A crocodile has conical teeth. Features of the internal structure of crocodiles
Amulet pendant with crocodile tooth
The line of teeth and fangs of wild animals is being replenished. And for your attention, we offer an amulet pendant with a crocodile fang from Australia from the Northern Territory state, where the film about the Dundee crocodile was filmed. Crocodile fang length 23, 32, 35.40 mm. Amulet pendants made from crocodile fang are made of 925 sterling silver.
As everyone knows, the crocodile is the master of the rivers, which has always inspired fear and horror in the local residents. Since ancient times, Indians have revered the crocodile for its strength, power, swiftness, fearlessness and ruthlessness. Therefore, the Indians still wear a crocodile tooth with great honor on their necks, as a talisman, a talisman to give physical and moral strength, it also helps to release sexual energy.
The crocodile symbolizes the night, the Moon, secrecy, rivers, death, pretense, ruthlessness, insensibility, gluttony, fertility, intelligence, exoticism. In many ancient myths, the crocodile is the support and mover of the Earth, a nocturnal deity, combining the symbolism of life and death, night and morning - a container of transcendental vital forces.
The crocodile was revered in ancient Egypt, as an image associated with water, the Sun, fertility.
Also, the crocodile was one of the emblems of the “land of the dead”. The crocodile meant the tyranny of power, the persecution of the small and weak.
As you know, a female crocodile lays 60 eggs, which take 60 days to hatch! The number 60 is a Babylonian number; the Babylonians used a sexagesimal number system associated with astrology.
Among the ancient Jews, the crocodile is a container of evil, an unholy creature.
Among the ancient Arabs - a judge, a sorcerer.
For Christians it is a demon, wisdom, possessor of the gift of foresight.
In medieval times, the crocodile meant gluttony and thirst. In art, the crocodile sculpture was depicted with its mouth bandaged, which signified the time of Lent. The crocodile was a symbol of lust and voluptuousness. The crocodile tooth was regarded as an amulet promoting male potency.
Everyone knows the phrase “crocodile tears.” It means hypocrisy, false sympathy, and speaks of people who show sympathy for a misfortune that they themselves caused. And another decoding of the phrase is that the crocodile is supposedly crying, arousing pity from the new victim in order to grab her.
So, we can summarize the meaning of the crocodile symbol.
The crocodile is the abode of hell, and at the same time of recovery and resurrection. Since in ancient times and to this day potions are made from crocodile parts, medicines. And women smeared crocodile droppings on their faces to prevent rejuvenation.
Crocodile - symbol mortal danger, betrayal, ambush, destruction, unpredictable killer.
The crocodile is the lord of life and death, a symbol of mystery, mystery, occult knowledge, light and darkness. In astrology, the crocodile is a symbol of the zodiac sign Capricorn. Prominent representatives of this sign:
Howard Hughes Jr. - December 24, 1905 Alexander Kolchak - November 16, 1874 Walt Disney - December 5, 1901 Alexey Petrenko - March 26, 1938 Woody Allen - December 1, 1935 Federico Fellini - January 20, 1920 Vladimir Vysotsky - 25 January 1938 Thaddeus Bellingshausen - September 20, 1778 Pyotr Leshchenko - June 3, 1898 Vladimir Mayakovsky - July 19, 1893
People born under the sign of the Crocodile feel dreams, magic and mystery immeasurably deeper than their individuality, their “I”.
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Among the most dangerous predators in the world, crocodiles occupy one of the first places ( Latin name– Crocodilia) are the only surviving descendants of dinosaurs, which belong to the order of aquatic vertebrates. Average length adult ranges from 2 to 5.5 meters, and the mass of a crocodile can reach 550-600 kilograms.
