| Named By: | S. P. Modesto, B. S. Rubidge & J. Welman in 2003 |
| Time Period: | Unavailable |
| Location: | South Africa - Koonap Formation |
| Size: | Unavailable |
| Diet: | Herbivore |
| Fossil(s): | Partial remains |
| Classification: | | Chordata | Synapsida | |
| Also known as: | | Lanthanocephalus mohoii | |
Lanthanostegus is an extinct genus of non-mammalian synapsid.