Styxosaurus
| Styxosaurus Temporal range: Late Cretaceous,  | |
|---|---|
| Holotype skull of Styxosaurus snowii | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Class: | Reptilia | 
| Superorder: | †Sauropterygia | 
| Order: | †Plesiosauria | 
| Family: | †Elasmosauridae | 
| Subfamily: | †Elasmosaurinae | 
| Genus: | †Styxosaurus Welles, 1943 | 
| Species | |
| Synonyms | |
| 
 | |
Styxosaurus is a genus of plesiosaur of the family Elasmosauridae. Styxosaurus lived during the Campanian age of the Cretaceous period. Three species are known: S. snowii, S. browni, and S. rezaci.