Deinosuchus reptile attacking a Corythosaurus dinosaur, illustration. Deinosuchus was a crocodile-like reptile that lived around 82 to 73 million years ago, in the Late Cretaceous. It is thought to have reached up to 12 metres in length. It was an ambush predator that hunted fish and dinosaurs. Deinosuchus fossils have been found in both freshwater and salt-water habitats. Corythosaurus was a duckbilled herbivorous dinosaur that reached lengths of 9 metres. It lived from around 77 to 75 million years ago.