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The genus Capra consists of several sub-groups which have been named as genera, but it is unnecessary here to do more than divide them into "Goats and Ibexes" on the one hand and "Sheep" on the other—each comprising 11 species. The former range over all the South European Alps from Spain to the Caucasus ; to Abyssinia, Persia, and Scinde; over the high Himalayas to E Thibet and N. China; with an outlying species in the Neilgherries. The latter are only found in the mountains of Corsica, Sardinia, and Crete, in Europe; in Asia Minor, Persia, and in Central and North-Eastern Asia, with one somewhat isolated species in the Atlas mountains; while in America a species is found in the Kocky Mountains and the coast range of California, Ovibos (1 sp.), the musk-sheep, inhabits Arctic America north of lat. 60; but it occurs fossil in Post-glacial gravels on the Yena and Obi in Siberia, in Germany and France along with the Mammoth and with flint implements, and in caves of the Eeindeer period; also in the brick earth in the south of England, associated with Rhinoceros megarhinus and Elephas antirptus.
Extinct Bovidas.—In the caverns and diluviums of Europe, of the Post-Pliocene period, the remains are found of extinct species of Bos, Bison, and Capra; and in the caverns of the south of France Bupicapra, and an antelope near Hippotragus. Bos and Bison also occur in Pliocene deposits. In the Miocene of Europe, the only remains are antelopes closely allied to existing species, and these are especially numerous in Greece, where remains referred to two living and four extinct genera have been discovered. In the Miocene of India numerous extinct species of Bos, and two extinct genera, Hemibos and Amphibos, have been found, one of them at a great elevation in Thibet. Antelopes, allied to living Indian species, are chiefly found in the Nerbudda deposits.
In North America, the only bovine remains are those of a Bison, and a sheep or goat, in the Post-pliocene deposits; and of two species of musk-sheep, sometimes classed in a distinct genus Bootherium, from beds of the same age in Arkansas and Ohio. Casoryx, from the Pliocene of Nebraska, is supposed to be allied to the untelopes and to deer.
In the caves of Brazil remains of two animals said to be antelopes, have been discovered. They are classed by Gervais in the genera Antilope and Leptotherivm, but the presence of true antelopes in S. America at this period is so improbable, that there is probably some error of identification.
The extinct family Sivatheridse, containing the extraordinary and gigantic four-horned Sivatlwrium and Bramatherium, of the Siwalik deposits, are most nearly allied to the antelopes.
From the preceding facts we may conclude, that the great existing development of the Bovidae is comparatively recent. The type may have originated early in the Miocene period, the oxen being at first most tropical, while the antelopes inhabited the desert zone a little further north. The sheep and goats seem to be the most recent development of the bovine type, which was probably long confined to the Eastern Hemisphere.
General Remarks on the Distribution of the Ungvlata.
With the exception of the Australian region, from which this order of mammalia is almost entirely wanting, the Ungulata are almost universally distributed over the continental parts of all the other regions. Of the ten families, 7 are Ethiopian, 6 Oriental, 5 Pahearctic, 4 Neotropical, and 3 Nearctic. The Ethiopian region owes its superiority to the exclusive possession of the hippopotamus and giraffe, both of which inhabited the Pahearctic and Oriental regions in Miocene times. The excessive poverty of the Nearctic region in this order is remarkable; the swine being represented only by Dicotyles in its extreme southern portion, while the Bovidae are restricted to four isolated species. Deer alone are fairly well represented. But, during the Eocene and Miocene periods, North America was wonderfully rich in varied forms of Ungulates, of which there were at least 8 or 9 families; while we have reason to believe that during the same periods the Ethiopian region was excessively poor, and that it probably received the ancestors of all its existing families from Europe or Western Asia in later Miocene or Pliocene times. Many types that onqe abounded in both Europe and North America are now preserved only in South America and Central or Tropical Asia,—as the tapirs and camels; while others once confined to Europe and Asia have found a refuge in Africa,—as the hippopotamus and giraffe; so that in no other order do we find such striking examples of those radical changes in the distribution of the higher animals which were effected during the latter part of the Tertiary period. The present distribution of this order is, in fact, utterly unintelligible without reference to the numerous extinct forms of existing and allied families; but as this subject has been sufficiently discussed in the Second Part of this work (Chapters VI. and VII.) it is unnecessary to give further details here.
The elephants are now represented by two species, the African, which ranges all over that continent south of the Sahara, and the Indian, which is found over all the wooded parts of the Oriental region, from the slopes of the Himalayas to Ceylon, and eastward, to the frontiers of China and to Sumatra and Borneo. These, however, are but the feeble remnants of a host of gigantic creatures, which roamed over all the great continents except Australia during the Tertiary period, and several of which were contemporary with man.
Extinct Elephants.—At least 14 extinct species of Elephas, and a rather greater number of the allied genus Mastodon (distinguished by their less complex grinding teeth) have now been discovered. Elephants ranged over all the Palsearctic and Nearctic regions in Post-Pliocene times; in Europe and Central India they go back to the Pliocene; and only in India to the Upper Miocene period; the number of species increasing as we go back to the older formations.
In North America two or three species of Mastodon are Postpliocene and Pliocene ; and a species is found in the caves of Brazil, and in the Pliocene deposits of the pampas of La Plata, of the Bolivian Andes, and of Honduras and the Bahamas. In Europe the genus is Upper Miocene and Pliocene, but is especially abundant in the former period. In the East, it extends from Perim island to Burmah and over all India, and is mostly Miocene, but with perhaps one species Pliocene in Central India.
An account of the range of such animals as belong to extinct families of Proboscidea, will be found in Chapters VI. and VIT.; from which it will be seen that, although the family Elephantidae undoubtedly originated in the Eastern Hemisphere, it is not improbable that the first traces of the order Proboscidea are to be found in N. America.
Family 54.-HYBACID.E. (1 Genus. 10-12 Species.)
The genus Hyrax, which alone constitutes this family, consists of small animals having the appearance of hares or marmots, but which more resemble the genus Rhinoceros in their teeth and skeleton. They range all over the Ethiopian region, except Madagascar; a peculiar species is found in Fernando Po, and they just enter the Palsearctic as far as Syria. They may therefore be considered as an exclusively Ethiopian group. In Dr. Gray's last Catalogue (1873) he divides the genus into three—Hyrax, Euhyrax and Dendrohyrax—the latter consisting of two species confined apparently to West and South Africa.
No extinct forms of this family have yet been discovered; the Hyracolherium of the London clay (Lower Eocene) which was supposed to resemble Hyrax, is now believed to be an ancestral type of the Suidse or swine.
The Muridse, comprising the rats and mice with their allies, are almost universally distributed over the globe (even not reckoning the domestic species which have been introduced almost everywhere by man), the exceptions being the three insular groups belonging to the Australian region, from none of which have any species yet been obtained. Before enumerating the genera it will be as well to say a few words on the peculiarities of distribution they present. The true mice, forming the genus Mus, is distributed over the whole of the world except N. and S. America where not a single indigenous species occurs, being replaced by the genus Hesperomys; five other genera, comprehending all the remaining species found in South America are peculiar to the Neotropical region. Three genera are confined to the Palsearctic region, and three others to the Nearctic. No less than twelve genera are exclusively Ethiopian, while only three are exclusively Oriental and three Australian.
Mus (100-120 sp.) the Eastern Hemisphere, but absent from the Pacific and Austro-Malayan Islands, except Celebes and Papua; Latiomys (1 sp.) Guinea; Acanthomys (5-6 sp.) Africa, India and