We should bring the koolasuchus back. We would have to prevent it from being an invasive species, and from wiping out an entire species in one area. Research has shown that koolasuchus only ate animals that were a certain size; they were not pushovers. The koolasuchus needs to adapt to today's warming environment, so we would change some things up in its body and behavior. It would have stronger legs to walk on land to move around rivers when the heat dries them up. It would also have more muscle in its body to move faster, and be able to carry its body weight on land.

Since the koolasuchus had competition for food and space with crocodiles and alligators, the koolasuchus would live in a temperate rainforest were there are no crocodiles or any other modern animal that would wipe them out. As backup, just in case the crocodiles or koolasuchus move habitats, it would need to be prepared to coexist with the crocodiles. The koolasuchus would have thicker skin as armor to protect them from sharp teeth. 

One of the theories on why it went extinct was because the fish would eat the eggs, not allowing them to grow up. When we bring it back its eggs would blend into the environment. To prevent overpopulation, a koolasuchus will only lay a maximum of 150 eggs every spring; considering that not all will live to adulthood.