Gigantosaurus
| Gigantosaurus Temporal range:  | |
|---|---|
| Part of the syntype series of G. megalonyx (from left to right: CAMSM J.29477, CAMSM J.29478, CAMSM J.29479 and CAMSM J.29483) | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Clade: | Dinosauria | 
| Clade: | Saurischia | 
| Clade: | †Sauropodomorpha | 
| Clade: | †Sauropoda | 
| Genus: | †Gigantosaurus Seeley, 1869 | 
| Species: | †G. megalonyx | 
| Binomial name | |
| †Gigantosaurus megalonyx Seeley, 1869 | |
Gigantosaurus (from Ancient Greek γίγας (gígas) 'giant' and σαυρος (sauros) 'lizard') is a dubious genus of Sauropod dinosaur from the Late Jurassic Kimmeridge Clay Formation of England. The type species, Gigantosaurus megalonyx, was named and described by Harry Govier Seeley in 1869.