Primates (lat. Primates, from lat. primas, lit. "first") - one of the most progressive orders of placental mammals, including, among other things, monkeys and humans. The order includes more than 400 species

Appearance

Primates are characterized by five-fingered, very mobile upper limbs (hands), opposition of the thumb to the rest (for the majority), and nails. The body of most primates is covered with hair, and lemurs and some broad-nosed monkeys also have an undercoat, which is why their hairline can be called real fur.

general characteristics

 binocular vision

 Hairline

 five-fingered limb

 fingers are equipped with nails

·  thumb brushes are opposed to all the rest

 underdeveloped sense of smell

Significant development of the cerebral hemispheres

Classification

A detachment of primates was identified back in 1758 by Linnaeus, who attributed to him people, monkeys, semi-monkeys, bats and sloths. For the defining features of primates, Linnaeus took the presence of two mammary glands and a five-fingered limb. In the same century, Georges Buffon divided primates into two orders - four-armed (Quadrumana) and two-armed (Bimanus), separating man from other primates. Only 100 years later, Thomas Huxley put an end to this division by proving that the monkey's hind limb is a leg. Since the 18th century, the composition of the taxon has changed, but back in the 20th century, the slow loris was attributed to sloths, and bats were excluded from the closest relatives of primates in early XXI century.

IN Lately The classification of primates has undergone significant changes. Previously, suborders of semi-monkeys (Prosimii) and anthropoid primates (Anthropoidea) were distinguished. The semi-monkeys included all representatives of the modern suborder strepsirrhines, (Strepsirhini), tarsiers, and sometimes tupai (now considered as special detachment). Anthropoids became the infraorder apes in the suborder dry-nosed monkeys. In addition, the Pongidae family was previously distinguished, which is now considered a subfamily of Pongina within the Hominid family.

 suborder strepsirrhines (Strepsirhini)

 Lemuriformes infraorder

 lemurs, or lemurids (Lemuridae): actually lemurs

·  pygmy lemurs(Cheirogaleidae): dwarf and mouse lemurs

Lepilemuridae (Lepilemuridae)

 Indriidae (Indriidae): indri, avagis and sifaki

 hand-legged (Daubentoniidae): aye-aye (single species)

 Infraorder Loriformes (Loriformes)

 loris (Loridae): lorises and pottos

 Galagonidae (Galagonidae): Galago proper

 suborder dry-nosed (Haplorhini)

 infraorder tarsiiformes (Tarsiiformes)

 tarsiers (Tarsiidae)

 Infraorder Monkeys (Simiiformes)

 parvoorder broad-nosed monkeys, or monkeys of the New World (Platyrrhina)

 marmosets (Callitrichidae)

 chain-tailed (Cebidae)

 night monkeys (Aotidae)

 Saky (Pitheciidae)

 arachnids (Atelidae)

 narrow-nosed monkeys, or primates of the Old World (Catarhina)

 superfamily canine-headed (Cercopithecoidea)

 marmoset, or lower narrow-nosed monkeys (Cercopithecidae): macaques, baboons, monkeys, etc.

 superfamily great apes, or hominoids (Hominoidea), or anthropomorphids (Anthropomorphidae)

 gibbons, or lesser apes (Hylobatidae): true gibbons, nomascuses, huloks and siamangs

 hominids (Hominidae): orangutans, gorillas, chimpanzees and humans

It is assumed that primates evolved from primitive insectivores in the Upper Cretaceous in Asia, from where they subsequently spread to other continents. Now the order includes about 200 species distributed in the tropics of Asia, Africa and America and divided into two suborders: semi-monkeys(Prosimii) and higher primates(Anthropodidae).

Suborder Lower primates, or Semi-monkeys (Prosimii)

This suborder includes the most primitive representatives of primates - stupid , lemurs And tarsiers . They are common in Southeast Asia, Indonesia, Madagascar and the African tropics. Now 53 species are known.

Relatively small animals with a body length of 9 to 106 cm. The tail is often long (in some species twice as long as the body), but not prehensile, densely pubescent. Not all types first finger clearly resists other fingers. Most of the fingers are armed not with nails, but with claws. The surface of the brain is smooth or furrowed.

