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42-536: See text Spider monkeys are New World monkeys belonging to the genus Ateles , part of the subfamily Atelinae , family Atelidae . Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil . The genus consists of seven species, all of which are under threat; the brown spider monkey is critically endangered. They are also notable for their ability to be easily bred in captivity. Disproportionately long limbs and long prehensile tails make them one of

84-443: A clitoris that is especially developed; it may be referred to as a pseudo-penis because it has an interior passage, or urethra, that makes it almost identical to the penis , and retains and distributes urine droplets as the female moves around. This urine is emptied at the bases of the clitoris, and collects in skin folds on either side of a groove on the perineal. Researchers and observers of spider monkeys of South America look for

126-427: A dental formula of 2.1.3.3 2.1.3.3 or 2.1.3.2 2.1.3.2 (consisting of 2 incisors, 1 canine, 3 premolars, and 2 or 3 molars). This is in contrast with Old World Anthropoids, including gorillas , chimpanzees , bonobos , siamangs , gibbons , orangutans , and most humans , which share a dental formula of 2.1.2.3 2.1.2.3 . Many New World monkeys are small and almost all are arboreal , so knowledge of them

168-444: A 395-million-year-old fossilized fish which shows this migration in progress. It has two nostrils between its front teeth, similar to human embryos at an early stage. If these fail to join up, the result is a cleft palate . Each external nostril contains approximately 1,000 strands of nasal hair , which function to filter foreign particles such as pollen and dust. It is possible for humans to smell different olfactory inputs in

210-482: A flat structure. One possible arrangement of the five families and their subfamilies of Rylands & Mittermeier can be seen in Silvestro et al. (2017): titis sakis and uakaris howler monkeys spider, woolly spider, and woolly monkeys capuchins squirrel monkeys marmosets and lion tamarins tamarins and saddle-back tamarins night monkeys New World monkeys are small to mid-sized primates, ranging from

252-708: A line that split off about 40 million years ago. About 40 million years ago, the Simiiformes infraorder split into the parvorders Platyrrhini (New World monkeys) and Catarrhini (apes and Old World monkeys ) somewhere on the African continent. Platyrrhini are currently conjectured to have dispersed to South America on a raft of vegetation across the Atlantic Ocean during the Eocene epoch, possibly via several intermediate now submerged islands. Several other groups of animals made

294-452: A scrotum to determine the animal sex because these female spider monkeys have pendulous and erectile clitorises long enough to be mistaken for a penis; researchers may also determine the animal's sex by identifying scent-marking glands that may be present on the clitoris. Spider monkeys form loose groups, typically with 15 to 25 individuals, but sometimes up to 30 or 40. During the day, groups break up into subgroups. The size of subgroups and

336-563: A single gene on the X-chromosome to produce pigments that absorb medium and long wavelength light, which contrasts with short wavelength light. As a result, males rely on a single medium/long pigment gene and are dichromatic , as are homozygous females. Heterozygous females may possess two alleles with different sensitivities within this range, and so can display trichromatic vision. Platyrrhines also differ from Old World monkeys in that they have twelve premolars instead of eight; having

378-508: A wide variety (over 150 species) of plants. This requires the monkeys to remember when and where fruit can be found. The slow development may also play a role: the monkeys may live from 20 to 27 years or more, and females give birth once every 17 to 45 months. Gummy, presumably the oldest spider monkey in captivity, is presumed to have been born wild in 1962 and currently resided at Fort Rickey Childrens Discovery Zoo located in Rome, New York, and died at

420-472: Is closely associated with its territory. If the group is big, it spreads out. The female chooses a male from her group for mating. Both males and females use "anogenital sniffing" to check their mates for readiness for copulation. The gestation period ranges from 226 to 232 days. Each female bears only one offspring on average, every three to four years. Until six to ten months of age, infants rely completely on their mothers. Males are not involved in raising

462-460: Is coarse, ranging in color from ruddy gold to brown and black, or white in a rare number of specimens. The hands and feet are usually black. Heads are small with hairless faces. The nostrils are very far apart, which is a distinguishing feature of spider monkeys. Spider monkeys are highly agile, and they are said to be second only to the gibbons in this respect. They have been seen in the wild jumping from tree to tree. Female spider monkeys have

