Nicrosaurus is an extinctgenus of phytosaurreptile. Although it looked and probably lived like a crocodile, it was not closely related to these creatures, instead being a good example of parallel evolution. The main difference between Nicrosaurus (and all other phytosaurs) and real crocodiles was the position of the nostrils - Nicrosaurus's nostrils were placed directly in front of the forehead, whereas in crocodiles, the nostrils are positioned on the end of the snout.