Family tupai (Tupaiidae) are the most primitive of the prosimians. Small animals (body length 10 - 22 cm) with a long fluffy tail. Outwardly, they look like small squirrels. Their first fingers are not opposed to the rest. Widespread in the forests of Southeast Asia.

Family species lemurs (Lemuridae) - inhabitants of Madagascar and neighboring islands. These are nocturnal arboreal animals that feed on fruits, insects, many are omnivores. Their body is covered with thick fur, the tail is also long and fluffy. Herd lifestyle. Ordinary lemurs are mobile creatures, easily tamed, not uncommon in zoos. known lemurs (Lemur variegatus), catta (L. catta), murine (Cheirogalens). close to lemurs hand-footed or aye-aye (Daubentoniidae), lorizidaceae (Lorisidae).

To the family tarsiers (Darsiidae) belong to peculiar animals a little larger than a rat, with huge eyes directed forward, very long hind legs and short front legs. Fingers are equipped with suction pads. Arboreal nocturnal animals that feed on insects. Distributed on the islands of the Malay Archipelago. Representative - tarsier – ghost (Tarsius spectrum).

Suborder Higher primates, or Monkeys (Anthropoidea)

Monkeys are larger than the species of the previous suborder, their body length is from 15 to 200 cm. Tail missing or developed to varying degrees; many South American species prehensile. First fingerclearlyopposed to the rest. All fingers are armed nails. The brain is relatively larger than that of prosimians, and anterior hemispherebrain in the vast majority of specieshave numerous furrows and convolutions.

The suborder includes three superfamilies: broad-nosed(American), monkeys (Ceboidea), narrow-nosed(Afro-Asiatic) monkeys (Cercopithecidae) and higher(Hominoidae). About 140 species of monkeys are now known. Broad-nosed New World monkeys are distinguished by their wide cartilaginous nasal septum and outward-facing nostrils.. The tail is long, tenacious, grasping, arboreal way of life.

Family marmosets , or marmosets monkeys (Callithricidae), includes the smallest representatives of higher apes. The length of their body is 15 - 20 cm. The tail is long, but not grasping.

Family prehensile-tailed monkeys, or cebid (Cobidae) includes small and medium-sized species (body length 24–91 cm). The tail of all species is well developed: in many it is tenacious. Among the species of this family, we mention spider monkeys(genus Brachytelos), capuchins (celebrity) And howler monkeys (Alonatta).

The species of both families are forest, tree animals. Their food is mixed, but mostly vegetable. They tend to be kept in family groups. Distributed in Central and South America.

Superfamily lower narrow-nosed monkeys (Cercopithecidae) unlike American have a narrow nasal septum And protruding front of the skull. They are common in Africa and South Asia.

Family monkeys (Cercopithecidae), is the most numerous group of narrow-nosed monkeys. They have highly developed cheek pouches; usually has a long tail and developed ischial calluses. Biologically very diverse. Actually monkeys(Cercopithecus) are predominantly African species that inhabit tropical forests and keep in herds. They lead a mostly arboreal lifestyle. Herbivorous. Baboons (Papio) are also common in Africa, they usually live in rocky mountains and nest in caves. Their diet is mixed. Some species attack mammals. macaques(genus Macaca) are predominantly South Asian monkeys. They lead both arboreal and terrestrial lifestyles; often, like baboons, they live in the mountains, adhering to rocky slopes. Most famous rhesus monkey (M. mulatta), common in South Asia and the Himalayas (from Nepal to Burma). They live in large herds. Common in zoos around the world.

Superfamily higher, or humanoid, primates (Hominiodae) unites gibbons , great apes And human .

In the family gibbons (Hylobatidae) seven species characterized by very long forelimbs: when upright, they reach the feet of the hind limbs. Common in tropical forests Northeast India, Indochina, Java, Sumatra and Kalimantan. Typical inhabitants of tree crowns. Swinging on their front legs, they jump from tree to tree at a distance of 10 m or more. The largest kind gibbon hulok (Hylobates hoolck), found in India and Burma.

