Koolasuchus is a genus of dinosaur belonging to the family Chigutisauridae which belongs to the order of Temnospondyli. It lived approximately 125 to 100 million years ago, during the Early Cretaceous, in what is now Australia. The first fossils of Koolasuchus were discovered in the 1980s, providing paleontologists with valuable insights into this dinosaur. It was named after Lesley Kool.

Koolasuchus was a large, amphibian-like dinosaur, estimated to have reached lengths of around 5 to 6 meters. It possessed a flattened skull with wide jaws and numerous sharp teeth, indicating its adaptation for a piscivorous (fish-eating) or generalist diet. Its limbs were relatively short and robust, suggesting a semi-aquatic lifestyle.

Koolasuchus inhabited the ancient freshwater environments of the Early Cretaceous, which were characterized by lush forests, lakes, and rivers. Its amphibian-like characteristics, including the flattened skull, may have allowed it to forage in shallow water, capturing fish or other small aquatic prey. It likely had a specialized anatomy that enabled it to move between terrestrial and aquatic habitats.

Koolasuchus' amphibian-like characteristics suggest that it may have been capable of swimming and diving in search of prey. Its robust limbs and powerful jaws would have aided in capturing and consuming fish or other small aquatic organisms. It likely occupied a niche within the ancient freshwater ecosystems, adapting to exploit the resources available in both aquatic and terrestrial environments.