External structure of a crocodile
The structural features of crocodiles, both internal and external, help them survive in incredible conditions. It is interesting that, despite the long process of evolution, these reptiles have retained almost all the features of their ancestors, in particular the body of a crocodile , adapted to aquatic environment habitat:
Few people know that the body of a crocodile can have different colors, although, as a rule, the color of a crocodile is greenish-brown. Upper part The skin consists of rows of extremely strong and tightly connected horny plates that grow along with the individual itself, so that they do not shed. The color of crocodile skin can vary depending on external factors, A more precisely temperatures environment. These animals are cold-blooded, therefore normal temperature The crocodile's body angle varies between 30 and 35 degrees.
Crocodile teeth
Representatives of this species are often confused with alligators, although in reality they have a whole series differences, the main of which is the location and structure of the dentition. For example, if the jaws of a crocodile are closed, you can see the 4th tooth from the bottom, whereas in an alligator they are all closed. The total number of teeth in a crocodile is from 64 to 70, depending on the variety, and they have the same conical shape and are hollow. inner surface, where new incisors develop. On average, each crocodile's fang is replaced once every two years, and over the course of a lifetime there can be up to 45-50 such updates. In turn, the crocodile’s tongue is completely fused to the lower jaw, so some generally think that reptiles do not have this organ. 
Despite the fact that the crocodile's mouth looks very scary, in fact its teeth are not designed for chewing food, so it swallows its prey in large pieces. Digestive system crocodile has a number of specific features, for example, the stomach has very thick walls, and to improve digestion it contains stones (gastroliths). Their additional function– change the center of gravity to improve swimming performance.
Features of the internal structure of crocodiles
In general, the internal structure of the crocodile is similar to the structure of other reptiles, but there are some unusual features. For example, the skeleton of a crocodile is very similar to the structure characteristic of dinosaurs: two temporal arches, a diapsid skull, etc. The most vertebrae are found in the tail (up to 37), while in cervical spine and the body there are only 9 and 17, respectively. For additional protection, there are ribs in the abdominal part that are not connected to the spine.
The crocodile's respiratory system is created in such a way that the animal feels comfortable both on land and under water. The crocodile's respiratory organs are represented by choanae (nostrils), a nasopharyngeal passage with a secondary bony palate, a velum palatine, a trachea and lungs with a diaphragm. The very powerful and complex lungs of a crocodile are capable of holding a large volume of air, while the animal can, if necessary, adjust its center of gravity. To prevent the crocodile's breathing from interfering with its ability to move quickly, there are special muscles in the diaphragm area. 
Unique in its own way circulatory system crocodile, which is much more perfect than that of other reptiles. Thus, the crocodile’s heart is four-chambered (2 atria and 2 ventricles), and a special mechanism for mixing blood from arteries and veins makes it possible to regulate the blood supply process. If you need to speed up the digestion process, the structure of the crocodile’s heart allows you to change arterial blood to venous blood, which is more saturated with carbon dioxide and promotes the production of additional gastric juice. It should also be noted that crocodile blood has increased content antibiotics, and hemoglobin is saturated with oxygen and works independently of red blood cells.
By the way, bladder these predators do not, but to search for a mate during the breeding season there are special glands on the lower half of the jaw, which emit a musky odor.
Their nervous system is very developed, in particular, the crocodile’s brain (or rather, cerebral hemispheres) is covered with bark, and among the sensory organs, hearing and vision are especially developed. We can say with confidence that the crocodile’s memory is very good, since it manages to remember the paths along which other animals go to the watering hole.
Crocodiles are considered one of the largest types of reptiles throughout the world. They differ very strongly skin and features of the legs. The entire body consists of large horny scutes and bony plates that form the carapace. Crocodiles are very large reptiles, the form of which has survived to this day. They are descendants of dinosaurs. Characteristics for any species of these reptiles are as follows: they have fairly short but very strong legs, they have a head triangular shape, elongated muzzle, very strong and tenacious jaws, unique sharp teeth and black eyes. The shape of their legs does not prevent them from getting food both underwater and on land. The shape of the body promotes fast swimming in water; the strong and powerful tail plays the role of a control and motor organ. Most often, crocodiles are greenish-dark in color. They can change skin color. It all depends on what water they live in and what temperature it is. environment. The warmer it is outside, the greener their skin may become. Their lifespan is very long. They can live 60 years. Most long term, known to science, that's 100 years.
