The Tragulidæ are a group of small, hornless, deer-like animals, with tusks in the upper jaw, and having some structural affinities with the camels. The musk-deer was formerly classed in this family, which it resembles externally; but a minute examination of its structure by M. Milne-Edwards, has shown it to be more nearly allied to the true deer. The Chevrotains, or mouse-deer, Tragulus (5 species), range over all India to the foot of the Himalayas and Ceylon, and through Assam, Malacca, and Cambodja, to Sumatra, Borneo, and Java (Plate VIII., vol. i. p. 337). Hyomoschus (1 species), is found in West Africa.
Extinct Tragulidæ.—A species of Hyomoschus is said to have been found in the Miocene of the South of France, as well as three extinct genera, Dremotherium (also found in Greece), with Lophiomeryx from the Upper Miocene, said to be allied to Tragulus; and Amphitragulus from the Lower Miocene, of more remote affinities, and sometimes placed among the Deer. There seems to be no doubt, however, that this family existed in Europe in Miocene times; and thus another case of discontinuous distribution is satisfactorily accounted for.
Family 50.—CERVIDÆ. (8 Genera, 52 Species.)
| General Distribution. | |||||
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| Neotropical Sub-regions. | Nearctic Sub-regions. | Palæarctic Sub-regions. | Ethiopian Sub-regions. | Oriental Sub-regions. | Australian Sub-regions. |
| 1. 2. 3 — | 1. 2. 3. 4 | 1. 2. 3. 4 | — — — — | 1. 2. 3. 4 | 1 — — — |
The Cervidæ, or deer tribe, are an extensive group of animals equally adapted for inhabiting forests or open plains, the Arctic regions or the Tropics. They range in fact over the whole of the great continents of the globe, with the one striking exception of Africa, where they are only found on the shores of the Mediterranean which form part of the Palæarctic region. The following is the distribution of the genera.
Alces (1 species), the elk or moose, ranges all over Northern Europe and Asia, as far south as East Prussia, the Caucasus, and North China; and over Arctic America to Maine on the East, and British Columbia on the west. The American species may however be distinct, although very closely allied to that of Europe. Tarandus (1 species), the reindeer, has a similar range to the last, but keeps farther north in Europe, inhabiting Greenland and Spitzbergen; and in America extends farther south, to New Brunswick and the north shore of Lake Superior. There are several varieties or species of this animal confined to special districts, but they are not yet well determined. Cervus (40 species), the true deer, have been sub-divided into numerous sub-genera characteristic of separate districts. They range over the whole area of the family, except that they do not go beyond 57° N. in America and a little further in Europe and Asia. In South America they extend over Patagonia and even to Tierra del Fuego. They are found in the north of Africa, and over the whole of the Oriental region, and beyond it as far as the Moluccas and Timor, where however they have probably been introduced by man at an early period. Dama (1 species), the fallow deer, is a native of the shores of the Mediterranean, from Spain and Barbary to Syria. Capreolus (2 species), the roe-deer, inhabits all Temperate and South Europe to Syria, with a distinct species in N. China. Cervulus (4 species), the muntjacs, are found in all the forest districts of the Oriental region, from India and Ceylon to China as far north as Ningpo and Formosa, also southward to the Philippines, Borneo, and Java. Moschus (1 species), the musk-deer, inhabits Central Asia from the Amoor and Pekin, to the Himalayas and the Siamese mountains above 8000 ft. elevation. This is usually classed as a distinct family, but M. Milne-Edwards remarks, that it differs in no important points of organisation from the rest of the Cervidæ. Hydropotes (1 species) inhabits China from the Yang-tse Kiang northwards. This new genus has recently been discovered by Mr. Swinhoe, who says its nearest affinities are with Moschus. Other new forms are Lophotragus, and Elaphodus, both inhabiting North China; the former is hornless, the latter has very small horns about an inch long.
Extinct Deer.—Numerous extinct species of the genus Cervus are found fossil in many parts of Europe, and in all formations between the Post-pliocene and the Upper Miocene. The Elk and Reindeer are also found in caves and Post-pliocene deposits, the latter as far south as the South of France. Extinct genera only, occur in the Upper Miocene in various parts of Europe:—Micromeryx, Palæomeryx, and Dicrocercus have been described; with others referred doubtfully to Moschus, and an allied genus Amphimoschus.
In N. America, remains of this family are very scarce, a Cervus allied to the existing wapiti deer, being found in Post-pliocene deposits, and an extinct genus, Leptomeryx, in the Upper Miocene of Dakota and Oregon. Another extinct genus, Merycodus, from the Pliocene of Oregon, is said to be allied to camels and deer.
In South America, several species of Cervus have been found in the Brazilian caves, and in the Pliocene deposits of La Plata.
It thus appears, that there are not yet sufficient materials for determining the origin and migrations of the Cervidæ. There can be little doubt that they are an Old World group, and a comparatively recent development; and that some time during the Miocene period they passed to North America, and subsequently to the Southern continent. They do not however appear to have developed much in North America, owing perhaps to their finding the country already amply stocked with numerous forms of indigenous Ungulates.