The animal kingdom consists of millions of organisms, which live on the globe, and differ among themselves in the composition, shape and size. They may be so small that they can only be seen through a microscope, or large. Their lengths may not exceed a few millimeters, or up to more than thirty meters. Some of them live in the highest peaks of the mountains, or in the depths of the sea, both in very cold areas, such as the north and south poles, or very hot, such as the deserts and the equator. Animals of all shapes and sizes live throughout the world. Some of them walk or crawl on the ground, and some of them fly in the air or swim in the water.
The Greek philosopher Aristotle (384 – 322 BC) was the first to collect information on the animals of his time and form, and did not propose an official division of animals more than to divide them into animals with blood, and blood without. But he laid the foundations for this division in a paragraph in which he said: “Animals can be distinguished according to their way of life, actions, habits and body composition.” Aristotle’s attempt was followed by several attempts, until the natural history scientist, Swedish origin, Carolus Linnaeus (1707–1778) came Carolus Linnaeus, and he is rightly called the “imam of modern taxonomy”. He has an important author in this regard, entitled “Natural order” (1758) Systema Naturae, is the basis of modern taxonomy. Modern classification depends on the internal and external structure of the organism, as well as the facts of physiology, ecology, genetics, and embryology.
The American scientist Robert H. Whitaker, R.H. Whittaker, in the 1950s, classified neighborhoods in five kingdoms (major groups):
1-Kingdom of the Protozoan (Monera): Unicellular and composed of primary cells, the nucleus without a membrane (primitive), sometimes groups are formed in the form of chains or other structures.
2-The Protista Kingdom: is a single-celled Protista consisting of eukaryotic cells, large in size, forming groups in the form of chains or colonies.
3-The kingdom of multicellular“Fungi”: filamentous, and specialized cells with complex structure.
4-Plantae Kingdom: Many cells and cells with a complex structure
5-Animalia: Many cells and cells with a complex structure
Taxonomy, a Greek derivative, is composed of two words: Taxis, which means order, and Nomos, which means law. It is a science concerned with the order of the different organisms on a class basis. Each one or more lower groups merge into one group from the top level, whose groups also merge in the same way at the level above and so on. This stratification starts from the basic taxonomic units at the base – the species – going up to the top, expressed in the name of the world or the Kingdom. According to this sequence, there are seven basic classes or ranks: Species, Genus, Family Family, Order, Class, Phylum, Kingdom. The relative position of each animal in the Kingdom can be determined according to this class system, with a moderate accuracy.
With scientific advances and recent discoveries in genetics, the need for more precise regulation emerged. This was achieved through the introduction of additional salaries, among the seven base salaries mentioned above. Thus, there are “superorder” and “suborder” or “suborder” and “superclass” and “subclass” or “subclass”. The term “tribe” was also used between sex and family.
With the dramatic advances in biochemistry and molecular biology, more subdivisions are urgently needed. Generally, the salaries currently recognized are:
Division, Class, Subcategory, Tribe, Sex, Genius, Gender, Type.
In the tenth edition of The Natural System, Linnaeus applied the two-naming system for the first time in a fixed manner to animals. According to this system, the animal became known as the genus, and the species Species, for example, the lion and the tiger of the same family Felidae, and one species called the genus Panthera, but the lion is called Panthera leo, while the tiger is called Panthera tigris.
The taxonomists divided the animal kingdom into two main sections:
Protozoa or Subkingdom Protozoa protozoa, featuring single-celled animals.
Howl Metazoa or Multking Cells Subkingdom Metazoa. This family includes several divisions, the most important of which are: Phylum Chordata, one of the largest and most important divisions of the animal kingdom.In turn, it includes four bronchi, the most important of which is the vertebrate subphylum Vertebrata, whose bodies are characterized by the presence of a spinal cord, extending forward until the middle of the brain. The vertebrates have two main branches:
a. Vertebrates are jawless, have no double limbs, and have a single olfactory organ.
B. Vertebrates with active jaws, olfactory organs, and double limbs. The last group includes five denominations:
- Fish Class Pisces.
- Class Amphibia
- Class Aves.
- Class Mammalia.
The last three denominations, with their different characteristics and special features, are combined by the fact that their embryos are surrounded by a special membrane called the “Amnion membrane”, which is filled with a special fluid called “Amniotic Fluid” to protect the fetus, from the trauma that may be experienced during the formation period. In addition to this membrane, the embryos of this group are surrounded by another external membrane, called the “Allantois”, which consists of the posterior wall of the fetal gastrointestinal tract. The part of the membrane, which is located outside the body of the fetus, is thrown during birth as it is not needed, while the urinary bladder consists of the other part of this membrane, which is located inside the body of the fetus.
The animals of this group are characterized by a neck, not found in the range of fish or amphibians. The neck has a number of cervical vertebrae and has twelve pairs of cerebral nerves, while fish and amphibians have only 10 pairs. The mouth in this group is either fully or partially divided into an upper air passage and a lower food passage.
Class Aves are warm-blooded vertebrates, most of which adapt to live in the air. Their bodies are covered by feathers, varying in density and color. The forward sides have mutated into two wings that help fly, each with three fingers.
The wings move with the help of a number of strong pectoral muscles. The hind limbs, on which the bird moves on the ground, are attached to the body in a relatively forward area, compared to other animals, to help maintain the balance of the bird as it walks on the ground.
