Dolichorhynchops is one of the most sucessful Plesiosaurs that lived during the time of the dinosaurs. It lived mostly in the western interior sea. Most of the year they spen time eating in the shallow water near to land. When the fish move out to deeper waters they follow them out to the deep through a mass migration. Young Dolichorhynchops stay close to older kin so that they would not be target for larger predators such as Mosasaurus and Cretoxyrhina.