I received requests for the largest marine animal ever found. The Shonisaurus Sikanniensis was the largest marine reptile ever found. Some paleontologists have speculated that it could have reached lengths of more than 75 feet! It was related to the smaller Temnonodontosaurus pictured here. Sorry, but the Liopleurodon portrayed in walking with dinosaurs was exaggerated to monstrous proportions, but, I wouldn't want to swim with him around!