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504-559: Is derived from the Greek for "broad nosed", and their noses are flatter than those of other simians, with sideways-facing nostrils. Monkeys in the family Atelidae, such as the spider monkey , are the only primates to have prehensile tails . New World monkeys' closest relatives are the other simians , the Catarrhini ("down-nosed"), comprising Old World monkeys and apes . New World monkeys descend from African simians that colonized South America,

546-428: Is less comprehensive than that of the more easily observed Old World monkeys. Unlike most Old World monkeys, many New World monkeys form monogamous pair bonds , and show substantial paternal care of young. They eat fruits, nuts, insects, flowers, bird eggs, spiders, and small mammals. Unlike humans and most Old World monkeys, their thumbs are not opposable (except for some cebids ). Nostril In humans ,

588-504: Is substituted for Spider Monkey. In present-day Maya religious feasts, spider monkey impersonators serve as a kind of demonic clowns. In Classical Maya art, they are ubiquitous, often shown carrying cacao pods. Captain Simian & the Space Monkeys features a spider monkey named Spydor who is the smallest of the crew. New World monkey Incertae sedis New World monkeys are

630-534: Is the feature used most commonly to distinguish between the two groups. The clade for New World monkeys, Platyrrhini, means "flat nosed". The noses of New World monkeys are flatter than the narrow noses of Old World monkeys, and have side-facing nostrils. New World monkeys are the only monkeys with prehensile tails —in comparison with the shorter, non-grasping tails of the anthropoids of the Old World. Prehensility has evolved at least two distinct times in platyrrhines, in

672-509: The nasal cycle is the normal ultradian cycle of each nostril's blood vessels becoming engorged in swelling, then shrinking. The nostrils are separated by the septum . The septum can sometimes be deviated , causing one nostril to appear larger than the other. With extreme damage to the septum and columella, the two nostrils are no longer separated and form a single larger external opening. Like other tetrapods , humans have two external nostrils (anterior nares) and two additional nostrils at

714-407: The pygmy marmoset (the world's smallest monkey), at 14 to 16 cm (5.5 to 6.5 in) and a weight of 120 to 190 g (4.2 to 6.7 oz), to the southern muriqui , at 55 to 70 cm (22 to 28 in) and a weight of 12 to 15 kg (26 to 33 lb). New World monkeys differ slightly from Old World monkeys in several aspects. The most prominent phenotypic distinction is the nose, which

756-497: The 2n value varies from 16 in the titi monkey to 62 in the woolly monkey . A Bayesian estimate of the most recent common ancestor of the extant species has a 95% credible interval of 27  million years ago - 31  million years ago . The following is the listing of the various platyrrhine families, as defined by Rylands & Mittermeier (2009), and their position in the Order Primates: The arrangement of

798-466: The Atelidae family (spider monkeys, woolly spider monkeys, howler monkeys, and woolly monkeys), and in capuchin monkeys ( Cebus ). Although prehensility is present in all of these primate species, skeletal and muscular-based morphological differences between these two groups indicate that the trait evolved separately through convergent evolution. The fully prehensile tails that have evolved in Atelidae allow

840-525: The New World monkey families, indeed the listing of which groups consist of families and which consist of lower taxonomic groupings, has changed over the years. McKenna & Bell (1997) used two families: Callitrichidae and Atelidae, with Atelidae divided into Cebinae, Pitheciinae, and Atelinae. Rosenberger (2002 following Horowitz 1999) demoted Callitrichidae to a subfamily, putting it under the newly raised Cebidae family. Groves (2005) used four families, but as

882-568: The South American lowland forest, to evolve their unique locomotory system. This theory is not supported by fossil evidence. Other theories include Brachyteles , Lagothrix and Ateles in an unresolved trichotomy , and two clades, one composed of Ateles and Lagothrix and the other of Alouatta and Brachyteles . More recent molecular evidence suggests the Atelinae split in the middle to late Miocene (13 Ma ), separating spider monkeys from