In the family great apes four types. According to the features of the anatomical structure and a number of physiological indicators, they are closest to humans. The cerebral box of the skull is especially strongly developed. The hemispheres of the forebrain have complex furrows and convolutions.

orangutan (pongo pygmaeus) - a large (1.5 m high) hairy monkey of a reddish-red color, with elongated jaws, very long forelimbs and small auricles. Distributed on the islands of Sumatra and Kalimantan. It leads an arboreal lifestyle, descending to the ground extremely rarely. Orangutans live alone or in family groups. The young are born in a nest in a tree. Their numbers have declined sharply and continue to decline. The species is included in the IUCN Red List.

Chimpanzee (Pan troglodytes). They live in the tropical forests of Africa. The way of life is mainly arboreal, but descend to the ground regularly. Their dimensions are about 1.5 m. The general coloration is black; the face is naked; the ears are comparatively large, very similar to those of humans. The front legs are relatively shorter than those of the orangutan. Mostly vegetarians. They live in families, sometimes gathering in small herds.

Gorilla (Gorilla gorilla) - the largest of the great apes (2 m high). The forelimbs, like those of a chimpanzee, are not very long. They walk on the ground, bent over, leaning (like chimpanzees) on all four limbs. They feed on fruits, nuts and root vegetables. Widespread in the forests of equatorial Africa.

Family of people (Hominidae) includes one living species Homo sapiens ( Homo sapiens). There are many features that distinguish humans from anthropoid apes. The human brain, with a well-developed cerebral cortex, is more than three times the size of an ape's brain. The hairline is reduced. The forelimbs are relatively short, not reaching to the knees. body position is upright and hands are freed from the function of supporting the body. Hind limbs straightened in knee joint And lost grasping function. Due to the vertical position of the body wide pelvis, serving to support the viscera and strongly developed gluteal muscles. The chin has a characteristic protrusion associated with a large and complex tongue.

The primate order is divided into two suborders and 16 families:

Suborder Wet Nose ( Strepsirrhini) includes the following families:

  • Dwarf lemurs ( Cheirogaleidae);
  • Lemurs ( Lemuridae);
  • Lepilemory ( Lepilemuridae);
  • Indriaceae ( Indriidae);
  • Hand-legged ( Daubentoniidae);
  • Loriaceae ( Loridae);
  • Galagic ( Galagonidae).

Suborder Dry-nosed ( Haplorrhini) consists of the following families:

  • Tarsiers ( Tarsiidae);
  • Igrunkovye ( Callitrichidae);
  • chain-tailed monkeys ( Cebidae);
  • night monkeys ( aotidae);
  • Sakov ( Pitheciidae);
  • Spider Monkeys ( Atelidae);
  • Monkey ( Cercopithecidae);
  • Gibbons ( Hylobatidae);
  • hominids ( Hominidae).

Evolution

Fossils of early primates are from the early (56 to 40 million years ago) or possibly the late Paleocene (59 to 56 million years ago). While they are an ancient group, and many (especially the broad-nosed or New World monkeys) have remained fully arboreal, others have become at least partially terrestrial and have achieved a high level of intelligence. There is no doubt that this particular detachment includes some of the.

Lifespan

Although humans are the longest-lived primates, the potential lifespan of chimpanzees is estimated at 60 years, and orangutans sometimes reach that age in captivity. On the other hand, the lifespan of lemurs is about 15 years, while that of monkeys is 25-30 years.

Description

Roxellan rhinopitecus

Despite notable differences between primate families, they share several anatomical and functional characteristics that reflect them. general detachment. Compared to body weight, the primate brain is larger than that of other mammals and has a unique spur-like groove that separates the first and second visual areas on each side of the brain. While all other mammals have claws or hooves on their fingers, primates have flat nails. Some primates have claws, but the thumb still has a flat nail.

Not all primates have equally nimble hands; only narrow-nosed monkeys (marmosets and hominids, including humans), as well as some lemurs and lorises, have an opposable thumb. Primates are not the only animals that grasp objects with their limbs. But since this characteristic is found in many other arboreal mammals (such as squirrels and opossums), and since most modern primates are arboreal, it is assumed that they evolved from an ancestor that was arboreal.

