Authentic real fossil tooth from the late Jurassic marine dinosaur Pliosaurus a marine reptile was more closely related to "saurians" (including crocodilians) and known for there large body size. Scientific classification Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: †Sauropterygia Order: †Plesiosauria Family: †Pliosauridae Clade: †Thalassophonea Genus: †Pliosaurus   |