The classification of animals is highly important for understanding the interaction mechanism among animal organisms, as they are complex, multicellular, heterotrophic organisms that cannot produce their food. Therefore, they are classified based on shared characteristics among them.
Below, we discuss the TekeTrek Website More about the methods of animal classification and the mechanism of subclassification in each method.
Scientific Classification of Animals
Animals are classified according to the principle established by Carl Linnaeus, a Swedish botanist, whereby they are grouped based on shared characteristics among them.
The larger the number of features that unite a particular group, the more precise the classification process becomes, relying on a hierarchical sequence from top to bottom as follows:
Kingdom, Phylum, Class, Order, Family, Genus, Species.
The animal kingdom is one of the six kingdoms of living organisms, including animals, plants, bacteria, fungi, protists, and archaea. Each kingdom is divided into what is known as phyla.
Phylum
Animals are divided into seven phyla as follows:
1. Porifera: A marine type called sponges inhabiting the oceans.
2. Cnidaria: A marine type comprising over eleven species including coral and jellyfish.
3. Platyhelminthes: They lack a respiratory or circulatory system, with oxygen distributed throughout their bodies via diffusion, including flatworms and tapeworms.
4. Annelida: Segmented worms with a nervous system and respiratory system, including earthworms and leeches.
5. Mollusca: Considered the largest marine phylum and the second largest in species diversity. It includes creatures such as clams, mussels, and snails.
6. Arthropoda: Invertebrates with an external skeleton and segmented bodies, including insects, crustaceans, and spiders, occupying the first position in terms of species diversity.
7. Chordata: Have a vertebral structure supporting their bodies, which then develops into a spinal column, including animals such as dogs, horses, and birds.
Each phylum is then divided into smaller groups called classes.
Animal Classification
Class is a smaller group within a phylum, where the phylum Chordata is divided into several classes, including:
1. Fish: They inhabit large bodies of water such as freshwater, saltwater, and slightly brackish. Examples include:
– Chondrichthyes: Fish with cartilaginous skeletons, divided into two classes:
– Elasmobranchii, including rays, skates, sawfish, and sharks.
– Osteichthyes, including bony fish found in both saltwater and freshwater, such as eels, barracudas, herrings, swordfish, salmon, carp, and trout.
2. Amphibians: Vertebrates with external limbs, such as frogs and salamanders.
3. Reptiles: Their skin is dry and includes snakes, turtles, lizards, and crocodiles.
4. Birds: Warm-blooded vertebrates that lay eggs and are characterized by wings and feathers.
5. Mammals: Warm-blooded animals with four limbs, two of which are arms and the other two are legs, reproducing through live birth.
Then, each class is divided into smaller groups called orders.
Order
Order is a sub-classification within the class in animal classifications. For example, mammals include the following orders:
– Ungulates: Such as camels and giraffes.
– Carnivores: Feeding on meat, possessing non-retractable claws and a long snout like bears.
– Rodents: Including rats, mice, and squirrels.
– Bats: The only mammals capable of flight, such as vampire bats.
– Cetaceans: Including killer whales and dolphins.
Linnaeus classified animal orders into smaller groups called families.
Family
Family is a sub-group of the order class, divided into two main groups: vertebrates and invertebrates. Some notable vertebrate families include:
– Felidae: Such as cats.
– Canidae: Such as dogs and wolves.
– Ursidae: Such as bears.
– Mustelidae: Such as badgers and weasels.
– Mephitidae: Such as skunks and the hyena.
– Herpestidae: Such as mongooses.
– Canidae: Such as foxes.
– Otariidae: Such as sea lions and fur seals.
Then, each family is divided into smaller groups called genera.
Genus
The genus is a subclassification within the family in animal classifications, encompassing several animals with similar traits. For example, within the Felidae family:
– Felis includes domestic cats.
– Panthera includes tigers, lions, and leopards.
– Smilodon includes saber-toothed cats (this genus is extinct).
– Caracal includes African golden cats.
Animal Classification According to Diet
Animals are classified based on their dietary sources into three categories: carnivores, herbivores, and omnivores.
Carnivorous Animals
They primarily rely on meat in their diet, obtaining it through hunting other animals or scavenging carcasses. They are characterized by:
– Having strong jaws, sharp cutting teeth, and large used for meat tearing.
– Some have strong, hooked beaks with sharp claws.
– Some have a short digestive tract that does not hinder the digestion of plant material.
Examples include lions, crocodiles, and snakes.
Herbivorous Animals
They rely on plants for their diet, such as elephants, camels, giraffes, and deer. They are characterized by:
– Having broad, flat molars that help grind leaves and grass.
– Some, like sheep and deer, have a stomach divided into four chambers that assist in efficient digestion.
Omnivorous Animals
They rely on a variety of foods such as plants, meat, algae, and fungi. Examples include bears, red foxes, and raccoons. They are characterized by:
– Having some characteristics of carnivorous animals and some characteristics of herbivorous animals. For example, sharp front teeth aid in tearing meat, while large molars assist in chewing plants.
– They are not affected by the disappearance of one food source, thus having a greater chance of survival.
– They can easily adapt to new environments in case their original habitat is destroyed.
Animal Classification According to Habitat
Animals can be classified according to their habitat into five types:
1. Wild animals: Living on land, having four legs, such as tigers, lions, and elephants.
2. Aquatic Animals: Living in water, such as fish, characterized by specialized respiratory organs known as gills.
3. Aerial Animals: Spend most of their time in the air, such as birds.
4. Arboreal Animals: Found on trees, such as monkeys, squirrels, and chameleons.
5. Amphibious Animals: Living in both water and land, with cold-blooded characteristics, possessing a slimy and permeable skin allowing the passage of both water and air, including frogs, salamanders, and caecilians.
Animal Classification According to Reproduction Method
Animals can be classified according to their reproductive method into two main types:
1. Mammals: Reproducing through live birth and giving birth to offspring.
2. Non-mammals: Reproducing through laying eggs.
Frequently Asked Questions
– How are animals classified?
Animals are classified into several groups based on shared characteristics, with each group having a set of unique traits that differentiate it from other groups.
– How many species of animals are there in the world?
There are over 1.5 million species of animals.
– How are invertebrate animals classified?
Invertebrate animals are classified according to shared characteristics, including Porifera, cnidarians, annelids, mollusks, arthropods, and echinoderms.
– How are vertebrate animals classified?
Vertebrates have a vertebral column and include fish, amphibians, reptiles, birds,
and mammals.
In summary, animals can be classified in several ways, based on the characteristics that distinguish each group from others. For example, based on their dietary source, habitat, or reproductive method.