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924-471: The adults rest while the young play. Through the rest of the day, they may feed infrequently until around 10 pm. If food is scarce, they may eat insects , leaves, bird eggs, bark and honey . Spider monkeys have a unique way of getting food: a lead female is generally responsible for finding food sources. If she cannot find enough food for the group, it splits into smaller groups that forage separately. The traveling groups have four to nine animals. Each group

966-522: The age of 61 (about twice as long as the average spider monkey). Spider monkeys eat fleshy fruits 71 to 83 percent of the time. They can live for long periods on only one or two kinds of fruits and nuts. They eat the fruits of many big forest trees, and because they swallow fruits whole, the seeds are eventually excreted and fertilized by the feces . Studies show the diet of spider monkeys changes their reproductive, social, and physical behavioral patterns. Most feeding happens from dawn to 10 am. Afterward,

1008-439: The back of the nasal cavity, inside the head (posterior nares, posterior nasal apertures or choanae ). They also connect the nose to the throat (the nasopharynx), aiding in respiration. Though all four nostrils were on the outside of the head of the aquatic ancestors of modern tetrapods, the nostrils for outgoing water (excurrent nostrils) migrated to the inside of the mouth, as evidenced by the discovery of Kenichthys campbelli ,

1050-528: The base of the Platyrrhini, as are Szalatavus , Lagonimico , and Canaanimico . Possible evidence for a third transatlantic dispersal event comes from a fossil molar belonging to Ashaninkacebus simpsoni , which has strong affinities with stem anthropoid primates of South Asian origin, the Eosimiidae . The chromosomal content of the ancestor species appears to have been 2n = 54. In extant species,

1092-563: The current estimate of the Atlantic mid-ocean ridge formation processes spreading rate of 25 millimetres per year (1 in/year)). The non-platyrrhini Ucayalipithecus of Amazonian Peru who might have rafted across the Atlantic between ~35–32 million years ago, are nested within the extinct Parapithecoidea from the Eocene of Afro-Arabia, suggesting that there were at least two separate dispersal events of primates to South America, Parvimico and Perupithecus from Peru appear to be at

1134-559: The day. Recent meta-analyses on primate cognition studies indicated spider monkeys are the most intelligent New World monkeys. They can produce a wide range of sounds and will "bark" when threatened; other vocalisations include a whinny similar to a horse and prolonged screams. They are an important food source due to their large size, so are widely hunted by local human populations; they are also threatened by habitat destruction due to logging and land clearing. Spider monkeys are susceptible to malaria and are used in laboratory studies of

1176-568: The degree to which they avoid each other during the day depends on food competition and the risk of predation. The average subgroup size is between 2 and 8 but can sometimes be up to 17 animals. Also less common in primates, females rather than males disperse at puberty to join new groups. Males tend to stick together for their whole lives. Hence, males in a group are more likely to be related and have closer bonds than females. Males also cement bonds through "grappling": prolonged hugging, face greeting, tail intertwining, and genital manipulation. However,

1218-460: The disease. The population trend for spider monkeys is decreasing; the IUCN Red List lists one species as vulnerable , five species as endangered and one species as critically endangered . Theories abound about the evolution of the atelines ; one theory is they are most closely related to the woolly spider monkeys ( Brachyteles ), and most likely split from woolly monkeys ( Lagothrix ) in

1260-451: The five families of primates that are found in the tropical regions of Mexico , Central and South America : Callitrichidae , Cebidae , Aotidae , Pitheciidae , and Atelidae . The five families are ranked together as the Ceboidea ( / s ə ˈ b ɔɪ d i . ə / ), the only extant superfamily in the parvorder Platyrrhini ( / p l æ t ɪ ˈ r aɪ n aɪ / ). Platyrrhini

1302-418: The intruder. The monkeys also defecate and urinate toward the intruder. Spider monkeys are diurnal and spend the night sleeping in carefully selected trees. Groups are thought to be directed by a lead female, which is responsible for planning an efficient feeding route each day. Grooming is not as important to social interaction, owing perhaps to a lack of thumbs. Spider monkeys have been observed avoiding

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1344-525: The largest New World monkeys and give rise to their common name. Spider monkeys live in the upper layers of the rainforest and forage in the high canopy, from 25 to 30 m (82 to 98 ft). They primarily eat fruits, but will also occasionally consume leaves, flowers, and insects. Due to their large size, spider monkeys require large tracts of moist evergreen forests, and prefer undisturbed primary rainforest. They are social animals and live in bands of up to 35 individuals, but will split up to forage during

