leading to the Mosasaur to be allowed freewill to swim where she wishes.
By 2019, Isla Nublar's Mosasarus has been seen eating great white sharks in the Pacific Ocean.
The process of creating a marine reptile begins by sending out dig teams through the Expedition Center to dig sites across the world to recover their respective fossils. Recovered fossils are taken to the Science center where players can extract their DNA. Once the required amout of DNA has been extracted, it can be incubated and released into the park via the lagoon hatchery. Prior to the start of incubation, it is possible to modify a their skin, pattern and trait genes.
Marine reptiles behave towards other dinosaurs and the environment, with each type of genenra having a series of potential actions that define its behavior. Specific and General behavior statuses are shown through an indicator located at the top of their status bar and are often directly correlated with their requirements. Marine reptiles can be shown with a crown symbol if they are the alpha of their species in their lagoon.
Marine reptiles have a variety of species specific needs which must be satisfied in order to ensure their health and comfort are maintained. Unlike dinosaurs and flying reptiles they only require food which can be satisfied though shark or fish feeders. Different types of marine reptiles can variate slightly in terms of preferred enclosure size and whether they can tolerate other types of marine reptiles co-existing alongside them. For example, the Mosasaurus can tolerate a social group of 1 of its own species and other small marine reptiles. It can becomes agitated if it shares its enclosure with a large marine reptile like Tylosaurus, and soon will engage in either a death duel or territorial fight. These requirements are very similar with other marine reptiles on differing in the type of marine reptiles it can be enclosed in.