Animal Kingdom Facts and Pictures

Gills are organs that extract oxygen from the water and excrete carbon dioxide. As of May 2023, 70,347 vertebrate species are listed in the Catalogue of Life (an online species database). The mantle covers much of the body and forms a cavity which houses the mollusk’s vital organs. Most mollusks live in the sea, but some, such as snails and slugs, are also found on land.

One of the most distinctive characteristics of mammalia is that female mammals have mammary glands. Mammals have hair, are warm-blooded, breathe air, and all but five species give birth to live young. Last but not least we come to the mammals, members of the class Mammalia. More than half are passerines, or “perching birds”, members of the order Passeriformes. Birds are feathered, egg-laying vertebrates, most of which are able to fly. The first birds evolved from dinosaurs around 150 million years ago, over time losing their teeth and tails and developing beaks.

Diversity

However, several lineages of arthropods begun to colonise land around the same time as land plants, probably between 510 and 471 million years ago, during the Late Cambrian or Early Ordovician. Animals oxidise carbohydrates, lipids, proteins and other biomolecules in cellular respiration, which allows the animal to grow and to sustain basal metabolism and fuel other biological processes such as locomotion. Some consumers use multiple methods; for example, in parasitoid wasps, the larvae feed on the hosts’ living tissues, killing them in the process, but the adults primarily consume nectar from flowers. In carnivorous or omnivorous species, predation is a consumer–resource interaction where the predator feeds on another organism, its prey, who often evolves anti-predator adaptations to avoid being fed upon.

What Is An Animal?

(Some amphibians, such as the axolotl, don’t undergo metamorphosis.) After undergoing a process known as metamorphosis, amphibians develop lungs and are able to live on land. Amphibians have moist skin, and lack the protective scales found in reptiles. Amphibians evolved from fish around 360 million years ago. The skeletons of bony fish are made of bone, whereas those of cartilaginous fish are made of a flexible, bone-like substance called cartilage.

What are the two major groups of animals?

In addition to sponges, Placozoa has no symmetry and was often considered a “missing link” between protists and multicellular animals. Trace fossils such as tracks and burrows found in the Tonian period (from 1 gya) may indicate the presence of triploblastic worm-like animals, roughly as large (about 5 mm wide) and complex as earthworms. The first body fossils of animals appear in the Ediacaran, represented by forms such as Charnia and Spriggina. Several animals are microscopic; some Myxozoa (obligate parasites within the Cnidaria) never grow larger than 20 μm, and one of the smallest species (Myxobolus shekel) is no more than 8.5 μm when fully grown.

Animals: A Complete Guide To The Animal Kingdom

The largest terrestrial animals that ever lived were titanosaur sauropod dinosaurs such as Argentinosaurus, which may have weighed as much as 73 tonnes, and Supersaurus which may have reached 39 metres. Animals occupy virtually all of earth’s habitats and microhabitats, with faunas adapted to salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of other organisms. Herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have eaten the herbivores.

Discover, Appreciate, & Understand the Animal World!

Most have four legs, but some species spend most of their lives in the water and only have two small front limbs. Caecilians are burrowing animals that resemble worms or snakes. Many amphibians begin life in water as larvae equipped with gills. Cartilaginous fish include the sharks, rays and skates. The group includes fish such as trout, goldfish, cod and marlin. Fish are aquatic animals with streamlined bodies, fins instead of limbs, and gills.

• 24-Isopropylcholestane (24-ipc) has been found in rocks from roughly 650 million years ago; it is only produced by sponges and pelagophyte algae.
• Lizards, dinosaurs, crocodiles, turtles, and snakes – all belong to that ancient and stout class of animals known as the reptiles.
• Nearly all modern animal phyla first appeared in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago (Mya), and most classes during the Ordovician radiation 485.4 Mya.
• Amphibians cover over 6,000 different species across the globe, but about 90% are frogs.
• In sponges, blastula larvae swim to a new location, attach to the seabed, and develop into a new sponge.
• What are the 6 types of animals?

