What Are the Classification of Animals?

Vertebrate and Invertebrate Animals Classification

In the classification of animals, some animals are widely similar in behaviors, eating habits, features, and habitat choice, while others are poles apart and chose to behave totally differently. The reason for this is simple, as these animals are classified into various categories based on their similarities.

Classification of Animals Chart

Animals are broadly classified into two major groups, including vertebrates and invertebrates. Vertebrates are the ones with a backbone, and Invertebrates are without a backbone. You can see below the animal’s classification chart or diagram to understand the subcategories of both major groups.


They are further explained in full detail below with examples:

Vertebrate Animals Classification

There are 65000 accounted vertebrate species of animals. However, they only constitute 3% of the animal kingdom. Vertebrates are classified into further subgroups, i.e., warm-blooded and cold-blooded.

Let’s look at the warm-blooded vertebrates animals classification first-

Warm-Blooded Vertebrates Classification

Warm-blooded or endothermic animals can adjust their body temperature. Only mammals and birds in the animal classifications are warm-blooded.

Mammals Classification

Mammals are warm-blooded vertebrates with a backbone and full of fur or hair. All mammal infants drink milk. Although whales are an exception, being a mammal, they are born without any hair. There are different classifications of animals in the world, but mammals are the best-known ones.


Let’s look at types of animals in the mammal’s category:

  • African Bush Elephant

The African bush elephant is the largest land animal (approx. 6 tonnes). They restore their teeth almost six times during their lifetime but shed their teeth when they are 40–60 years old, which is also how they die due to starvation. They are native to southern and central Africa and are found in savanna, flood plains, and forests.

  • Polar Bear

The polar bear is the largest living carnivore. They are known for their pure white coat that changes colors to brown and yellow depending on the season. Their fur is water and oil-proof. Polar bears prefer to live in the Arctic Ocean. They can swim for many days and can cover long distances. They feed mainly on seals. Polar bears have a keen sense of smell and are patient hunters.

  • Cougar

Cougars or Pumas are the second-largest cats in North America. This big cat cannot roar but can scream, purr, growl, hiss, chirp, and whistle. Cougars are great hunters and prey on raccoons, deer, and crocodiles. They can jump up to 20 feet into the air and can easily pounce from a standing position. Cougars can adapt to every habitat and can be found in lowland areas, mountainous deserts, and forests.

  • Dolphin

The common dolphin is found in warm seas, mainly the Mediterranean Sea. They travel in groups of 10–50 individuals. They also meet in schools of 100-2000 and are seen jumping, splashing, and surfacing together. Dolphins can accelerate up to 40 km/hr and prey on squid, crab, and fish. Their lifespan is 20–45 years long. Unfortunately, they are attacked by killer whales, sharks, and humans.

  • Eastern Gorilla 

The eastern gorilla is the largest land primate in the world. They are close relatives of humans and are seen peeling several fruits by hand.

There are two types of eastern gorillas: eastern lowland gorillas and eastern mountain gorillas. They live in groups of 35–50 individuals. The eastern gorilla feeds on tree bark, flowers, fungi, wild berries, and small invertebrates.

  • Fin Whale 

The fin whale or razorback is one of the largest animals (approx. 80 tonnes) on earth. They are fast swimmers and are known as the greyhound of the sea. Fin whales travel in pods of up to 10 individuals. They communicate in low-pitched sound (16–40 Hz) with each other. They also produce rumbles and regular pulses at 20 Hz. Fin whales prefer temperate and cool waters.

Many more mammals include elephants, armadillo, giant panda, jaguar, lemur, otter, porcupine, and others.

Mammals live in many habitats such as land, underground, and ocean. Mammals like chimpanzees, dolphins, and elephants are considered intelligent. The next warm-blooded animal is the birds.

Birds Classification


Birds have over 10,000 species and are distinguished by every other animal because of their feathers and beaks. They have four-chambered hearts and are warm-blooded vertebrates. Birds are diurnal and have great vision.

