Tarsiiformes in the context of "Simian"

Primates is an order of mammals, which is further divided into the strepsirrhines, which include lemurs, galagos, and lorisids; and the haplorhines, which include tarsiers and simians (monkeys and apes). Primates arose 74–63 million years ago first from small terrestrial mammals, which adapted for life in tropical forests: many primate characteristics represent adaptations to the challenging environment among tree tops, including large brain sizes, binocular vision, color vision, vocalizations, shoulder girdles allowing a large degree of movement in the upper limbs, and opposable thumbs (in most but not all) that enable better grasping and dexterity. Primates range in size from Madame Berthe's mouse lemur, which weighs 30 g (1 oz), to the eastern gorilla, weighing over 200 kg (440 lb). There are 376–524 species of living primates, depending on which classification is used. New primate species continue to be discovered: over 25 species were described in the 2000s, 36 in the 2010s, and six in the 2020s.

Primates have large brains (relative to body size) compared to other mammals, as well as an increased reliance on visual acuity at the expense of the sense of smell, which is the dominant sensory system in most mammals. These features are more developed in monkeys and apes, and noticeably less so in lorises and lemurs. Some primates, including gorillas, humans and baboons, are primarily ground-dwelling rather than arboreal, but all species have adaptations for climbing trees. Arboreal locomotion techniques used include leaping from tree to tree and swinging between branches of trees (brachiation); terrestrial locomotion techniques include walking on two hindlimbs (bipedalism) and modified walking on four limbs (quadrupedalism) via knuckle-walking.

Haplorhini (/hæpləˈraɪnaɪ/), the haplorhines (Greek for "simple-nosed") or the "dry-nosed" primates is a suborder of primates containing the tarsiers and the simians (Simiiformes or anthropoids), as sister of the Strepsirrhini ("moist-nosed"). The name is sometimes spelled Haplorrhini. The simians include catarrhines (Old World monkeys and apes, including humans), and the platyrrhines (New World monkeys).

Haplorhini was proposed by Pocock in 1918 when he realized the tarsiers were actually sister to the monkeys rather than the lemurs, also following findings of Hugh Cuming 80 years earlier and Linnaeus 160 years earlier. For Linnaeus, this ensemble of primates constituted a genus "Simia". For religious reasons, Homo constituted its own genus (which has remained).

Tarsiers (/ˈtɑːrsiərz/ TAR-see-ərz) are haplorhine primates of the family Tarsiidae, which is the lone extant family within the infraorder Tarsiiformes. Although the group was prehistorically more globally widespread, all of the existing species are restricted to Maritime Southeast Asia, predominantly in Brunei, Indonesia, Malaysia and the Philippines.

They are found primarily in forested habitats, especially forests that have liana, since the vine gives tarsiers vertical support when climbing trees.

Afrotarsius is a primate found in the Paleogene of Africa.

The first species to be named, Afrotarsius chatrathi, was named in 1985 on the basis of a single lower jaw from the Oligocene of Fayum, Egypt, and tentatively referred to the tarsier family (Tarsiidae). However, this relationship immediately proved controversial, and in 1987 the animal was placed in a separate family Afrotarsiidae related to simians. A tarsier-like tibiofibula was allocated to Afrotarsius in 1998, but the identity of this bone is controversial. In 2010, a second species of the genus, Afrotarsius libycus, was named from the Eocene of Dur At-Talah, Libya, on the basis of isolated upper and lower teeth. Features of these teeth were interpreted as additional evidence for a relationship between Afrotarsius and anthropoids. A second afrotarsiid genus, Afrasia, was named in 2012 from the Eocene Pondaung Formation of Myanmar. In the same paper, Afrotarsiidae was placed together with the Asian Eosimiidae in an infraorder Eosimiiformes, in the simians. However, some studies indicate that it should be placed in Tarsiiformes.

Omomyidae is a group of early primates that radiated during the Eocene epoch between about 55 to 34 million years ago (mya). Fossil omomyids are found in North America, Europe & Asia, making it one of two groups of Eocene primates with a geographic distribution spanning holarctic continents, the other being the adapids (family Adapidae). Early representatives of the Omomyidae and Adapidae appear suddenly at the beginning of the Eocene (56 mya) in North America, Europe, and Asia, and are the earliest known crown primates.

Omomyids are generally as regarded as closely related to or within the Tarsiiformes, and thus most closely related to tarsiers among living primates.