Primates also have specialized nerve endings on their limbs that increase tactile sensitivity. As far as is known, no other placental mammal has them. Primates have fingerprints, but so do many other arboreal mammals.

Primates have binocular vision, although this feature is by no means limited to primates, but it is a common characteristic seen among . Therefore, it has been proposed that the ancestor of primates was a predator.

Primate teeth differ from those of other mammals by having low, rounded molar and premolar teeth that contrast with long teeth. sharp teeth other placental mammals. This difference makes it easy to recognize primate teeth.

Size

Members of the primate order show a range of sizes and adaptive diversity. The smallest primate is the mouse lemur ( Microcebus berthae), which weighs about 35-50 grams; the most massive primate is, of course, the gorilla ( Gorilla), whose weight varies from 140 to 180 kg, which is almost 4000 times the weight of the mouse lemur.

Geographic range and habitat

Primates occupy two main vegetation zones: and. Each of these zones created appropriate adaptations in primates, but among tree species, perhaps more variety of bodily forms than among the inhabitants of the savannah. Arboreal primates have many of the same characteristics that likely evolved as adaptations to life in trees. Several species, including our own, have left their trees to become terrestrial.

Non-human primates have a wide distribution throughout tropical latitudes, India, Southeast and . In Ethiopia, gelada (genus Theropithecus) is found at altitudes up to 5000 meters. The gorillas of the Virunga Mountains are known to pass through mountain passes at over 4,200 meters. Red Howlers ( Alouatta seniculus) Venezuelans live at an altitude of 2500 meters in the mountains of the Cordillera de Merida, and in northern Colombia, the Mirikins (genus Aotus) are found in the tropical mountain forests of the Central Cordillera.

The gestation period varies among primate species. For example, mouse lemurs have a gestation period of 54-68 days, lemurs 132-134 days, macaques 146-186 days, gibbons 210 days, chimpanzees 230 days, gorillas 255 days, and humans (on average) 267 days. Even in small primates, the gestation period is significantly longer than in other mammals of equivalent size, reflecting the complexity of primates. Although primates have The general trend to the evolutionary increase in body size, there is no absolute correlation between body size and the length of the gestation period.

The degrees of puberty and maternal dependence at birth appear to be closely related. Newborn primates are not as helpless as kittens, puppies or rats. With few exceptions, the young primate is born with open eyes and wool. Cubs should be able to cling to their mother's fur; only a few species leave their babies in shelters while feeding. The young of the highest primates are able to cling to their mother's fur unaided; however, humans, chimpanzees, and gorillas must support their newborns, and humans do so the longest.

Once the primate infant has learned to support itself by standing on its two (or four) legs, the physical dependency phase is over; next stage, psychological dependence, lasts much longer. The human child is attached to the mother for a much longer time than the non-human primate. The adolescent period of psychological maternal dependence is 2.5 years in lemurs, 6 years in monkeys, 7-8 years in most hominoid, and 14 years in humans.

Behavior

Primates are among the most social animals, forming pairs or family groups. Social systems are influenced by three main environmental factors: distribution, group size, and predation. As part of social group there is a balance between cooperation and competition. Cooperative behavior includes social grooming, food sharing, and collective defense against predators. Aggressive behavior often signals competition for food, sleeping quarters, or helpers. Aggression is also used to establish dominance hierarchies.

It is known that several species of primates can cooperate in wild nature. For example, in national park Tai, in Africa, several species coordinate behavior to protect themselves from predators. These include Diana monkey, Campbell's monkey, lesser white-nosed monkey, red colobus, king colobus, smoky mangobey. Among the predators of these monkeys is the common chimpanzee.

Primates have developed cognitive abilities: some make tools and use them to obtain food and for social display; others have complex hunting strategies requiring cooperation, influence and dominance; they are status conscious, manipulative and deceitful; these animals can learn to use symbols and understand human language.

