Below you will find some explanations and scientific terms explaining some of the more technical words used on A-Z Animals.
Table of Contents
Animals are a multi-celled living organisms that are thought to have to developed around 500 million years ago from single-celled marine organisms. The animals body shape generally becomes fixed once the animal reaches maturity although some species of animal undergo series metamorphosis in later life such as the caterpillar which grows wings. Most animals are generally motile which means that they are able to move in their own. Animals are also considered heterotrophs, which means that they must ingest other organisms to survive, either plant or animal organisms. There is no way of knowing exactly how many species of animal exist as so many are found or become extinct each year. Estimates rate it at between 2 million and 50 million different species of animal on Earth.
The sensory feel on the head of an arthropod. Antennae are always present in pairs and can be sensitive to touch, taste, sound and heat. The size and shape of antennae varies widely depending on the animal species and the way in which it's antennae are used.
The bony growth on the head of animals such as deer. Antlers are often much large than horns, branching out as they grow. In most cases, antlers are shed and re-grown every year in connection with the breeding season.
Arboreal locomotion is the movement of animals in trees. In every habitat in which trees are present, animals have evolved to move in them. Some animals may only scale trees occasionally, while others are exclusively arboreal. These habitats pose numerous mechanical challenges to animals moving through them, leading to a variety of anatomical, behavioural and ecological consequences including the evolution of sharper claws and prehensile tails.. Furthermore, many of these same principles may be applied to climbing without trees, such as on rock piles or mountains.
An arthropod is an invertebrate that has an external skeleton (exoskeleton), a segmented body, and jointed leg-like attachments called appendages. The arthropod groups includes insects, arachnids, and crustaceans.
A form of reproduction that involves just one parent, and is most common in invertebrates. Asexual reproduction means that a species can quickly multiply it's population numbers.
Average Clutch Size
The average number of eggs laif at once
Average Life Span
The average time the animal lives for
Average Litter Size
The average number of babies born at once
The average length (L) or height (H) of the animal
The average measurement of how heavy the animal is
A fibrous substance that is found in the mouths of some species of whale, which they use to filter food particles out of the water. The baleen plates grow out of the jaw in the same way as teeth, but trap food in the mouth which the whale then swallows.
When the two eyes face forwards their field of vision overlaps allowing the animal to judge depth.
A grouping of living organisms, including the habitat in which they are found.
Moving on two legs
Birds are warm blooded vertebrates that nest to lay their eggs, from which the bird offspring hatch. The birds skin is also covered in layers of feathers, to keep them warm but the feather also make the bird extremely light so it can fly without trouble. All birds have wings and most can fly over very long distance, some species of bird migrates thousands of mile every year, while others can only fly a few feet. The penguin is one of the only birds in the world that cannot fly as their wings are too small to lift their body. There are around 10,000 species of bird found worldwide, although studies suggest that many more species have become extinct. The bee hummingbird is the smallest species of bird in the world growing to around 5cm, with the ostrich being the largest species of bird and growing to nearly 3m tall.
The nostrils of a whale are on the top of their head, and can be pair or singular.
When an animals leaps out of the water and falls back in with a splash. Breaching is often a behaviour displayed by large whales.
When an animal (birds are common) tricks another species into raising it's young.
Feeding on the leaves that are on trees, bushes and shrubs higher up rather than eating the grass and plants on the ground.
Calcareous (calcium) structures are shells, bones and exoskeletons that are created by many animals to provide both support and protection.
Colours or patterns are often displayed on an animal to help it to blend into it's surroundings. Animals use camouflage to both hide and protect themselves from approaching predators but also to sure that they are not spotted by unsuspecting prey.
Some mammals have canine teeth which are strong and sharply pointed teeth. Canine teeth are generally found at the front of the jaw and are used for piercing and biting prey.
Carnivorous mammals have a carnassial tooth which is a blade-like tooth that is designed to slice through flesh.
A carnivore is an animal that only eats other animals in order to ensure its own survival. Carnivorous animals have a complex digestive system that has adapted to breaking large amounts of meat, and therefore do not need to feed as often as herbivorous and omnivorous animals. Lions, crocodiles and sharks are all good example of animals that are carnivores.
The remains of dead animals.
Cartilage is a rubbery substance that helps to form part of the skeleton in vertebrates.
Cellulose is a complex carbohydrate found in plants that many animals find difficult to break down. Herbivorous grazing animals, are able to digest it with the help of micro-organisms.
Chelicerae are the first pairs of appendages of the front of an arachnids body. Some arachnids have pincers on the end and some spiders can inject venom through them.
An animal belong to the phylum Chordata, which includes all vertebrates.
A hard and shiny case that protect insect pupa, that is often found attached to plants or buried in the soil.
