| Named By: | Geological Bulletin of China 24(9):785in794 in H. You, Q. Ji & D. Li in 2005 |
| Time Period: | Lower Cretaceous, 130 Ma |
| Location: | China |
| Size: | Holotype jaw reconstructed at a length of about one meter. Teeth measured at up to fourteen centimetres |
| Diet: | Herbivore |
| Fossil(s): | Partial jaw and some partial post cranial remains including cervical and dorsal vertebrae, ribs and a partial pelvis |
| Classification: | | Chordata | Reptilia | Dinosauria | Ornithishcia | Ornithopoda | Ankylopollexia | Styracosterna | |
Lanzhousaurus is a genus of dinosaur. Lanzhousaurus lived in the Gansu region of what is now China during the Early Cretaceous (Barremian). A partial skeleton has been recovered. It was described by You, Ji and Li in 2005 and the type and only species is Lanzhousaurus magnidens.
It is perhaps most notable for its "astonishingly huge teeth", among the largest for any herbivorous creature ever, which indicate it is a styracosternan iguanodont. The mandible, longer than one meter, suggests very large size for the animal.