Features of reptiles
Crocodiles breathe using their nostrils, which are located at the top of their jaws. They can even breathe underwater. Therefore, they can be seen swimming in the water with their upper mouth raised. The crocodile's mouth is very wide and has large number unique sharp and sharpened teeth. Each tooth can be up to 5 cm. If a tooth is lost, a new one will soon grow in its place. Throughout the life of a reptile, this process of changing teeth occurs continuously. With the help of their teeth, they cannot chew very well, so in search of food, they rush as fast as they can after their prey, tear it into pieces, tear it apart and swallow it. If the prey is small, predators immediately swallow it, and if the size is large enough, they drag it away and drown it under water. Because they have no lips, their mouths cannot close. Their peculiarity is the presence of a palatine curtain, which, when diving, does not allow water to get inside. Very often, stones and other similar objects are found in the stomachs of crocodiles. Scientists believe that they need them for the relationship between the center of gravity and a convenient swimming process. In search of food, reptiles can come onto land and for a long time wander. They can watch their prey from the side, showing only their eyes from the water.
Thanks to special valves, the crocodile's ears are closed and protected eardrums underwater. These reptiles have good and sensitive hearing and sharp vision. Despite the peculiarity of the legs of these species, they can quickly climb out of the water to a sufficient height and run along the shore in search of food. Body temperature is about 30 degrees. In hot weather, they crawl under water. At night they are most often in the water. If it's cold, they try to crawl ashore to warm themselves. The forelimbs consist of 5 fingers, the hind limbs of 4, and between all the fingers there is a membrane membrane. The footprints of crocodiles can be easily distinguished from other animals. Determining where a reptile is underwater is difficult for even the most experienced hunter. With the help of footprints it can be found on the sand. Peculiarity nervous system in individuals it is very developed. Their memory is good, and they easily remember the paths along which animals walk. They travel long distances in search of food.
The power of crocodiles' teeth
Reptiles have very strong bite. They need a powerful mouth in order to catch and chew turtles and other mammals that have a strong shell. Its bite force is similar to that of a large car. Even a bite from an old animal can be powerful and dangerous. Many people wonder how many teeth a crocodile has? A crocodile has about 60-80 teeth. It all depends on the species. One tooth consists of several parts: a formed fang, an underdeveloped tooth and tissue that consists of a set of stem cells. Scientists carried out an experiment and saw that when a mature fang was removed, a replacement took place, and the underdeveloped element began to actively develop, the tissue grew and after a short time, a new tooth appeared to replace the old one. This one unique method helps the crocodile change teeth more than 50 times. In structure, the teeth of a predator resemble human teeth. But for us, stem cells, once turned on, can no longer work. And the peculiarity of crocodiles is that their teeth are constantly renewed during life. The crocodile tongue grows onto the lower jaw and many people think that they do not have one.
Crocodile weight
An interesting question: how much does a crocodile weigh? The weight of these reptiles depends on the species and age of the individual. They can grow up to 8-9 meters in length and weigh up to 1 ton. The average weight can be about 500 kilograms. Length up to 6 meters. Crested individuals are considered the largest in the world. They live in Asia, in the Philippines. They feed on fish, crayfish, and can attack large cattle, monkeys, pigs. They often attack people underwater in search of food. The next largest is considered the Nile crocodile. He lives in the swamps of Africa. Adults grow up to 5 meters and weigh up to 500 kg. Females are slightly smaller. Despite the presence of short legs in all species, crocodiles are excellent at catching up with prey even on the shore. With the help of their legs, they can run at a speed of 16 km per hour.
Birds-helpers of crocodiles in cartoons and nature: names, videos.
