The last section of the Artiodactyla is that of the Suina, represented at the present day by the pigs (Suidae), and the hippopotamuses (Hippopotamidae), and in past times by the Anthracotheriidae, in which may probably be included the Elotheriidae.
The ancient Greeks and Romans kept in captivity large numbers of such animals as leopards, lions, bears, elephants, antelopes, giraffes, camels, rhinoceroses and hippopotamuses, as well as ostriches and crocodiles, but these were destined for slaughter at the gladiatorial shows.
The collection is not usually very rich in species, but there have been great and long-continued successes in the breeding of large animals such as hippopotamuses, lions and antelopes, and a very large business is done in domesticated birds, water-fowl and cage birds.
The Artiodactyla are the only group of ungulates known to have been represented in Madagascar; but since both these Malagasy forms - namely two hippopotamuses (now extinct) and a river-hog - are capable of swimming, it is most probable that they reached the island by crossing the Mozambique Channel.
The pigs (Suidae) and the hippopotamuses (Hippopotamidae) are essentially Old World groups, the former of which has alone succeeded in reaching America, where it is represented by the collateral branch of the peccaries (Dicotylinae).
Hippopotamuses, on the contrary, are now exclusively African, although they were represented in tropical Asia during the Pliocene and over the greater part of Europe at a later epoch.