Birds migrate from one habitat to another due to season change. Some examples of birds are given below:

  • Cooper’s Hawk

Cooper’s hawk or striker prefer to live in densely wooded regions of North America and prey on mammals, small birds, and insects. They have short wings (33 inches), camouflaged feathers, and very long tails. Cooper’s hawks are patient hunters and spend more time waiting for their prey. They only make sounds for warning threats.

  • Falcon

Falcon is the fastest animal on earth, both in the air and on land. Their precision and speed let them catch their prey mid-flight. This solitary bird migrates seasonally, evading cold winters but is also territorial when they return to their home. Falcon is carnivorous and feeds on small amphibians, rodents, and reptiles.

There are many more birds such as owls, herons, kingfisher, flamingos, cuckoo, pigeons, stork, and others.

All birds produce eggs; some are spotted while others are colorful. Birds, both male and female, care for their young and help protect them by building nests.

Cold-Blooded Vertebrates Classification

Cold-blooded or ectothermic vertebrates are unable to regulate their body temperature. Their internal temperature is dependent on outside forces. They lay in the sun and under the shade to cool down and warm up.

In this order of animal classification, we have fish, reptiles, and amphibians, which are discussed below:

Fish Classification

There are many different classifications of animal kingdoms globally, with fish being the most diverse, including over 33,000 species. Fish are aquatic vertebrates and are cold-blooded. They are known for their gills that help them breathe underwater.


Fish is also an easily threatened species due to overfishing, changing environment, and pollution. Let us look at some examples and types of fishes in animals classification here:

  • Basking Shark

A basking shark or bone shark is intimidating in appearance and is the second-largest shark species. They frighten swimmers with their massive size. Basking sharks filter ocean water through their largemouth and eat tiny life forms and plankton. They are slow swimmers and generally leave their mouths open. Basking sharks are commonly found in the Atlantic and Pacific oceans.

  • Black Marlin 

Black Marlin is the fastest fish and largest bony fish in the world. Every black marlin is always born as a female. They are generally found in the Pacific and Indian oceans. Black marlin can accelerate up to eighty miles per hour. They prefer shallow waters and remain near coral reefs, continents, and islands. They prey on octopods, cuttlefish, crustaceans, and squid.

  • Eel 

Eel is snake-like fish. Eels have more than 800 species. Electric, muraena, electric, and conger are the most dangerous eel species. Eel fish are found in rivers, oceans, and lakes. They prefer deep underwater and take refuge in muddy waters, coral reefs, and rock fissures. Eels are carnivores and feed on crabs, shrimp, sea urchins, fish, and crustaceans.

  • Immortal Jellyfish 

Immortal jellyfish or Benjamin button jellyfish are immortals, able to regenerate and live forever. However, they can die if they are taken out of the water or acquire some disease, and they can also be eaten. They are commonly found in the Atlantic oceans of Japan, Spain, and Panama. There are no other species of immortal jellyfish. Their body is transparent and bell-shaped, and they feed on plankton.

There are much more fish such as blue tang, stonefish, piranha, rainbow trout, mandarin fish, giant snakehead, and others. Fish comes in all shapes and sizes, and while some are carnivores, others are herbivores, and then some are also omnivores.

Reptiles in Animals Classification

Reptiles are cold-blooded, air-breathing vertebrates with a spinal cord. They are known for their rough, scaly skin. Reptiles are an ancient breed and have more than ten thousand species. This diverse group includes turtles, dinosaurs, snakes, lizards, and crocodiles. Unfortunately, almost 20% of the accounted reptile species can go extinct.


There are different classification of animals in the world, and reptiles are the ones that are present in almost every ecosystem. Some examples of reptiles are given below:

  • Alligator

Alligators or gators are just as large as crocodiles and belong to China and the USA. They have a powerful, versatile tail that is used for both swimming and defense. There are some differences between a crocodile and an alligator, i.e., when the crocodile closes its mouth, its teeth can be seen while the alligators cannot. Their lifespan is 30–60 years long. They live in swamps and marshland.

  • Blue Iguana

Blue Iguana belongs to an endangered lizard species. They are native to Grand Cayman. A mature female iguana can be pale blue to olive green in color, while a male iguana is turquoise to dark grey. This solitary creature is small in size (20–30 inches) and is extremely territorial. They can also climb trees up to 15 feet and higher.