Some primates rely on olfactory cues for many aspects of social and reproductive behavior. Specialized glands are used to mark territories with pheromones that are picked up by the vomeronasal organ. Primates also use vocalizations, gestures, and emotions to convey psychological state. Like humans, chimpanzees can distinguish between familiar and unfamiliar faces.

Primate conservation

While many primates are still abundant in the wild, populations of many species are in sharp decline. According to International Union Conservation Agency (IUCN), more than 70% of primates in Asia and approximately 40% of primates in South America, the African mainland and the island of Madagascar are listed as endangered. A number of species, especially the gorilla, some of Madagascar lemurs and some species from South America, are in serious danger of extinction as their habitats are being destroyed and poaching is rampant.

However, some endangered species have increased in numbers. A concerted captive breeding effort has been successful, and reintroduction into the wild is also practiced in Brazil.


Primates are a group of animals that, for the most part, biological characteristics do not differ from modern human populations, and its evolutionary paths diverged from the paths of man later than all other animals. The shared characteristics of humans and primates serve both as proof of human evolution and as a source of ideas and doubt. Primates provide a context for the study of human evolution. Primates are a class of mammals characterized by the retention of some primitive traits and the progressive development of more specialized traits associated with an arboreal lifestyle and a high degree specializations.

Characteristic features of primates

It often happens like this: the description of any group of mammals looks unsuccessful. A formal enumeration of features does not give the reader any idea about the object. However, the most boring description of primates, given in 1873 by the English biologist Jackson Myvart, is also the most reliable: "Placental mammals with claws and clavicle, orbits surrounded by bone, all three types of teeth; pituitary gland with posterior lobe and spur groove; inner finger, along on at least one pair of limbs opposed to the rest; thumb with or without broad nail; caecum well developed; penis hanging down; testicles in scrotum; two mammary mammary glands. And although this description does not capture the true beauty of primates and does not give an idea of ​​\u200b\u200btheir amazing lifestyle, it remains nevertheless the most accurate. Modern scholars can add only two strokes to this portrait: "the shortened nose of the muzzle and the flat face provide good spatial and color vision, and a relatively large brain with a developed cerebral cortex causes complex behavior.

This description is very general. There are primates that lack this or that feature. On the other hand, some of the features mentioned are also found in other groups of animals. For example, many mammals have clavicles and three types of teeth.

The order Primates belongs to the class of mammals, the subtype of vertebrates, the type of chordates. The following features are characteristic of the chordate type:

1. The skeleton is formed by a chord - a highly vacuolated connective tissue - which is necessarily present at least at one of the stages of ontogenesis, for example, in embryogenesis;

2. Central nervous system - in the form of a tube with a slit;

3. In front of the digestive tube - the pharynx - there are gill slits;

4. Typical for all chordates overall plan structures of organ systems: the intestine is under the chord, and it is under the neural tube.

In addition, all chordates have features that make them related to invertebrates - this is bilateral symmetry and a secondary mouth. A typical representative of the simplest chordates lancelet. The vertebrate subtype includes the following classes: fish, amphibians, reptiles, birds and mammals. All of them are united by the presence of the jaw apparatus, active image life, that is active search food and sexual partner. With active movement, limbs appear: in fish, these are fins, and in other representatives, the limbs of a five-fingered. In connection with orientation, the sense organs, the brain and spinal cord develop, and the skull and spine that protect them appear. All vertebrates have an intensive metabolism, a closed circulatory system, a heart, respiratory and excretory organs.

The class of mammals is characterized by live birth, carrying a cub in the uterus and feeding it with milk. Mammals have dental system With different types teeth, reflecting their food specialization - incisors, canines, premolars and molars. Milk teeth are replaced by permanent ones. All mammals are homoiothermic (this is with a constant body temperature) animals with a high level of metabolism. Their body is covered with hair, which are derivatives of the skin. Females have mammary glands. All mammals, in addition to the inner and middle, also have an outer ear.

The structure of the skeleton of the representatives of the detachment

The four-legged lemurs, as well as most monkeys like monkeys, have retained the original structure of the ancient primates. They have a long back, short and narrow rib cage, long and thin femurs, hind limbs are not shorter than the front ones. These animals live mainly on trees, running or jumping along the branches. The long tail plays the role of a rudder or balancer during jumps. Terrestrial monkeys, such as baboons, usually have much shorter tails.