1386-534: The more independent young to cross by pulling branches closer together. Mothers also groom their young. Male spider monkeys are one of the few primates that do not have a penis bone ( baculum ). Spider monkeys are found in many aspects of the Mesoamerican cultures. In the Aztec 260-day calendar, Spider Monkey (Nahua Ozomatli ) serves as the name for the 11th day. In the corresponding Maya calendar, Howler Monkey (Batz)

1428-443: The offspring. A mother carries her infant around her belly for the first month after birth. After this, she carries it on her lower back. The infant wraps its tail around its mother's and tightly grabs her midsection. Mothers are very protective of their young and are generally attentive mothers. They have been seen grabbing their young and putting them on their backs for protection and to help them navigate from tree to tree. They help

1470-463: The possible threat. It shakes the branches with its feet, hands, or a combination while hanging from its tail. It may also scratch its limbs or body with various parts of its hands and feet. Seated monkeys may sway and make noise. Males and occasionally adult females growl menacingly at the approach of a human. If the pursuer continues to advance, the monkeys may break off live or dead tree limbs weighing up to 4 kilograms (8.8 lb) and drop them towards

1512-520: The primates to suspend their entire body weight by only their tails, with arms and legs free for other foraging and locomotive activities. Semi-prehensile tails in Cebus can be used for balance by wrapping the tail around branches and supporting a large portion of their weight. New World monkeys (except for the howler monkeys of genus Alouatta ) also typically lack the trichromatic vision of Old World monkeys. Colour vision in New World primates relies on

1554-499: The same journey across the Atlantic, notably including caviomorph rodents. At the time the New World monkeys dispersed to South America, the Isthmus of Panama had not yet formed, so ocean currents , unlike today, favoured westward dispersal, the climate was quite different, and the width of the Atlantic Ocean was less than the present 2,800 km (1,700 mi) width by about a third (possibly 1,000 km (600 mi) less, based on

1596-578: The spider monkey's common name . Their deftly prehensile tails , which may be up to 89 cm (35 in) long, have very flexible, hairless tips and skin grooves similar to fingerprints . This adaptation to their strictly arboreal lifestyle serves as a fifth hand. When the monkey walks, its arms practically drag on the ground. Unlike many monkeys, they do not use their arms for balance when walking, instead relying on their tails. The hands are long, narrow, and hook-like and have reduced or nonexistent thumbs. The fingers are elongated and recurved. Their hair

1638-411: The strongest social bonds are between females and their young offspring. Spider monkeys communicate their intentions and observations using postures and stances, such as postures of sexual receptivity and of attack. When a spider monkey sees a human approaching, it barks loudly similar to a dog. When a monkey is approached, it climbs to the end of the branch it is on and shakes it vigorously to scare away

1680-412: The two nostrils and experience a perceptual rivalry akin to that of binocular rivalry when there are two different inputs to the two eyes. Furthermore, scent information from the two nostrils leads to two types of neural activity with the first cycle corresponding to the ipsilateral and the second cycle corresponding to the contralateral odor representations. In some cultures the extreme wide flaring of

1722-446: The upper canopy of the trees for locomotion. One researcher speculated this was because the thin branches at the tops of trees do not support the monkeys as well. At 107 grams (3.8 oz), the spider monkey brain is twice the size of the brain of a howler monkey of equivalent body size; this is thought to be a result of the spider monkeys' complex social system and their frugivorous diets, which consist primarily of ripe fruit from

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1764-572: The woolly spider monkeys and the woolly monkeys. The genus name Ateles derives from the ancient greek word ἀτέλεια ( atéleia ), meaning "incomplete, imperfect", in reference to the reduced or non-existent thumbs of spider monkeys. The genus contains seven species, and seven subspecies. Spider monkeys are among the largest New World monkeys; black-headed spider monkeys , the largest spider monkey, have an average weight of 11 kilograms (24 lb) for males and 9.66 kg (21.3 lb) for females. Disproportionately long, spindly limbs inspired

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