God has made these birds special features, help them to fly lightly and gracefully. For example, it has been shown that its bones have air spaces to reduce the weight of a bird flying in the air in defiance of the laws of gravity. They also have air bags attached to the respiratory system, filled with air during flight to help the bird fly. The birds have 14 cervical vertebrae, 5 thoracic vertebrae, three of which are fused together, 6 lumbar vertebrae fuse at the front with the last thoracic vertebra, at the back with the anterior sacral vertebrae, and the first five vertebrae.
The birds of our world today have no teeth, and the front of their skull has mutated into a beak, covered from the outside by a solid horn. The range of birds is divided into two groups, which fall under one of the ranks of birds whose feathers are equipped with fine hooks, such as hawks, chickens, pigeons, parrots, owls and others.
Class Mammalia includes high-end animals, the most advanced. The word Mammalia is derived from the Latin word Mammae, which means “breast.” Therefore, this group is characterized by breastfeeding its young. Mammals have the other characteristic that their bodies are covered with hair, and this characteristic distinguishes them alone without any other type of vertebrates. Even whales and dolphins, water mammals with almost no hair on their bodies, have some hairs that cover the area of the snout.
Like warm birds, mammals are warm-blooded vertebrates and their body temperature is slightly higher than that of the surrounding environment. All of these animals have a couple of limbs, except for some aquatic mammals whose hind limbs have disappeared completely or have left little traces of their presence barely visible outside the body. In some mammals, such as bats, the anterior limbs have mutated into wings, but are quite different in their anatomical structure from those of birds.
There are three groups of animals under this category:
(1) Eggs or monotremata, which multiply by laying eggs, but breastfeed their young and have a beak-like duckbill as in the platypus, or pointy and long as in the eater spinal. The male animals have toxic glands at their back thigh and their droppings come out through a fork.
(2) cysts or mammals dimensional Marsupialia: In this group is born young in the stage of the early embryo somewhat and protected by her mother in a bag in the abdomen topped by a set of nipples to feed the young. Cysts are also monoclonal, including kangaroo and opossum.
(3) Placenta or mammals inherent Eutheria: The most important characteristics of this group is the presence of a placenta through which the embryos feed into the uterus, until the breed is fully developed. This category includes 9 ranks:
Primitive mammals, clawed limbs with a long snout, and large, sharp teeth to suit their nourishing nature, such as the hedgehog and the mole.
2/Order of Chiroptera:
They include flying mammals, such as the fruit-eating bat and the insect-eating bat. It differs from the first type by having a radar-like device that helps it locate the prey.
3/ Order of primates:
The animals of this order are characterized by the large size of the brain and the complexity of its anatomical structure, and holding hands in the front ends, with a thumb in the opposite direction of the moving fingers. These ranks include monkeys, baboons, auspices, sponges, chimpanzees, and orangutan orangutan orangutan: a beating of the great ape-like human Orangutan, and gorillas.
4/Order of Carnivora:
They are mammals that feed on meat, and have strong claws torn by prey, sharp teeth. And it has three cutouts in each decoder. The front and back ends are equipped with at least four fingers and have either retractable or non-moving retractable claws.
The animals in this category include terrestrial carnivores, such as the family of lion cats, Albrber, American seven, tiger, leopard, and the family of bears, which are animals with thick fur and short tail and walk on the belly of the foot and feed on meat, including several types, and the family of dogs with fixed claws , Such as dogs, wolves, and foxes.
5/Order of cetaceans or aquatic mammals
It has no rear ends, and its front ends have evolved into paddles. It also has a dorsal fin, and a tail fin perpendicular to it. The cervical vertebrae in these animals are all fused. They have no nails, skin glands, or outer ears. Under this rank are whales and dolphins.
6/Order of Sirenia:
They are also mammals, but they differ from the previous group by not joining their cervical vertebrae such as sea brides.
They are small mammals, chiseled rodent teeth that grow throughout life, have no canines, and there is a free space between incisors and molars. It falls under this rank: rabbits, mountain rabbits, mice, and crabs.
8/ Toothless Order
The animals of this order lack teeth, with a long, sticky tongue used to catch insects, and have long, strong, sharp claws with curved edges. Members of this rank include: lazy anteater, armadillo armadillo.
Herbivores are herbivores, and are divided into two basic orders:
A/Suborder Ungulata Vera, which is no more than four fingers, include:
Individual fingers Perissodactyla, animals are the third finger in the front and back of the larger than the rest of the fingers, which are much smaller size. The ends end with a hard horn cover, known as the hoof. These animals have a simple stomach. This group represents three families: the family of horses or horses, and the family of rhinoceros or rhinoceros, which is characterized by thick skin and horn or two horns of horny material above the nostril, and the family of tapir, in which the elongated rectangular giving shape hose.
Double fingers Artiodactyla in which the third and fourth fingers are identical in both the front and rear ends, while the rest of the fingers disappear or diminish significantly. The equipment of these animals is complex. This group includes hoof cleft animals, including ruminants from the Camel and Lama family, which are characterized by the presence of teeth in the upper jaw, the elk family, and the bovine family, in which the front teeth in the upper jaw were replaced by a fleshy pillow, and non-ruminant cleft hoof animals, such as pig families and hippos the river.
B/Suborder Subungulata It may have five fingers,
including the rank of Hyracoidea, and Proboscidea like an elephant.