''Rhachiocephalus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

dicynodont Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typic ...

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

References

The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive
Dicynodonts Lopingian synapsids of Africa Fossil taxa described in 1898 Taxa named by Harry Seeley Lopingian genus first appearances Lopingian genus extinctions Anomodont genera {{anomodont-stub