Palaeontology tells us nothing with regard to the origin of the Chiroptera, all the known fossil species, some of which date back to the Oligocene, being more or less closely allied to existing types, and therefore of comparatively little interest. The origin of the order from primitive insectivorous mammals must have taken place at least as early as the Lower Eocene. It is, however, noteworthy that several of the earlier extinct species appear to be related to the Rhinolophidae, which is the most generalized family of the order. Remains of Pteropodidae belonging to existing genera occur in the caves of tropical countries in the eastern hemisphere; and the skeleton of an extinct generic type, Archaeopteropus, has been obtained from the Miocene lignite of Italy, which indicates a form to a certain extent transitional in character between typical fruit-bats and the insectivorous bats. The tail, for instance, which in most modern fruit-bats is rudimentary, with only three or four vertebrae, in the fossil has eight complete vertebrae; while the teeth of the extinct form are distinctly cusped. Whether, however, the tail is longer than in the existing Notopteris of Fiji and New Guinea, or whether the molars are more distinctly cusped than is the case with the Solomon Island Pteropus (Pteralopex), is not stated. Still, the fact that the Miocene fruit-bat does show certain signs of approximation to the insectivorous (and more generalized) section of the order is of interest. Of the Oligocene forms, Pseudorhinolophus of Europe is apparently a member of the Rhinolophidae; but the affinities of Alastor and Vespertiliavus, which are likewise European, are more doubtful, although the latter may be related to Taphozous. The North American Vespertilio (Vesperugo) anemophilus and the European V. aquensis and V. parisiensis are, on the other hand, members of the Vespertilionidae, the last being apparently allied to the serotine (V. serotinus).
AUTHORITIES.—The above article is based to some extent on the article in the 9th edition of this work by G.E. Dobson, whose British Museum “Catalogue” is, however, now obsolete. Professor H. Winge’s “Jordfundae og nulevende Flagermus (Chiroptera),” published in E. Mus. Lundi (Copenhagen, 1892), contains much valuable information; and for Pteropodidae Dr P. Matschie’s Megachiroptera (Berlin, 1899), should be consulted. For the rest the student must refer to namerous papers by G.M. Allen, K. Andersen, F.A. Jentink, G.S. Miller, T.S. Palmer, A.G. Rehn, O. Thomas and others, in various English and American zoological serials, all of which are quoted in the volumes of the Zoological Record.
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[1] Bull. Amer. Mus. Nat. Hist. vol. xii. (1899).
[2] Proc. Zool. Soc. (London, 1904), vol. ii.
CHIRU, a graceful Tibetan antelope (Pantholops Hodgsoni), of which the bucks are armed with long, slender and heavily-ridged horns of an altogether peculiar type, while the does are hornless. Possibly this handsome antelope may be the original of the mythical unicorn, a single buck when seen in profile looking exactly as if it had but one long straight horn. Although far from uncommon, chiru are very wary, and consequently difficult to approach. They are generally found in small parties, although occasionally in herds. They inhabit the desolate plateau of Tibet, at elevations of between 13,000 and 18,000 ft., and, like all Tibetan animals, have a firm thick coat, formed in this instance of close woolly hair of a grey fawn-colour. The most peculiar feature about the chiru is, however, its swollen, puffy nose, which is probably connected with breathing a highly rarefied atmosphere. A second antelope inhabiting the same country as the chiru is the goa (Gazella picticaudata), a member of the gazelle group characterized by the peculiar form of the horns of the bucks and certain features of coloration, whereby it is markedly distinguished from all its kindred save one or two other central Asian species. The chiru, which belongs to the typical or antilopine section of antelopes, is probably allied to the saiga.
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