Elasmosaurus n. : An extinct, long-necked, marine, cretaceous reptile from Kansas, allied to Plesiosaurus.

Example:
who were Elasmosaurus enemies?

Taxonomy
Elasmosaurus, plesiosaur, neck, Everhart, free encyclopedia, long neck, head and neck, lizard, body, the Academy, Academy of Natural Sciences of Philadelphia, prey, Late Cretaceous, genus, Kingdom, Phylum, Discovery, Edward Drinker Cope.

Defination from the web:
Elasmosaurus (pronounced /iːˌlæzmɵˈsɔrəs/; from Greek ελασμος elasmos 'thin plate' (referring to thin plates in its pelvic girdle) + σαυρος ... Elasmosaurus platyurus was described in March, 1868 by Edward Drinker Cope from a fossil discovered and collected by Dr. Theophilus Turner, a ...