For small children who do not like to brush their teeth, it will be useful to watch a cartoon about a dirty crocodile and a brave bird. We will tell you what its name is and whether its analogue exists in nature in this article.
Which bird brushes the crocodile's teeth in the cartoon: name
- The Soviet cartoon directed by Gennady Sokolsky was named after the tiny fearless bird Tari.
- She was the only one in all of Africa who was not afraid to climb into the mouth of a harmful and evil crocodile. He had big teeth, which he never cleaned. This caused them to get sick. All the animals laughed at the reptile and did not want to help him. Only tiny Tari took on the painstaking and unsafe work. She freed the “scarecrow’s” mouth from debris and pulled out a troublesome tooth.
Tari bird brushes a crocodile's teeth: video
Who brushes a crocodile's teeth in the wild?
Video: Birds Cleaning Crocodile's Mouth
A bird helping a crocodile in nature: name, photo (Wikipedia)
Analogue of the Tari bird in nature - The subfamily of runners of the family Tirkushidae of the order Charadriiformes contains a bird called the crocodile watchman or Egyptian runner (in Latin, Pluvianus aegyptius).
- According to very ancient legend- this bird cleans the crocodile’s mouth from food debris and notifies them of a threat to life. The legend has not been documented. In fact, reptiles don't need to brush their teeth. Lying on the shore with their open mouths, they catch flies.
Crocodiles occupy special position among modern reptiles, being closer relatives of extinct dinosaurs, which survived by almost 60 million years, and modern birds than other reptiles of our time. A number of features of the organization of crocodiles, and first of all the perfection of the nervous, circulatory and respiratory systems, allows us to consider them the most highly organized of all living reptiles. The evolution of crocodiles, starting with the appearance of this group about 150 million years ago, went in the direction of increasing adaptation to the aquatic lifestyle and predation. The fact that crocodiles have survived to this day is often explained by their life in various fresh water bodies of the tropical and subtropical zones, that is, in places where conditions have changed little since the appearance of crocodiles.
The general body shape of a crocodile is lizard-shaped. They are characterized by a long, laterally compressed, high tail, membranes between the toes hind limbs, long muzzle and head flattened in the dorso-ventral direction. The forelimbs have five fingers, the hind limbs have four (there is no little finger). The nostrils, located at the front end of the muzzle, and the eyes are raised and located on the upper side of the head, which allows crocodiles to stay in the water near its surface, exposing only the eyes and nostrils to the air. The external auditory openings are closed with movable valves that protect the eardrums from mechanical damage when immersed in water.
The body, tail and limbs of crocodiles are covered with large, regular-shaped horny scutes located on the back and stomach in regular rows. The dorsal scutes bear longitudinal ridges. In inner layer skin (corium) under the horny scutes of the outer layer on the back and in some species on the belly, bone plates (osteoderms) develop, firmly connected to the horny scutes, forming a shell that well protects the crocodile’s body; on the head, the osteodermis fuses with the bones of the skull.
IN deep layer skin on bottom surface head, inward from the branches of the lower jaw, as well as on the sides of the cloaca there are paired large glands, secreting a brownish secretion with strong odor musk. The secretion of musk glands is especially intense during the breeding season and probably serves animals of different sexes to find each other.
Scull crocodiles has two temporal arches (diapsid): the upper one, formed by the postorbital and squamosal bones, and the lower one, consisting of the jugal and quadratojugal bones. These temporal arches limit the superior and lateral temporal fossae, respectively, at the edges of which they begin masticatory muscles. Extinct dinosaurs, winged lizards, modern fish (hatteria) had a similar structure of the skull, and the skulls of birds, lizards and snakes come from this type of skull.