Great apes and sluggish prosimians do not have tails. In orangutans and others great apes the back is shorter, the chest is wider, the pelvic bones are stronger. These are traits associated with an upright posture. The arms are longer than the legs, especially in species such as gibbons and orangutans, which move by swinging their arms (brachiation).

The structure of the arms and legs in primates is associated with their lifestyle (Fig. 1):

1. The hand of a spider monkey with a very short thumb is characteristic of species that move with the help of arm swings. 2. Gibbon: The short, opposed thumb is away from the others involved in the brachiation grip. 3. Gorilla: the thumb on the hand is opposed to the rest, which contributes to the accuracy of manipulation. 4. Macaques: The short, opposed thumb allows the animals to rest on the ground with an open palm. 5. Tamarin: a long foot and claws on all fingers, except for the big one, are characteristic of all species clinging to tree branches (in other monkeys, all fingers are equipped with flat claws). 6 Siamang and 7 Orangutan: wide foot with long, grippy thumb, good for climbing. 8. Baboon: long graceful foot is convenient for moving on the ground.

Rice. 1 Limbs of primates

The jaws of the insectivorous ancestors of primates were armed with numerous pointed teeth (Fig. 2). In strepsirrhines such as lemurs (1), the first lower premolar is shaped like a canine, and the surfaces of the lower incisors and canines lie in the same plane, forming a toothcomb similar to that of the galagos. Galago use this comb during feeding and grooming. In leaf-eating monkeys of the Old World, for example, thin-bodied (2), the surface of the molars is, as it were, divided into squares by four sharp protrusions connected by oblique ridges - a good tool is obtained for grinding roughage. In great apes, in particular in the gorilla (3), the lower molars have five protrusions, and the ridges have a complex shape.


Rice. 2. General form teeth different types primates

Anatomical and physiological features detachment

Primates are medium-sized mammals. They are larger than insectivorous and bats, smaller than most ungulates and cetaceans. Their body weight ranges from 30 g (in the gray mouse lemur) to 150 kg or more (in male gorillas). Like other mammals, large primate species breed less frequently but live longer than their smaller relatives.

Mouse lemurs are able to breed already at the age of one year and every year give birth to 2 cubs weighing 6.5 g after a 2-month pregnancy. The longevity record for a mouse lemur is 15 years. On the contrary, the female gorilla becomes sexually mature only by the age of 10 years. She gives birth to one cub weighing 2.1 kg after 9 months of pregnancy and can become pregnant again only after 4 years. Gorillas usually live up to 40 years.

With significant species differences, a small offspring is common to all species of monkeys: the female gives birth to only one or two cubs at a time.

The growth rate of young animals in primates is also low, much lower than in other mammals with a similar body weight. The reason for this difference is unclear, but may be related to brain size. Brain tissues are the most energy intensive in the body. A high level of metabolism in the brain in large primates reduces the rate of body growth and the development of reproductive organs.

Due to low reproduction rates, primates have a rather strong propensity for infanticide. It is not uncommon for males to kill offspring born by a female to other males, as the lactating female is unable to conceive again. Males, even at their peak physical development, are limited in their attempts to reproduce and do everything possible to preserve their genotype. So, the male monkey Hanuman has only 800 days to procreate out of 20 years of life.

Body weight differs not only in different primates, but also in males and females of the same species. Males are usually larger than females (although there are many exceptions to this rule).

In some monkeys, the family consists of one male and several females. Since body weight gives the male an advantage in a duel with his own kind, there is a natural selection for an increase in body weight. The male Hanuman sometimes gathers a harem of 20 females, whom he has to protect from the encroachments of other males. The body weight of the harem owner can be 160% of the female's weight. In contrast, in species whose males usually mate with only one female (gibbons), the sexes do not differ in size. Sexual dimorphism in lemurs is very weakly expressed. These animals live in groups, like other primates. Scientists suggest that the social structure in these animals is different from that of other primates.

