Animals and Their Classification
Welcome to the "Animals" section of our site! Here, we celebrate the wildlife that roams our planet. Whether you're a seasoned wildlife enthusiast or just curious, you'll love this.
This is not designed to be some kind of long-winded encyclopedia. Yes, one of the goals is to be more knowledgeable about animals, but also, we give practical information and useful tips on how to spot and observe these wonderful creatures.
If like me you’re a nature lover, you know how thrilling it feels to encounter the majestic, awe-inspiring, sometimes strange species that call Earth home. Our goal with this new section is to spark your curiosity and, who knows, ignite your passion for the animal kingdom and encourage you to get out there, and include wildlife watching in your trips. Promoting responsible and sustainable wildlife tourism is one of our core values.
Here, we are all about exploring the incredible diversity of the Animal Kingdom. Because, let’s face it, we are all able to give a sizeable list of animals that we know, but there are so many creatures out there that most of use have never heard of!
So let’s jump in and learn more about them!
115 Incredible Animal Facts
Be amazed by the mysteries of the Animal Kingdom with these 115 animal facts that will blow your mind!
Classification of Animals
Our planet hosts a breathtaking array of animal species, believed to number in the millions.
In order to facilitate research and understand the connections among them, scientists have arranged these species into various classifications.
Taxonomy, the scientific method of grouping living organisms based on their shared traits into categories known as ‘taxa’ (the plural of ‘taxon’), plays a crucial role in this process.
The hierarchy of classification comprises eight main levels:
Given the intricacies of life on Earth, additional levels such as superclasses, suborders, or subspecies are sometimes needed and incorporated.
Carl Linnaeus, an 18th-century Swedish botanist, is credited with the development of this system, hence it’s referred to as Linnean Taxonomy.
Take, for instance, the full taxonomic classification for a lion:
- Domain: Eukaryota
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Carnivora
- Suborder: Feliformia
- Family: Felidae
- Subfamily: Pantherinae
- Genus: Panthera
- Species: leo
Linnaeus also introduced the binomial nomenclature, a method of naming organisms using their Genus and species names. So, a lion is scientifically known as Panthera leo. As a standard practice, these Latin names are italicized.
The use of Latin, an extinct language, ensures that scientific names of species will remain consistent as the language won’t evolve further.
Vertebrates & Invertebrates
Animals are primarily divided into two broad categories. Vertebrates have a spine or backbone, while invertebrates lack one.
Vertebrates belong to the phylum Chordata and are further subdivided into seven classes, accommodating both warm and cold-blooded species:
- class Mammalia – Mammals
- class Aves – Birds
- class Agnatha – Jawless fish
- class Chondrichthyes – Cartilaginous fish
- class Osteichthyes – Bony fish
- class Reptilia – Reptiles
- class Amphibia – Amphibians
In contrast, invertebrates are grouped into several phyla, including:
- phylum Porifera – Poriferans
- phylum Echinodermata – Echinoderms
- phylum Cnidaria – Cnidarians
- phylum Mollusca – Mollusks
- phylum Annelida – Annelids or segmented worms
- phylum Platyhelminthes – Flatworms
- phylum Nematoda – Nematodes or roundworms
- phylum Arthropoda – Arthropods, which is further divided into subphyla and classes such as Arachnida, Crustacea, Insecta, and Myriapoda.
Types of Animals
Let's now take a closer look at the different groups of the Animal Kingdom.
Belonging to the class Mammalia, mammals are warm-blooded vertebrates notable for their ability to nourish their offspring with milk produced by mammary glands.
This class includes a large number of familiar animals.
Representing the class Aves, birds are also warm-blooded vertebrates.
They are distinctively characterized by feathers, beaks, and egg-laying reproduction, among others.
The category of fish is actually divided into three groups: jawless fish, cartilaginous fish, and bony fish.
All types of fish are aquatic, rely on gills for respiration, and are cold-blooded.
Reptiles, cold-blooded creatures belonging to the class Reptilia, are recognized by their scaly skin.
The reptile group includes animals with four legs like turtles and crocodiles, as well as limbless species such as snakes.
