Cladogram of the order Artiodactyla showing the extant families and some selected extinct ones. Ruminantia includes the modern families Tragulidae, Giraffidae, Bovidae, Moschidae, and Cervidae, plus a number of extinct families. "Dichobunidae" is a paraphyletic assemblage of primitive taxa considered broadly ancestral to the later families. The interrelationships of the families reflect the "traditional" relationship based on morphology . Different arrangements based on molecular information [86, 87] would alter the placement of the Camelidae and Hippopotamidae but would make no difference to the arguments presented here concerning the Suoidea. The interrelationships within the Suidae are based on information in several studies [32, 67, 88, 89]. Note that only a couple of extinct suid subfamilies are shown, and that only extant genera of Suinae are shown. Thick, medium-thick and thin lines represent family or above, subfamily and genera, respectively.