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Which mammals occur west of Wallace’s Line in Southeast Asian rainforests?

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World map using color coding to show the distribution of major floral kingdoms, subkingdoms, and regions. Key floral kingdoms include Boreal (green), Neotropical (pink), Paleotropical (yellow), South African or Capensic (purple), Australian (orange), and Antarctic (blue). Boundaries for subkingdoms, regions, and divisions are marked with different colored lines, and major regions such as Indoafrican, North American, and Malesian are labeled across continents. — biogeographic region Floral kingdoms, subkingdoms, and major regions of the world.

West of Wallace’s Line, the tropical rainforests of Southeast Asia are characterized by a diverse population of placental mammals. This region, which includes areas such as the Greater Sunda Islands, serves as a boundary where the Oriental faunal region is distinct from the Australian region to the east.123

Mammals commonly found in these western rainforests include:

Primates: Various species of monkeys, gibbons, and orangutans.
Ungulates: Deer, pigs, and rhinoceroses.
Large Mammals: Elephants and cats (such as tigers).12
Other Mammals: Civets, mongooses, and tapirs.42

While some groups like bats and rodents are common on both sides of the line, the presence of these placental mammals to the west contrasts sharply with the marsupial mammals (such as cuscuses and tree kangaroos) that dominate the rainforests to the east.1