Amphibians are vertebrates from the class Amphibia.
Cold-blooded by nature, their name refers to their dual life— both in water and on land. Indeed, many amphibians begin their life as aquatic larvae before moving to a more terrestrial lifstyle.
Mollusks, or Molluscs, come under the phylum Mollusca and represent the second-largest invertebrate group after Arthropods. Nearly a quarter of marine species fall under this group, with many species possessing a calcareous shell.
Insects, invertebrates falling under the Arthropod class, are characterized by an exoskeleton rather than a backbone.
They are recognized by their tripartite body structure comprising the head, thorax, and abdomen, as well as their six legs.
Arachnids form another class within Arthropods, which includes creatures like spiders and scorpions.
These invertebrates, known for their eight legs, have a body divided into two sections: the cephalothorax and the abdomen. Unlike insects, they lack wings and antennae.
Crustaceans are another type of invertebrate, specifically from the class Crustacea within the Arthropod phylum.
Examples of crustaceans include crabs, lobsters, and shrimp. Their bodies are composed of a head, a thorax (sometimes merged), and an abdomen, all covered by an exoskeleton.
Myriapods belong to the Myriapoda class under the Arthropod phylum.
This group of invertebrates, which includes millipedes and centipedes, are all terrestrial creatures. Their name, derived from Greek, implies “ten thousand feet.”
The Cnidaria phylum consists of mostly marine invertebrates, with well-known members like jellyfish, sea anemones, and corals.
They possess tentacles equipped with specialized cells, cnidocysts, used to capture prey — this is what stings when a jellyfish touches you.
Echinoderms, from the phylum Echinodermata, are marine organisms with an ossified skeleton. Species such as sea urchins, starfish, brittle stars, sea cucumbers, and crinoids all belong to this category.
Members of the Porifera phylum, often known as sea sponges, are simple invertebrates lacking organized tissues and organs.
The name Porifera, meaning “pore-bearer,” aptly describes these creatures, which have many pores that enable water circulation through their bodies.
Annelids, known as segmented worms, are invertebrates from the phylum Annelida. Their bodies consist of a series of repeating segments, each containing similar organs.
This phylum includes familiar creatures such as earthworms and leeches.
Flatworms are from the phylum Platyhelminthes. Unlike annelids, they lack body segments and possess simple biological structures without dedicated circulatory and respiratory systems.
They possess a flat body that facilitates oxygen diffusion and a digestive system with a single opening, functioning both as a mouth and an anus.
Nematodes, also called roundworms, are a part of the phylum Nematoda. They inhabit nearly every ecosystem on Earth, including the human body.
These creatures are small, thin, and sometimes microscopic.
Browse & Discover Animals
Browse our addictive animal lists, filled with interesting and surprising facts about hundreds of animals, along with great pictures. We have organized them in different sections to make everything easier.
Animals by Color
Animals by Physical Feature
- Animals without tails
- Animals with long tails
- Animals with horns
- Animals with hooves
- Animals with antlers
- Animals with opposable thumbs
- Animals with long faces
- Animals with big heads
- Animals with claws
- Animals with flippers
- Animals with small eyes
- Animals with big lips
- Animals with human-like teeth
- Animals with big eyes
- Animals with thick skin
- Animals with fangs
- Animals with more than 2 eyes
- Animals with long tongues
- Animals with short arms
- Animals with long ears
- Animals with bushy tails
- Animals with purple eyes
- Animals with blue or black tongues
Frequently Asked Questions About Animals
Among the 8.7 million various species contributing to the biodiversity of our planet, the estimated count of animal species ranges from one to two million.
In a 2009 study, mathematician and animal rights activist Brian Tomasik estimated the total number of individual animals living on Earth. His computations suggested a figure of 20 quintillion, equivalent to 20 billion billion or 20,000,121,091,000,000,000 animals.
Indeed, humans are classified as animals. We belong to the categories of vertebrates, mammals, and primates, sharing these classifications with creatures like chimpanzees and bonobos, our nearest genetic relatives. Our advanced cognitive abilities often make us perceive ourselves as separate. An insightful article discussing this topic can be found on Science Focus.