  • Frilled Lizard

A frilled lizard or frilled dragon is popular for lifting its neck frill. It helps to intimidate predators. The frilled lizard is not poisonous and can stand up and run on its hind legs. They live in woodland and tropical forests. This solitary creature prefers trees and easily camouflage due to its gray-brown scales. Their lifespan is 10–20 years long. A frilled dragon is an omnivore.

  • Rattlesnake

Rattlesnakes are poisonous snakes that are known for their rattles located at the rear end of the tail. They have 35 species, Mojave rattlesnake being the most dangerous one. They use their venom to kill their prey. Rattlesnakes are the most evolved snakes and can control their venom use when they bite. They are native to Argentina, Canada, and America.

  • Indian Star Tortoise 

Indian star tortoise is a most striking tortoise with a star-shaped pattern on its shell. They are native to India, Sri Lanka, etc., and are commonly found in grasslands, shrublands, and forests. Star tortoise is made for dry as well as wet habitats. Their lifespan is 30–80 years long. Reptiles, birds, and humans usually attack them. However, the Indian star tortoise is a herbivore.

There are many more reptiles such as chameleon, python, king cobra, box turtle, Malayan gharial, etc.

Reptiles’ layout under sunlight to increase their body temperature. While snakes and lizards smell through their tongues, turtles are born with no ears but have exceptional hearing. The next type of animal is amphibians.

Amphibians in Animals Classification

Amphibians are versatile and cold-blooded vertebrates. They can survive on land and in water. Amphibians have more than 6000 species, 90% of which belong to frogs.


Water commands all amphibians’ lives, although some salamanders can survive on trees. Some examples of amphibians are given below:

  • Glass Frog

Glass frogs are exotic frogs found in Central, South America, and southern Mexico. They are known for sticky-webbed feet and translucent skin. The glass frogs prefer to live in rainforests, high in the trees near a stream. Their lifespan is 14 years long. They have great eyesight and can jump more than 10 feet away from predators. They are nocturnal and preys on small insects and small fish.

  • Olm

Olm or cave salamander or human fish (due to its skin color) is a blind amphibian. They are found in southern European caves, rivers, and lakes. They spend their entire lives in darkness; however, they have an exceptional sense of smell and hearing. Olm is a carnivore and feeds on larvae, snails, aquatic insects, and worms. Their lifespan is 10–50 years long.

There are many more amphibians such as caecilians, hellbender, mountain chicken, gold poison dart frog, Colorado river toad, etc.

Unfortunately, Amphibians are a threatened species of animals, although they are bright-colored that helps them warn predators to keep their distance. The next type of animal is fish.

Invertebrate Classification of Animals

Invertebrates are cold-blooded animals with no spinal column and can live on land as well as water. They are the most diverse species of the animal’s classification.

Invertebrate classification of animals includes Porifera, Platyhelminthes, Cnidaria, Arthropoda (Crustacea, Arachnida, Insects, Myriapoda), Annelida, Echinodermata, and Mollusca.



Porifera are sponges. It’s very diverse with 5000 species. Sponges are mainly marine. Sponges have cellular organization and have canals and pores that help to pass water. They are symmetrical as well asymmetrical. They are found in all water habitats, but they are more diverse and common in a marine environment. Sponges have three body types, including Syconoid (tubular body and a single osculum), Asconoid (simple tube with pores), and leuconoid (Numerous canals and tissues).



Platyhelminthes or flatworms are triploblastic and bilaterally symmetrical. Their bodies are like worms varying from moderately flattened to ribbon and leaf-like. They also vary in size ranging from tiny or microscopic to quite long, around 15 meters. Platyhelminthes body is soft as well because of the absence of endo and exoskeleton. They also lack circulatory and respiratory systems. Their lifespan is complex, and they generally require more than one host.



Cnidaria is mostly marine and has 9000 species. They are radially symmetrical and have two cell-layered bodies. Cnidaria has no internal organs and has two body types, i.e., medusa (jellyfish) and polyp. There are four different kinds of Cnidaria, including hydrozoa (fire corals), cubozoa (box jellies), Scyphozoa (true jellyfish), and Anthozoa (true corals). Examples of Cnidaria are hydras, sea pens, corals, sea fans, etc.

