The Sarawak surili, Bornean banded langur, or cross-marked langur (''Presbytis chrysomelas'') is a species of
primate
Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...
in the family
Cercopithecidae
Old World monkeys are primates in the family (biology), family Cercopithecidae (). Twenty-four genus, genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons (genus ''Papio''), red colo ...
. It is
endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to the
southeast Asia
Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...
n island of
Borneo
Borneo () is the List of islands by area, third-largest island in the world, with an area of , and population of 23,053,723 (2020 national censuses). Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda ...
, where it is distributed north of the
Kapuas River
The Kapuas River ( Old Indonesian spelling: Kapoeas River) is a river in the Indonesian part of Borneo island, at the geographic center of Maritime Southeast Asia. At in length, it is the longest river on the island of Borneo, the longest ri ...
in
Kalimantan
Kalimantan (; ) is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area, and consists of the provinces of Central Kalimantan, East Kalimantan, North Kalimantan, South Kalimantan, and West Kalimantan. The non-Ind ...
,
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...
, the
Malaysia
Malaysia is a country in Southeast Asia. Featuring the Tanjung Piai, southernmost point of continental Eurasia, it is a federation, federal constitutional monarchy consisting of States and federal territories of Malaysia, 13 states and thre ...
states of
Sarawak
Sarawak ( , ) is a States and federal territories of Malaysia, state of Malaysia. It is the largest among the 13 states, with an area almost equal to that of Peninsular Malaysia. Sarawak is located in East Malaysia in northwest Borneo, and is ...
and
Sabah
Sabah () is a States and federal territories of Malaysia, state of Malaysia located in northern Borneo, in the region of East Malaysia. Sabah has land borders with the Malaysian state of Sarawak to the southwest and Indonesia's North Kalima ...
, and in
Brunei
Brunei, officially Brunei Darussalam, is a country in Southeast Asia, situated on the northern coast of the island of Borneo. Apart from its coastline on the South China Sea, it is completely surrounded by the Malaysian state of Sarawak, with ...
. Its
taxonomy
image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy
Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...
is complex and disputed, and it has been considered a
subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
of '' P. femoralis'' or '' P. melalophos''. The Sarawak surili was formerly considered common, but has declined drastically due to persecution and
habitat loss
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
, and as of 2015 is only known from five sites with a combined population of 200–500 individuals. Consequently, it is believed to be one of the rarest primates in the world, and has been rated as
critically endangered
An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...
by
IUCN
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...