Eric Walker added 250 Million Years Ago, They Hibernated at the Bottom of the World - The New York Times and Lystrosaurus - Wikipedia to Lystrosaurus, and added Lystrosaurus to Lystrosauridae

Eric Walker added Lystrosaurus to Lystrosauridae, and added Lystrosauridae to Dicynodontia

Eric Walker added Lystrosauridae to Dicynodontia, and added Dicynodontia to Therapsida