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 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.
Orders: Insectivora, Chiroptera, Dermoptera, Edentata (Sub-orders: Xenarthra, Pholidota, Tubulidentata), Rodentia (Sub-orders: Duplicidentata, Simplicidentata), Tillodontia, Carnivora (Sub-orders: Fissipedia, Pinnipedia, Creodonta), Cetacea (Sub orders: Archaeoceti, Odontoceti, Mystacoceti), Sirenia, Ungulata (Sub-orders: Proboscidea, Hyracoidea, Barypoda, Toxodontia, Amblypoda, Litopterna, Ancylopoda, Condylarthra, Perissodactyla, Artiodactyla), Primates (Sub-orders: Prosimiae, Anthropoidea).
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.
ARTIODACTYLA (from Gr.
As contrasted with the Perissodactyla living, and in a great degree extinct, Artiodactyla are characterized by the following structural features.
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.
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.
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.
(See Artiodactyla and Swine.) The teeth of the peccaries differ from those of the typical Old World pigs (Sus), numerically, in wanting the upper outer incisor and the anterior premolar on each side of each jaw, the dental formula being: i.
Pecus, cattle), a term employed - in a more restricted sense - in place of the older title Ruminantia, to designate the group of ruminating artiodactyle ungulates represented by oxen, sheep, goats, antelopes, deer, giraffes, &c. The leading characteristics of the Pecora are given in some detail in the article Artiodactyla; but it is necessary to allude to a few of these here.
For boss-footed, in reference to the cushion-like pads forming the soles of the feet), the scientific name of the section of ruminating artiodactyle ungulate mammals (see Artiodactyla) now represented by the Old World camels (see Camel) and the South American Llamas (see Llama) Characters.
Their lower articular surfaces, instead of being pulley-like, with deep ridges and grooves, as in other Artiodactyla, are simple, rounded and smooth.
Dier, &c., probably from a root dhus-, to breathe), originally the name of one of two British species, the red-deer or the fallow-deer, but now extended to all the members of the family Cervidae, in the section Pecora of the suborder Artiodactyla of the order Ungulata.