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MADAGASCAR
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MADAGASCAR and certain other islands have a See also:fauna which is as remarkable for its deficiencies as it is for its See also:present forms. The following well-defined See also:groups are absent: Trionychidae and Chelydidae; Agamidae, Lacertidae, Anguidae, Amphisbaenidae, Varanidae and Eublepharinae; all the Viperidae and Elapinae, so that this large See also:island enjoys perfect See also:absence of poisonous See also:snakes, not counting the practically harmless opisthoglyphous See also:tree snakes; there are further no pythons and no ilysias. The actual fauna consists of: Crocodilus vulgaris, which is said to be extremely abundant; of Chelonians, Pelomedusa galeata and ' The same authority enumerates 536 See also:species of See also:reptiles for See also:British See also:India, i.e. about one-See also:sixth of all the See also:recent species of reptiles (Fauna of British India, edit. W. T. See also:Blanford, See also:London, 1890). Sternothaerus, both also in See also:Africa, Podocnemis, which elsewhere occurs in See also:South See also:America only, and several Testudinidae; of these Pyxis is See also:peculiar to Madagascar, while Testudo has furnished the gigantic tortoises of See also:Aldabra, the See also:Seychelles, and recently See also:extinct in See also:Mauritius and Madagascar. Of lizards are present a few Gerrhosauridae and Zonuridae, both See also:African types; the remarkable occurrence of two iguanid genera Chalarodon and Hoplurus, both peculiar to the island; skinks, many geckos, and Uroplates, See also:sole type of the Uroplatinae and an abundance of chameleons, of the genera See also:Chameleon, with Ch. See also:parson, the See also:giant of the See also:family, and the small species of Brookesia, a genus peculiar to Madagascar. Of snakes we See also:note Typhlopidae and Glauconiidae, and the remarkable occurrence of Boinae, two of the genus See also:Boa (Pelophilus), one of Corallus on the See also:main island and Casarea on See also:Round Island. There are opisthoglyphous mostly arboreal snakes, and the See also:rest are innocuous colubrines, some few with See also:Indian and African See also:affinities, e.g. Zamenis s. Ptyas, more with apparently S. See also:American relation-See also:ship, or at least with resemblance in taxonomic characters. An See also:analysis of this peculiarly See also:compound and deficient fauna gives surprising results, namely, the almost See also:total absence of See also:affinity with the Indian region, See also:close connexion with Africa by the See also:possession of Gerrhosauridae, Zonuridae, Chameleons and Pelomedusidae; lastly, the presence of several tree boas, of Podocnemis and of Iguanidae, i.e. families and genera which we are accustomed to consider as typically neo-tropical. Peculiar to Madagascar, autochthonous and very See also:ancient, is only Uroplates. Ancient are also the tortoises, chameleons, geckos, boas, typhlops, gerrhosaurids and zonurids. The absent families may be as ancient as the others, but most of them, notably Varanus, lacertids and agamids are of distinctly See also:northern, palaeotropical origin, and we can conclude with certainty that they had not spread into S. Africa before Madagascar and its satellites became severed from the See also:continent. Additional information and CommentsThere are no comments yet for this article.
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