Cats are the second most popular pet on earth with nearly 400 million worldwide. Thats almost one dog for every 15 people on earth! Dogs are the most popular type of pet on earth with nearly 500 million worldwide.

Crustaceans

• So integral is movement to the conception of animals that sponges, which lack muscle tissues, were long considered to be plants.
• In contrast, invertebrates lack a backbone and are immensely diverse, making up about 97% of all known animal species.
• The first animals were likely sponge-like sea creatures that appeared in Earth’s oceans around 665 million years ago (source).
• Animals oxidise carbohydrates, lipids, proteins and other biomolecules in cellular respiration, which allows the animal to grow and to sustain basal metabolism and fuel other biological processes such as locomotion.
• They also have a gut that extends through the basically cylindrical body from mouth to anus.

A pet is a domesticated animal that lives with a person or family, usually in a house. See the complete list of insects. All insects are part of the taxonomical phylum Arthropoda, and they are collectively referred to as arthropods.

Thank you for visiting Active Wild!

See the complete list of birds. However, they are more closely related to reptiles and are believed to have evolved from dinosaurs. If you see an animal with feathers, it’s undoubtedly a bird.

Latest Articles from A-Z Animals

This is one of the key ways to know if an animal is a mammal. That’s why we are building the world’s greatest animal encyclopedia, completely free to you. Among other mammals, deer, horses, lions, bats, bears, and wolves are the subjects of myths and worship. Some medicines such as the cancer drug trabectedin are based on toxins or other molecules of animal origin.

Humans make use of many other animal species for food (including meat, eggs, and dairy products), for materials (such as leather, fur, and wool), as pets and as working animals for transportation, and services. We hope that you have enjoyed reading about animals and the animal kingdom. Protected by scales, and able to lay eggs, early reptiles were no longer reliant on water, and could occupy habitats unavailable to amphibians.

Types of Animals By Letter: Explore A to Z Animal Lists

The digestive chamber has two openings, a mouth and an anus, and in the Nephrozoa there is an internal body cavity, a coelom or pseudocoelom. Animals in both phyla have distinct tissues, but these are not organised into discrete organs. However, similar tracks are produced by the giant single-celled protist Gromia sphaerica, so the Tonian trace fossils may not indicate early animal evolution. Animals are thought to have originated under low-oxygen conditions, suggesting that they were capable of living entirely by anaerobic respiration, but as they became specialised for aerobic metabolism they became fully dependent on oxygen in their environments.

Sponges lack the complex organisation found in most other animal phyla; their cells are differentiated, but in most cases not organised into distinct tissues, unlike all other animals. Some benthic animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter produced through chemosynthesis (via oxidising inorganic compounds such as hydrogen sulfide) by archaea and bacteria. Other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. Unlike plants and algae, which produce their own food, animals cannot produce their own food, a feature they share with fungi.

Animal development is controlled by Hox genes, which signal the times and places to develop structures such as body segments and limbs. Animals have several characteristics that they share with other living things. The word animal comes from the Latin noun animal of the same meaning, which is itself derived from Latin animalis ‘having breath or soul’. They have complex ecologies and interactions with each other and their environments, forming intricate food webs.

Lancelets are small fish-like animals with translucent bodies. Sea squirts are tube-shaped sea animals, which, after a short time spent as free swimming larvae, affix themselves onto the sea bed. While invertebrates exhibit a wide range of body plans and structures, vertebrates have a more standardized body plan due to their shared backbone structure. Vertebrates and invertebrates are two major divisions within the kingdom Animalia, differentiated primarily by the presence or absence of a backbone.

The world’s oceans are home to a greater number of mollusk species than to species of Animal Therapy Benefits any other animal group. Most crustaceans live in the sea, but some, such as woodlice, are adapted to living on land. Insects are quite possibly the most successful group of animals ever to have existed. In fact, corals are invertebrate animals that, in their larval form, are able to swim.