How to use Artiodactyla in a sentence
The characteristics of camels and their systematic position are discussed under the headings Tylopoda and Artiodactyla.
The Perissodactyla have been brigaded with the Artiodactyla to form the typical group of the ungulates, under the name of Diplarthra, or Ungulata Vera, and the features distinguishing the combined group from the less specialized members of the order Ungulata will be found under the heading of that order.
The following are the leading characteristics by means of which the sub-order Perissodactyla is distinguished from the Artiodactyla.
These tiny animals, commonly known as mousedeer, are in no wise nearly related to the true deer, but constitute by themselves a special section of artiodactyle ungulates known as Tragulina, for the characteristics of which see ARTIODACTYLA.
As contrasted with the Perissodactyla living, and in a great degree extinct, Artiodactyla are characterized by the following structural features.Advertisement
Artiodactyla date from the Eocene period, when they appear to have been less numerous than the Perissodactyla, although at the present day they are immeasurably ahead of that group, and form indeed the dominant ungulates.
The primitive Artiodactyla thus probably had the typical number (44) of incisor, canine and molar teeth, brachyodont molars, conical odontoid process, four distinct toes on each foot, with metacarpal, metatarsal and all the tarsal bones distinct, and no frontal appendages.
In Anoplotherium, some of the species of which were larger than tapirs, there were either two or three toes, the latter number being almost unique among the Artiodactyla.
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.
For the genus Elotherium, of the Lower Miocene and Upper Oligocene of both hemispheres, which is often placed next the Suidae, see ARTIODACTYLA.Advertisement
Their lower articular surfaces, instead of being pulley-like, with deep ridges and grooves, as in other Artiodactyla, are simple, rounded and smooth.
The latter is represented by the Eocene Condylarthra, which undoubtedly gave rise to the Perissodactyla and Artiodactyla, and probably to most, if not all, of the other groups.
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.
By Professor Max Weber it is employed as a collective designation for these groups, together with the extinct Anthracotheroidea and Dichobunoidea; but its use seems best restricted to a general term rather than a definite systematic group. (See ARTIODACTYLA, PECORA, TYLOPODA.)
The typical ungulates are the members of the suborders Artiodactyla and Perissodactyla, in both of which the bones of the foot articulate with each other by means of groove-and-tongue joints, whence the name of Diplarthra (equivalent to Ungulata Vera), which has been proposed for these two groups collectively, as distinct from the other representatives of the order.Advertisement
As stated in the article Artiodactyla, these animals typify the family Suidae, which, with the Hippopotamidae, constitute the section Suina, a group of equal rank with the Pecora.
The earliest representatives of the Tylopoda according to Professor Scott is the Middle Eocene genus Homacodon, typifying the family Homacodontidae, which is regarded as the common ancestor of both Camelidae and Oreodontidae, with resemblances to the European Oligocene genus Dichobune (see Artiodactyla).