Not only the size of the body plays a role in the tough struggle for paternity. Fangs are powerful weapons, which are used by males in fights and aggressive demonstrations. In addition, there are more sophisticated ways to defeat the enemy. There are species in which several males fertilize one female. The winner is the one who has large testicles and is able to produce more sperm. This increases the likelihood of fertilization of the egg by the sperm of the record-breaking male.

Sexual competition is reflected not only in the morphology of males. In many female primates, breeding cycles are accompanied by periodic reddening and swelling of the skin in the anagenital region. Such a pattern, clearly visible from afar, becomes most vivid on the days of ovulation. This phenomenon is typical for species living in large mixed groups. Females with swollen flesh are most attractive to males. Although females tend to mate with stronger and larger males, they attract everyone, even young ones. Ultimately, this reduces the likelihood of infanticide: even a small chance of participating in reproduction prevents males from trying to kill other people's cubs. So important is swollen flesh as a signal of readiness to reproduce that female geladas, whose anagenital area is poorly visible because these monkeys feed while sitting, have evolved skin with the same function on the chest.



The class of mammals is characterized by live birth, feeding the cub with milk, carrying it in the uterus. All representatives of this class are homoiothermic, that is, their body temperature is constant. In addition, their metabolic rate is high. In addition to the middle and inner ear, all mammals also have an outer ear. Females have mammary glands.

Primates (semi-monkeys and monkeys) of all mammals are perhaps the greatest richness and variety of forms. However, despite the differences between them, many structural features of their bodies are similar. They have developed in a long process of evolution as a result of an arboreal lifestyle.

Primate limbs

Primates are animals with a five-fingered grasping limb, well developed. It is adapted to the climbing of the representatives of this detachment along the branches of trees. All of them have a clavicle, and the ulna and radius are completely separated, which provides a variety of movements and mobility of the forelimb. The thumb is also movable. It can be contrasted in many species with the rest. The terminal phalanges of the fingers are provided with nails. In primate forms that have claw-like nails, or those that have claws on only some of the fingers, the thumb is characterized by the presence of a flat nail.

The structure of primates

When moving on the surface of the earth, they rely on the entire foot. In primates, a reduction in the sense of smell is associated with tree life, as well as good development organs of hearing and vision. They have 3-4 turbinates. Primates - whose eyes are directed forward, the eye sockets are separated from the temporal fossa by the periorbital ring (lemurs, tupai), or by a bone septum (monkeys, tarsiers). In lower primates, there are 4-5 groups of vibrissae (tactile hairs) on the muzzle, in higher ones - 2-3. In monkeys, as well as in humans, skin ridges are developed on the entire plantar and palmar surface. However, the semi-monkeys have them only on the pads. The variety of functions that the forelimbs have, as well as the active life of primates, led to a strong development of their brain. And this means an increase in the volume of the skull in these animals. However, only higher primates have large, well-developed cerebral hemispheres with many convolutions and furrows. In the lower ones, the brain is smooth, there are few convolutions and furrows in it.

Hairline and tail

In species of this order, the hairline is thick. Prosimians have an undercoat, but in most primates it is poorly developed. The coat and skin of many species are brightly colored, the eyes are yellow or brown. Their tail is long, but there are also tailless and short-tailed forms.

Nutrition

Primates are animals that feed mainly on a mixed diet, in which plant matter predominates. Some species are insectivorous. The stomach in primates, due to the mixed type of nutrition, is simple. They have 4 types of teeth - canines, incisors, large (molars) and small (premolars) molars, as well as molars with 3-5 tubercles. A complete change of teeth occurs in primates, it applies to both permanent and milk teeth.

Body dimensions

Significant variations are noted in the body size of representatives of this order. The smallest primates are mouse lemurs, while the growth of gorillas reaches 180 cm and above. The body mass of males and females differs - males are usually larger, although there are many exceptions to this rule. The family of some monkeys consists of several females and a male. Since body weight is an advantage for the latter, there is a natural selection associated with its increase. For example, a male Hanuman can assemble a whole harem of 20 females - a very large family. Primates are forced to guard their harem from other males. At the same time, in the owner of the family, the body weight reaches 160% of the female's weight. In other species, in which males usually mate with only one female (for example, gibbons), representatives of different sexes do not differ in size. very weakly expressed in lemurs.