Characteristic of the skull of crocodiles is the development of a secondary palate - an additional bone “bridge” under the primary palate, separating the nasopharyngeal passage from oral cavity. The secondary palate in modern crocodiles is formed by fusion along midline palatine processes of the premaxillary, maxillary, palatine and pterygoid bones. Secondary internal nostrils - choanas - are located far behind the external nostrils under occipital region skulls The secondary palate is huge functional value for an air-breathing aquatic predator, allowing it to keep its mouth open underwater while continuing to breathe through its nostrils exposed above the water. The entrance to the pharynx is closed in front of the choanae by a palatine curtain, tightly pressed against the arched ridge on the posterior edge of the tongue, in which the anterior edge of the hyoid apparatus lies. The elongated jaws of crocodiles can be compared to tweezers, making it easier to grasp small and mobile prey. Gharials, narrow-snouted crocodiles and other species that feed on fish have the longest jaws.
The quadrate and articular bones of the skull of crocodiles are penetrated by air-bearing outgrowths of the middle ear cavity. Most of the posterior bones of the skull contain cavities of a very overgrown and complex branching system eustachian tubes. Perhaps this entire system of passages and cavities associated with the middle ear and pharynx serves to equalize the pressure in the middle ear when immersed in water.
Teeth crocodiles have a simple conical shape, sit on the premaxillary, maxillary and dentary bones. They are fixed in separate cells (thecodont), which allows crocodiles to have huge “fangs”, up to 5 cm long. The bases of the teeth are hollow inside; new, replacement teeth develop in these cavities. There are multiple changes of teeth during the life of a crocodile. The largest teeth are located at the tops of the convex arches of the scalloped lateral edge of the jaws, and the teeth of the upper and lower jaws are so combined that the largest teeth of the lower jaw are opposed by the smallest teeth of the upper jaw, and vice versa. This allows the crocodile to more reliably hold prey captured in its jaws.
Spinal column crocodiles consists of 9 cervical, 15-16 trunk, 2 sacral and about 40 caudal vertebrae. The vertebral bodies are concave in front and convex in back. The 2-5 posterior trunk vertebrae do not have ribs and are sometimes considered lumbar region spine. 6-8 trunk ribs articulate with the sternum - an oval cartilaginous plate bifurcated at the back. The belly of crocodiles is protected by 7-8 pairs of abdominal ribs, not connected to the spine and located between the sternum and pelvis.
Crocodiles do not have collarbones and shoulder girdle consists of a scapula, a coracoid and an interclavicle that connects below the left and right halves of the girdle (together with the cartilaginous sternum).
IN pelvic girdle The pubic bone does not enter the acetabulum and in its place is the anterior process of the ischium. In the skeleton of the forelimb there is a remarkable elongation of two proximal bones brushes forming additional department limbs.
In the brain of crocodiles the cerebellum is highly developed, which indicates high degree coordination of movements. The sense organs are very perfect. The retina of the eyes consists mainly of rods, the pupil is in the form of a vertical slit that can expand greatly. Inner ear has a well-developed cochlea.
IN oral cavity no salivary glands.
Stomach has thick muscle walls, and adult crocodiles almost always contain a more or less significant amount of stones in it. The weight of stones in the stomach of Nile crocodiles reaches 5 kg (1% of body weight). The role of these stones is not entirely clear; suggest that they increase the specific gravity of the crocodile or. more likely, they move the animal’s center of gravity forward and downward, giving greater stability when swimming.
Circulatory system crocodiles is the most perfect among reptiles, it is characterized by complete separation of the left and right ventricles of the heart. But at the same time, crocodiles retain both aortic arches. The right aortic arch passes into the dorsal aorta, which carries arterial blood to the head, body muscles and all organs that need especially oxygen-rich blood. The left arch of the aorta passes into the celiac artery, which supplies blood to the intestines. At the intersection of two aortic arches, there is an anastomosis between them (foramen of Panizzia), through which, due to the difference blood pressure in arcs arterial blood comes from right arch to the left. When a crocodile breathes atmospheric air, venous blood from the right ventricle apparently enters only into pulmonary artery. When a crocodile dives, resistance to blood flow increases in the vessels of the pulmonary circle, as a result of which venous blood from the right ventricle begins to flow into the left aortic arch.