Arthropoda Animals Classification

Anthropods are found in every habitat and are the most successful animal in the world. They have inhabited sea, land, and air and have over a million species. Arthropoda is further classified into four sections, crustacea, Arachnida, insects, and Myriapoda.



Crustacea has over 40000 species and are mostly marine but are found in freshwater as well. Small crustaceans use their bodies for breathing while large crustaceans use their gills. Crustaceans have a hard outer body or exoskeleton that protects them from predators. Examples of Crustacea are shrimps, lobsters, crabs, isopods, prawns, remipedia, and others.


Arachnids have segmented bodies, but they lack jaws. They have a hard exoskeleton and come in many sizes going from .08 mm (tiny mites) to 21 cm (scorpion). Most Arachnids are free-living; however, some are parasitic, like mites and ticks. Most arachnids are solitary creatures and eat anthropods. Examples of Arachnida are a scorpion, tick, garden spider, red-kneed tarantula, and others.


Different classification of animals exists in the world, but insects are found in every environment. Insects outnumber every other animal in the world. They account for over a million species. The queen of termites is known to live for 50 years, making it the longest-living insect. Examples of insects are:

  • Locust 

Locust is known for locust plagues that are caused by their swarming behavior. They attack vegetation, farmland, and crops. Locust is not a particular species. They have brown or green shells. Also, they jump, hop, sing and create sounds from their long back legs. They are found everywhere in the world except in North America and Antarctica. They prefer to live in woodlands and wetlands.

  • Wasp

Wasps are the most diverse insects, with over 100,000 species. Wasps are both solitary and social. Social wasps reside in colonies made up of 10,000 individuals. They make chewed wood nests in meadows, rock faces, and forests. Wasps are omnivores and eat honey, nectar, tree sap, caterpillars, and fruit. They have yellow, black color and can attack their prey repeatedly through their stinger.

There are many more insects such as honey ants, fireflies, leaf beetles, monarch butterflies, carpenter moths, mole crickets, etc.

Insects have exoskeletons that support and protect the body. Insects play an important part in the environment, and they help in the pollination of flowering plants.


Myriapods are terrestrial and have 13000 species. Myriapoda has a long, segmented body and has a tough exoskeleton. Myriapods are important in the ecosystem, they are food for many vertebrates, and invertebrates like centipedes eat insects, and millipedes prey on decaying plant matter and leaf litter.



The annelids consist of leeches, polychaete worms, and earthworms. Annelid is a segmented worm. Annelida are found in every habitat, mainly in damp soil, freshwater, and seawater. They either burrow, stay at the bottom, float, or live-in tubes. Annelida can change colors, and some can even produce their own light. They vary in size ranging from an inch to measuring up to 20 feet. The largest species in Annelida are earthworms and polychaetes.


Sea-urchin in classification of animals

Echinodermata are found in a marine environment and have about 7000 species. They live in shallow waters as well as deep waters of the sea. They are found in every water habitat from saltwater, temperate to polar. Echinoderms have spiny skin and are vulnerable at the larval stage. Echinodermata have a water vascular system. They have canals that help circulate water and aid in nutrition and locomotion. Examples of Echinodermata are sand dollars, sea cucumbers, brittle stars, and sea urchins.



Mollusca or Mollusk is a diverse group with 100000 species. They are mostly marine and are found in other animals as parasites. Their body is unsegmented, triploblastic, soft, and bilaterally symmetrical. They vary in size ranging from little snails to giant squids. Examples of Mollusca are gastropods, Solenogastres, hygrophila, cuttlefish, and Bivalvia.

All animals, be it birds, reptiles, mammals, amphibians, fish, or invertebrates, are essential for the balance of the ecosystem. The most important feature of an animal is its mobility, i.e., the ability to move in search of food. Animals are competitive and adapt and evolve for survival. Animals’ diversity demonstrates their flexibility in reproduction, defense, and feeding.


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