An animals circulatory system involves the animals heart, blood vessels and blood which flows around the animals body, transporting nutrients to cells that need them and removing waste products from others. The blood is powered by the animals heart which beats on average around 100 times a minute (this obviously depends on the animal though).
A level of classifying animals in a phylum. Classes are then sub-divided into further groups known as orders.
Animals such as deer and antelope have hooves that look like they are split in two.
A nest made by insects of woven silk, often to protect eggs or pupae.
Having a body temperate that is reliant on it's surroundings.
A group of animals from the same species, that spend their lives together and often have individual tasks that help with the overall survival of the colony.
The colour of the animal's coat or markings
An eye that is divided up into separate compartments, each with its own set of lenses. Compound eyes are most commonly found in arthropods and can contain from a few to thousands of lenses.
The conservation status of a species is an indicator of the likelihood of that species remaining extant either in the present day or the near future. Many factors are taken into account when assessing the conservation status of a species: not simply the number remaining, but the overall increase or decrease in the population over time, breeding success rates and known threats. Scientifically, animals come into 9 different categories which are least concern, near threatened, conservation dependent, threatened, vulnerable, endangered, critically endangered, extinct in the wild and extinct. A-Z Animals groups the animals into just four different categories which are least concern (covering the categories least concern, near threatened and conservation dependent), threatened (covering the categories threatened and vulnerable), endangered (covering the categories endangered, critically endangered and extinct in the wild) and extinct.
- Least Concern is a category assigned to extant species which have been evaluated but do not qualify for any other category. Many common species are assigned to the least concern category but the species has to have been evaluated to be classified in the least concern category.
- Near Threatened is a conservation status assigned to species that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status. As such it is important to re-evaluate Near Threatened species often or at appropriate intervals.
- Conservation Dependent is a category assigned to extant species that rely on conservation efforts to prevent them from being threatened from extinction.
- Threatened species are any species of living organism which are vulnerable to extinction in the near future. The World Conservation Union (IUCN) is the main authority on threatened species, and treats threatened species not as a single category, but as a group of three categories: vulnerable, endangered, and critically endangered, depending on the degree to which they are threatened.
- Vulnerable species are species which are likely to become endangered unless the circumstances threatening their survival and reproduction improve.
- Endangered species are a population of organisms which are at risk of becoming extinct because they are either few in numbers, or threatened by environmental changes or changes in the behaviours of their predators. Many nations have laws offering protection to conservation reliant species: for example, forbidding hunting, restricting land development or creating preserves. Only a few of the many species at risk of extinction actually make it to the lists and obtain legal protection. Many more species become extinct, or potentially will become extinct, without gaining public notice.
- Critically Endangered species are organisms that are of an extremely high risk of becoming extinct in the wild or completely extinct in the immediate future.
- Extinct in the Wild is a conservation status assigned to species where the only known living members are being kept in captivity or as a naturalized population outside it's historic and natural range.
- Extinct species no longer exist anywhere on Earth. The moment of extinction is generally considered to be the death of the last individual of that species.
An animal uses certain colours and markings in order to make itself invisible in its surroundings.
In some mammals, there can be a delay between when the egg is fertilised and when the embryo begins to develop.
An animal that feeds on small particles of organic matter that have drifted down to and settle on the bottom.
An animals that feeds on dead plant and animal matter.
A flap of loose skin that hangs from an animal's neck.
What kind of foods the animal eats
Fingers or toes.
Characteristics unique to the animal
If an animal is diurnal it means that the animal tends to sleep during the dark, night hours and wakes up to hunt when the sun rises in the morning. Humans, bears and horses are considered to be diurnal animals.
An animal that lives with humans or is looked after by them.
Large fin on the back of marine animals such as fish, sharks, whales and dolphins.
Echinoderms are spiny-skinned invertebrates that are found on the ocean floor. Echinoderms are armoured animals that have a hard internal skeleton (endoskeleton) made up of plates and spines. Echinoderms are slow-moving creatures that have a water-vascular system which pumps water through the body. Echinoderms also have small jaws that are supported by the water-vascular system and tube feet which they use to attach to objects for protection, as well as to obtain food. Echinoderms generally have radial symmetry and most can regenerate lost limbs.
A way of sensing nearby objects by using pulse of high-frequency sound.
The term niche is used to describe an animals specific function or purpose within a certain habitat. Most species of animal play an integral part in keeping their surrounding ecosystem running, whether it be the spreading of seeds or predatory animals that hunt smaller species of animal.
The term ecosystem is used to describe the working together of different species of animal within a particular habitat, a good example of this being the basic food chain.
An animal that lives on the surface of another animal's body, generally by sucking it's blood.
A young animal in the first stages of development.
An animal that lives inside another animal's body, both eat the tissues and food.
An internal skeleton that supports an animal's body and is generally made of bone.