When fighting for fatherhood important role play not only the size of the body in such a detachment as primates. These are animals whose fangs serve them powerful weapon. Males use them in aggressive displays and fights.

Primate reproduction and offspring

Primates breed all year round. Usually one calf is born (in lower forms there may be 2-3). large species Primates breed less frequently, but live longer than their smaller relatives.

Already at the age of a year, mouse lemurs are able to breed. Every year, two cubs are born. The body weight of each of them is about 6.5 g. Pregnancy lasts 2 months. 15 years is a longevity record for this species. The female gorilla, on the contrary, becomes sexually mature only by the age of 10. One cub is born, whose body weight is 2.1 kg. Pregnancy lasts 9 months, after which a second pregnancy can occur only after 4 years. Gorillas usually live up to 40 years.

Common to different, with significant species differences, is a small offspring. The growth rates of young animals in representatives of this order are very low, much lower than those observed in other mammals with a similar body weight. It is difficult to say what is the reason for this peculiarity. Perhaps it should be sought in the size of the brain. The fact is that the brain tissues are the most energy-intensive in the body. In large primates, it is observed high level metabolism, which reduces the rate of development of reproductive organs, as well as body growth.

prone to infanticide

In primates, due to low rates of reproduction, a tendency to infanticide is expressed. Often, males kill the cubs that the female gave birth to other males, since the lactating individual cannot conceive again. Males that are at the peak of their physical development are limited in their breeding attempts. Therefore, they do everything possible to preserve their genotype. A male monkey, for example, Hanuman, has only 800 days out of 20 years of life to procreate.

Lifestyle

The primate order is generally tree-dwelling, however there are semi-terrestrial and terrestrial species. Representatives of this detachment have a daytime lifestyle. Usually it is gregarious, rarely solitary or paired. They mainly live in the subtropical and tropical forests of Asia, Africa and America, and are also found in high mountain areas.

Primate classification

About 200 species of modern primates are known. There are 2 suborders (monkeys and semi-monkeys), 12 families and 57 genera. According to the classification, the most common at present, the primate order includes tupai, forming an independent family. These primates, together with tarsiers and lemurs, form a suborder of semi-monkeys. They connect through lemurs with modern primates, recalling what kind of ancestors the latter had in ancient times.

Primates: evolution

It is believed that the ancestors of modern primates were insectivorous primitive mammals, similar to the tupai that exist today. Their remains were found in Mongolia, in the Upper Cretaceous deposits. Apparently, these ancient species lived in Asia, from which they settled in other places North America and the Old World. Here these primates developed into tarsiers and lemurs. The evolution of the original forms and the New World, apparently, was from primitive long-legged creatures (some authors consider ancient lemurs to be the ancestors of monkeys). Independently of the apes found in the Old World, American primates arose. Their ancestors from North America penetrated into South. Here they specialized and developed, adapting to an exclusively arboreal lifestyle. In many biological and anatomical ways, humans are superior primates. We constitute a separate family of people with the genus man and only one species - the modern intelligent.

The practical importance of primates

Modern primates are of great practical importance. Since ancient times, they have attracted the attention of man as funny living creatures. Monkeys were the subject of hunting. In addition, these mammals were put up for sale for home entertainment or in the zoo. Primates are even eaten today! Aborigines still eat the meat of many monkeys today. The meat of the semi-monkeys is also considered very tasty. skins certain types used today for dressing various things.

A detachment of primates in last years acquires everything greater value in medical and biological experiments. These animals show great resemblance to humans in many anatomical and physiological features. And not only great primates have this similarity, but also lower ones. Representatives of this detachment are even susceptible to the same diseases that we are (tuberculosis, dysentery, diphtheria, poliomyelitis, tonsillitis, measles, etc.), which proceed in general in the same way as we do. That is why some of their organs are used today in the treatment of people (in particular, the kidneys of green monkeys, macaques and other monkeys - a nutrient medium for growing viruses, which, after appropriate processing, then turn into a polio vaccine).