:''This article is about the Indomalayan geographical region. For the ethnic Albanian highland region in Montenegro and Albania, see
Malësia. For other uses, see
Malesia (disambiguation).
'Malesia' is a
biogeographical region straddling the boundary of the
Indomalaya and
Australasia ecozones. Malesia was first identified as a
floristic province that included the
Malay Peninsula,
Indonesia, the
Philippines and
New Guinea, based on a shared tropical flora derived mostly from
Asia but also with numerous elements of the
Antarctic flora, including many species in the southern
conifer families
Podocarpaceae and
Araucariaceae. The floristic province overlaps four distinct
mammalian faunal regions.
The western part of Malesia, which includes the Malay Peninsula and the islands of
Sumatra,
Java,
Bali, and
Borneo, shares the large mammal fauna of Asia, and is known as
Sundaland. These islands are on Asia's relatively shallow continental shelf, and were linked to Asia during the
ice ages, when sea levels were lower. The eastern edge of Sundaland is the
Wallace line, named for
Alfred Russel Wallace, the nineteenth-century British naturalist who noted the difference in fauna between islands on either side of the line.
The eastern end of Malesia, which includes New Guinea and the
Aru Islands of eastern Indonesia, is linked to Australia by a shallow continental shelf, and shares many
marsupial mammal and bird
taxa with Australia. New Guinea also has many additional elements of the Antarctic flora, including southern beech (''
Nothofagus'') and gums (''
Eucalyptus'').
The islands between Sundaland and New Guinea, called
Wallacea, were never linked to the neighboring continents, and have a flora and fauna that includes Indomalayan and Australasian elements. The
Philippines were also never connected to Asia, and have a largely Asian-derived flora, with some Australasian elements, and a distinct mammalian fauna.