This lifeform has been extinct for over 20,000 years.

Elasmosaurus Family (Elasmosauridae) is known from the Cretaceous Period. The species in this family had very long necks with as many as seventy neck vertebrae. All known Elasmosaurs are extinct.

Plesiosaurs (Plesiosauria) were an ancient group of aquatic reptiles that originated in the late Triassic. The Plesiosaurs were large animals ranging in size from seven to almost fifty feet in length. Many Plesiosaurs had numerous neck bones and had very long necks. All Plesiosaurs are extinct.

Reptiles (Class Reptilia) are an ancient group of scaled  chordates. These scales may be permanently joined, as in the  turtles, or flexible, as in the snakes. Reptiles are land-based. Their eggs are laid on land and the young are air breathing.

Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.

Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.

Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.