If it is a Strepsirrhine, it is not a monkey. If it is a monkey, it is not a Strepsirrhine.

A strepsirrhine is a primate belonging to the order (group) Strepsirrhini, one of the two primate orders. Examples of strepsirrhines include lemurs, aye-ayes, and lorises. Monkeys and apes are NOT strepsirrhines.

Lemurs, tarsiers, and lorises belong to a group of primates called prosimians.

The sub-order Strepsirrhini (curly-nosed primates) are non-tarsier prosimians, and the sub-order Haplorrhini (dry-nosed primates) includes tarsiers and simians.

The Primates order has traditionally been divided into two main groupings: prosimians and simians. Prosimians have characteristics most like those of the earliest primates, and included the lemurs of Madagascar, lorisiforms and tarsiers. Simians included the monkeys and apes. More recently, taxonomists have created the suborder Strepsirrhini, or curly-nosed primates.

No, lemurs are strepsirrhines, a completely different branch of primates.

We are humans (Homo sapiens), a member of the taxonomic order primates. In the order primates there are two main sub-orders: strepsirrhini (lemurs, lorises and bush-babies) and haplorhini (tarsiers, monkeys, apes and humans). We are all members of the same order based on certain synapomorphies (i.e., shared, derived traits) that distinguish us from other mammals, which is referred to as the 'primate pattern'. Some of these traits include: forward-facing eyes with stereoscopic vision, grasping hands and feet with opposable halluces and nails instead of claws, larger encephalization than other mammals, a long period of infant dependency and a tendency to give birth to singletons instead of litters, and so forth. As humans, we belonging to the suborder haplorhini. We certainly aren't monkeys as the last poster noted, nor did we 'evolve' from monkeys. Rather, share a last common ancestor with these other priamtes in our distant evolutionary past. The living apes (i.e., Hylobates, Pongo, Gorilla and Pan) shared a LCA with the lineage leading to our own genus at ~ 14, 7, 4 and 2 Mya, respectively.

35 million years ago. Old World monkeys and Hominoidea emerged within the catarrhine monkeys some 25 million years ago. Extinct basal simians such as Aegyptopithecus or Parapithecus [35-32 million years ago], eosimiidea and sometimes even the Catarrhini group are also considered monkeys by primatologists.Lemurs, lorises, and galagos are not monkeys; instead they are strepsirrhine primates. Like monkeys, tarsiers are haplorhine primates; however, they are also not monkeys. Apes emerged within "monkeys" as sister of the Cercopithecidae in the Catarrhini, so cladistically they are monkeys as well. There has been resistance to directly designate apes (and thus humans) as monkeys, so "Old World monkey" may be taken to mean the Cercopithecoidea or the Catarrhini. That apes are monkeys was already realized by Georges-Louis Leclerc, Comte de Buffon in the 18th century.Monkeys, including apes, can be distinguished from other primates by having only two pectoral nipples, a pendulous penis, and a lack of sensory whiskers. According to the Online Etymology Dictionary, the word "monkey" may originate in a German version of the Reynard the Fox fable, published circa 1580. In this version of the fable, a character named Moneke is the son of Martin the Ape. In English, no very clear distinction was originally made between "ape" and "monkey"; thus the 1911 Encyclopædia Britannica entry for "ape" notes that it is either a synonym for "monkey" or is used to mean a tailless humanlike primate. Colloquially, the terms "monkey" and "ape" are widely used interchangeably. Also, a few monkey species have the word "ape" in their common name, such as the Barbary ape. Later in the first half of the 20th century, the idea developed that there were trends in primate evolution and that the living members of the order could be arranged in a series, leading through "monkeys" and "apes" to humans. Monkeys thus constituted a "grade" on the path to humans and were distinguished from "apes". Scientific classifications are now more often based on monophyletic groups, that is groups consisting of all the descendants of a common ancestor. The New World monkeys and the Old World monkeys are each monophyletic groups, but their combination was not, since it excluded hominoids (apes and humans). Thus the term "monkey" no longer referred to a recognized scientific taxon. The smallest accepted taxon which contains all the monkeys is the infraorder Simiiformes, or simians. However this also contains the hominoids, so that monkeys are, in terms of currently recognized taxa, non-hominoid simians. Colloquially and pop-culturally, the term is ambiguous and sometimes monkey includes non-human hominoids. In addition, frequent arguments are made for a monophyletic usage of the word "monkey" from the perspective that usage should reflect cladistics.A group of monkeys may be commonly referred to as a tribe or a troop.Two separate groups of primates are referred to as "monkeys": New World monkeys (platyrrhines) from South and Central America and Old World monkeys (catarrhines in the superfamily Cercopithecoidea) from Africa and Asia. Apes (hominoids)—consisting of gibbons, orangutans, gorillas, chimpanzees, and humans—are also catarrhines but were classically distinguished from monkeys. (Tailless monkeys may be called "apes", incorrectly according to modern usage; thus the tailless Barbary macaque is sometimes called the "Barbary ape".) As apes have emerged in the monkey group as sister of the old world monkeys, characteristics that describe monkeys are generally shared by apes as well. Williams et al outlined evolutionary features, including in stem groupings, contrasted against the other primates such as the tarsiers and the lemuriformes.Monkeys range in size from the pygmy marmoset, which can be as small as 117 millimetres (4.6 in) with a 172-millimetre (6.8 in) tail and just over 100 grams (3.5 oz) in weight, to the male mandrill, almost 1 metre (3.3 ft) long and weighing up to 36 kilograms (79 lb). Some are arboreal (living in trees) while others live on the savanna; diets differ among the various species but may contain any of the following: fruit, leaves, seeds, nuts, flowers, eggs and small animals (including insects and spiders).Some characteristics are shared among the groups; most New World monkeys have prehensile tails while Old World monkeys have non-prehensile tails or no visible tail at all. Old World monkeys have trichromatic color vision like that of humans, while New World monkeys may be trichromatic, dichromatic, or—as in the owl monkeys and greater galagos—monochromatic. Although both the New and Old World monkeys, like the apes, have forward-facing eyes, the faces of Old World and New World monkeys look very different, though again, each group shares some features such as the types of noses, cheeks and rumps. The following list shows where the various monkey families (bolded) are placed in the classification of living (extant) primates. ORDER PRIMATES Suborder Strepsirrhini: lemurs, lorises, and galagos Suborder Haplorhini: tarsiers, monkeys, and apes Infraorder Tarsiiformes Family Tarsiidae: tarsiers Infraorder Simiiformes: simians Parvorder Platyrrhini: New World monkeys Family Callitrichidae: marmosets and tamarins (42 species) Family Cebidae: capuchins and squirrel monkeys (14 species) Family Aotidae: night monkeys (11 species) Family Pitheciidae: titis, sakis, and uakaris (41 species) Family Atelidae: howler, spider, and woolly monkeys (24 species) Parvorder Catarrhini Superfamily Cercopithecoidea Family Cercopithecidae: Old World monkeys (135 species) Superfamily Hominoidea: apes Family Hylobatidae: gibbons ("lesser apes") (17 species) Family Hominidae: great apes (including humans, gorillas, chimpanzees, and orangutans) (8 species) Below is a cladogram with some extinct monkey families. Generally, extinct non-hominoid simians, including early Catarrhines are discussed as monkeys as well as simians or anthropoids, which cladistically means that Hominoidea are monkeys as well, restoring monkeys as a single grouping. It is indicated approximately how many million years ago