Lungs crocodiles have complex structure and are capable of holding a large supply of air.
Bladder no, which may be due to life in water. The cloaca has the form of a longitudinal slit, in the rear part of which in males there is an unpaired genital organ equipped with a deep longitudinal groove.
Modern crocodiles inhabit various fresh water bodies. Relatively few species tolerate brackish water and are found in river estuaries (African narrow-snouted crocodile, Nile crocodile, American sharp-snouted crocodile). Only the saltwater crocodile swims far into the open sea and has been observed at a distance of 600 km from the nearest shore.
Crocodiles spend most of the day in the water. They go out to the coastal shallows in the morning and in the late afternoon to warm up in sun rays. The most favorable body temperature for life in Mississippi alligators is 32-35°; Temperatures above 38° are lethal for this species. The lower threshold of activity is about 20°. On land, crocodiles often lie with their mouths wide open, which is apparently associated with thermoregulation: some heat loss occurs when water evaporates from the mucous membranes of the oral cavity.
Crocodiles hunt at night. Fish is an essential component of the diet of all crocodiles, but crocodiles eat any prey they can handle. Therefore, the set of foods changes with age: various invertebrates - insects, crustaceans, mollusks, worms - serve as food for the young; larger animals hunt fish, amphibians, reptiles and aquatic birds. Adult crocodiles are able to cope with large mammals. There is a known case of the remains of a rhinoceros being found in the stomach of a Nile crocodile. Many species of crocodiles exhibit cannibalism - the devouring of smaller individuals by larger individuals. Crocodiles often eat carrion; some species hide the uneaten remains of their prey under an overhanging bank and later devour them half-decomposed.
Crocodiles move in the water with the help of their tail. On land, crocodiles are slow and clumsy, but sometimes make significant journeys, moving several kilometers away from bodies of water. When moving quickly, crocodiles place their legs under their body (usually they are widely spaced), which rises high above the ground. Young Nile crocodiles can gallop at a speed of about 12 km per hour.
Crocodiles lay eggs the size of chicken or goose eggs, covered with a calcareous shell. Number of eggs in clutch different types there are from 10 to 100. Some species bury their eggs in the sand, others lay them in nests made by the female from rotting vegetation. The female remains close to the clutch, protecting it from enemies. Young crocodiles, still inside the eggs, make croaking sounds at the time of hatching, after which the mother digs up the clutch, helping the offspring get out.
Crocodiles grow rapidly in the first 2-3 years of life, during which they reach sizes of 1 - 1.5 m. With age, the growth rate drops, and they gain only a few centimeters in length per year.
They reach sexual maturity at the age of 8-10 years. Crocodiles live up to 80 - 100 years.
Adult crocodiles have few enemies, if you exclude humans. There have been cases of attacks by elephants and lions on crocodiles traveling overland from one body of water to another. In addition, many animals, especially monitor lizards, some turtles, birds (marabou), hyenas, eat the eggs of young crocodiles.
Crocodiles in varying degrees dangerous to humans. Some never attack humans (small blunt-snouted crocodiles, fish-eating narrow-snouted crocodiles, etc.), others attack systematically (salted crocodile), and still others (Nile crocodile) are dangerous only in some areas.
People everywhere exterminate crocodiles, mainly for their skin. In the United States, the extermination of Mississippi alligators has reached such proportions (up to 50,000 alligators are killed per year) that the government has taken special measures to protect these animals, as they are threatened with complete destruction. In some countries of Indochina, crocodile meat is used for food.
There are 21 known species of modern crocodiles (with subspecies number modern forms reaches 28), which are grouped into 3 families.
Animal life: in 6 volumes. - M.: Enlightenment. Edited by professors N.A. Gladkov, A.V. Mikheev. 1970 .
