The Indomalayan realm is one of the eight biogeographic realms . It extends across most of South and Southeast Asia and into the southern parts of East Asia .
16-645: See text Isma is an Indomalayan genus of grass skippers in the family Hesperiidae . Listed alphabetically: The larvae feed on Musa , Pandanus . This Hesperiinae -related article is a stub . You can help Misplaced Pages by expanding it . Indomalayan realm Also called the Oriental realm by biogeographers , Indomalaya spreads all over the Indian subcontinent and Southeast Asia to lowland southern China , and through Indonesia as far as Sumatra , Java , Bali , and Borneo , east of which lies
32-590: Is characteristic of the seasonally dry forests of the Indomalaya, from India through Indochina, Malaysia, and the Philippines. Tropical pitcher plants ( Nepenthes ) are also characteristic of Indomalaya, and the greatest diversity of species is in Sumatra, Borneo, and the Philippines. The tropical forests of Indomalaya and Australasia share many lineages of plants, which have managed over millions of years to disperse across
48-588: Is implied, so that any such year number "X Ma" between 66 and 145 is "Cretaceous", for good reason. But the counter argument is that having myr for a duration and Mya for an age mixes unit systems, and tempts capitalization errors: "million" need not be capitalized, but "mega" must be; "ma" would technically imply a milliyear (a thousandth of a year, or 8 hours). On this side of the debate, one avoids myr and simply adds ago explicitly (or adds BP ), as in: The Cretaceous started 145 Ma ago and ended 66 Ma ago, lasting for 79 Ma. In this case, "79 Ma" means only
64-421: Is in common use in fields such as Earth science and cosmology . Myr is also used with Mya or Ma. Together they make a reference system, one to a quantity, the other to a particular point in a year numbering system that is time before the present . Myr is deprecated in geology , but in astronomy Myr is standard. Where "myr" is seen in geology, it is usually "Myr" (a unit of mega-years). In astronomy, it
80-448: Is usually "Myr" (Million years). In geology, a debate remains open concerning the use of Myr (duration) plus Ma (million years ago) versus using only the term Ma . In either case, the term Ma is used in geology literature conforming to ISO 31-1 (now ISO 80000-3 ) and NIST 811 recommended practices. Traditional style geology literature is written: The Cretaceous started 145 Ma and ended 66 Ma, lasting for 79 Myr. The "ago"
96-668: The Wallace line , the realm boundary named after Alfred Russel Wallace which separates Indomalaya from Australasia . Indomalaya also includes the Philippines , lowland Taiwan , and Japan 's Ryukyu Islands . Most of Indomalaya was originally covered by forest, and includes tropical and subtropical moist broadleaf forests , with tropical and subtropical dry broadleaf forests predominant in much of India and parts of Southeast Asia. The tropical forests of Indomalaya are highly variable and diverse, with economically important trees, especially in
112-478: The colugos (Dermoptera) and treeshrews (Scandentia), are endemic to the realm, as are families Craseonycteridae ( Kitti's hog-nosed bat ), Diatomyidae , Platacanthomyidae , Tarsiidae ( tarsiers ) and Hylobatidae ( gibbons ). Large mammals characteristic of Indomalaya include the leopard , tigers , water buffalos , Asian elephant , Indian rhinoceros , Javan rhinoceros , Malayan tapir , orangutans , and gibbons . Indomalaya has three endemic bird families,
128-580: The Irenidae ( fairy bluebirds ), Megalaimidae and Rhabdornithidae ( Philippine creepers ). Also characteristic are pheasants , pittas , Old World babblers , and flowerpeckers . Indomalaya has 1000 species of amphibians in 81 genera, about 17 of global species. 800 Indomalayan species, or 80%, are endemic. Indomalaya has three endemic families of amphibians, Nasikabatrachidae , Ichthyophiidae , and Uraeotyphlidae . 329, or 33%, of Indomalayan amphibians are considered threatened or extinct, with habitat loss as
144-582: The bioregion on the northwest, north, and northeast; these ranges were formed by the collision of the northward-drifting Indian subcontinent with Asia beginning 45 million years ago. The Hindu Kush, Karakoram, and Himalaya are a major biogeographic boundary between the subtropical and tropical flora and fauna of the Indian subcontinent and the temperate-climate Palearctic realm. The Indochina bioregion includes most of mainland Southeast Asia , including Myanmar , Thailand , Laos , Vietnam , and Cambodia , as well as
160-437: The dipterocarps, island-hopped across Wallacea to New Guinea, and several Gondwanian plant families, including podocarps and araucarias , moved westward from Australia-New Guinea into western Malesia and Southeast Asia. The subfamily Dipterocarpoideae comprises characteristic tree species in Indomalaya's moist and seasonally dry forests, with the greatest species diversity in the moist forests of Borneo . Teak ( Tectona )
176-560: The families Dipterocarpaceae and Fabaceae . The World Wildlife Fund (WWF) divides Indomalayan realm into three bio-regions, which it defines as "geographic clusters of eco-regions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)". The Indian subcontinent bioregion covers most of India , Bangladesh , Nepal , Bhutan , and Sri Lanka and eastern parts of Pakistan . The Hindu Kush , Karakoram , Himalaya , and Patkai ranges bound
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#1732838077218192-499: The islands east of the Wallace line are derived at least in part from species of Australian origin, such as marsupial mammals and ratite birds. The flora of Indomalaya blends elements from the ancient supercontinents of Laurasia and Gondwana . Gondwanian elements were first introduced by India, which detached from Gondwana approximately 90 MYA , carrying its Gondwana-derived flora and fauna northward, which included cichlid fish and
208-472: The plant families Crypteroniaceae and possibly Dipterocarpaceae . India collided with Asia 30-45 MYA, and exchanged species. Later, as Australia-New Guinea drifted north, the collision of the Australian and Asian plates pushed up the islands of Wallacea , which were separated from one another by narrow straits, allowing a botanic exchange between Indomalaya and Australasia . Asian rainforest flora, including
224-404: The principal cause. More information is available under Indomalayan realm fauna . 7°00′N 97°00′E / 7.000°N 97.000°E / 7.000; 97.000 Mya (unit) Million years ago , abbreviated as Mya , Myr (megayear) or Ma (megaannum), is a unit of time equal to 1,000,000 years (i.e. 1 × 10 years), or approximately 31.6 teraseconds . Myr
240-491: The straits and islands between Sundaland and New Guinea. The two floras evolved in long isolation, and the fossil record suggests that Asian species dispersed to Australasia starting 33 million years ago as Australasia moved northwards, and dispersal increased 12 million years ago as the two continents approached their present positions. The exchange was asymmetric, with more Indomalayan species spreading to Australasia than Australasian species to Indomalaya. Two orders of mammals,
256-676: The subtropical forests of southern China . Malesia is a botanical province which straddles the boundary between Indomalaya and Australasia. It includes the Malay Peninsula and the western Indonesian islands (known as Sundaland ), the Philippines, the eastern Indonesian islands, and New Guinea. While the Malesia has much in common botanically, the portions east and west of the Wallace Line differ greatly in land animal species; Sundaland shares its fauna with mainland Asia, while terrestrial fauna on
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