Eric Walker added Why are ungulates classified by toe parity? : askscience to Artiodactyla and Perissodactyla

Eric Walker added Rhinocerotoidea to Ceratomorpha, and added Ceratomorpha to Perissodactyla

Eric Walker added Indricotheriinae to Hyracodontidae, and added Hyracodontidae to Perissodactyla

Eric Walker added a number of topics and a number of links to Mammalia, and added Mammalia to Mammaliaformes

Eric Walker added Equus to Equidae, and added Equidae to Perissodactyla

Eric Walker added Hyracodontidae, Ceratomorpha and Equidae and Why are ungulates classified by toe parity? : askscience to Perissodactyla, and added Perissodactyla to Mammalia