The term environment is used to describe the conditions surrounding a certain organism as a whole. This includes everything from the social structure of life contained within that environment from animals to plants, but also is a method of describing how all the different organisms in one area interact with each other. The are numerous different environments throughout the world including desert environments, jungle environments and mountainous environments. The term environment basically refers to all living and non-living things in the world or a particular region.
Evolution is the process by which different species of animals evolve, generally in accordance with natural selection and to make life more successful for the species. For example, certain species of moth have known to completely change colour in just a few generations because of pollution, and the horse we know today evolved from having many toes, to just having a single toe today.
An external skeleton that supports and protects the animal's body.
Fertilisation that occurs outside of the womb, normally in water
When the entire species has disappeared from Earth
A level of classifying animals within an order. Orders are broken down in families and families are broken down further into smaller groups called genus.
The femur is the thigh bone in all vertebrates that have four limbs including elephants, lions and humans.
A feral animal is an animal that was brought up domestically but has then begun to live life in the wild.
The meeting of a female animal's egg cell and a male animal's sperm, which creates a cell able of developing into a new animal.
An animal that feeds by extracting small particles of food out of the water.
Fish are cold blooded vertebrates that live in the waters of rivers, lakes and oceans worldwide. Fish have scales covering their skin and usually an oily layer on the surface of the fishes skin, which helps to regulate the body of temperature of the fish. Fish have gills on the sides of their heads which allows the fish to breath underwater, due to their complex respiratory (breathing) system. There thought to be around 32,000 different species of fish found in freshwater and saltwater sources alike, with over 1,000 of these now considered to be critically endangered. Fish are a stable food source for many species of mammals, birds and reptiles around the world.
The wings and tail feather of a bird that are used in flight.
A flat paddle-shaped limb that many aquatic mammals have.
Many whales and their relatives have a rubbery tail flipper which is known as a fluke.
A developing animal that is nearing the time of birth.
An animal food chain is the sequence of who eats whom within an ecosystem in order for each animal to obtain nutrition. A food chain starts with the primary energy source, which is usually the sun and the food chain is then connected by a series of organisms that eat each other, in turn. The food chain starts with the sun and is then followed by the primary producers, then the primary consumer, then the secondary consumer, followed by the tertiary consumer and finishing with the quaternary consumer which is generally an animal that is eaten by nothing else and is therefore the end of the food chain. Food chains are never the same as each ecosystem contains different organisms within it. If one part of the food chain is missing then there will be high population levels in the links before the missing part of the food chain, as nothing is eating them, and there will also be lower population levels in the links after the missing part in the food chain, as those animals have nothing to eat. The food chain is then said to be out of balance, so it is crucial for food chains to remain unaltered in order for balance within the animal kingdom to remain.
Food Chain: 1. Primary Producer
Primary producers are those organisms that require nothing but the natural resources of the Earth in order to thrive and survive. Primary producers tend to be plants that are photosynthetic and these plants use the energy provided by sunlight in order to make their own food using a process called photosynthesis. Other primary consumers include bacteria that make their own food using chemicals that are produced in natural vents in the ocean. Primary producers are also known as autotrophs and are vital to the survival of the animals that follow in the next stages of the food chain.
Food Chain: 2. Primary Consumer
The primary consumers are the next stage in the food chain behind the sun and the primary producers. The primary consumers are the herbivorous animals of the world and consume the primary producers (autotrophs) in order to gain their nutrition. For example, an insect (primary consumer) will eat the seeds and sprouts that are provided by grass (primary producer). Primary consumers are also known as heterotrophs.
Food Chain: 3. Secondary Consumer
The secondary consumers link in with the food chain as they are the omnivorous animals that eat the primary consumers and the secondary consumers will occasionally eat the primary producers in order to supplement their diet. For example, a rat (secondary consumer) will eat an insect (primary consumer) that has gained its nutrition from eating the grass (primary producer). Secondary consumers are also known as heterotrophs.
Food Chain: 4. Tertiary Consumer
The secondary consumers are followed by the tertiary consumers, the tertiary consumers tend to be the smaller carnivores of the animal kingdom. The tertiary consumers only eat meat and therefore really on the consistency of the secondary consumer populations in order to continue to thrive as a species. For example, a snake (tertiary consumer) will eat a rat (secondary consumer) that has gained its nutrition from eating an insect (primary consumer), and the insect has gained its nutrition from eating the grass (primary producer). Tertiary consumers are also known as heterotrophs.
Food Chain: 5. Quaternary Consumer
The final part to the food chain are the quaternary consumers, and these are the animals that tend to be large carnivores and dominant predators within their natural environment. Quaternary consumers generally have few, if any, natural predators at all and this tends to be where the food chain ends. For example, an eagle (quaternary consumer) will eat a snake (tertiary consumer), that has eaten a rat (secondary consumer), that has eaten an insect (primary consumer), that has eaten the grass (primary producer) that has used the energy from the sun in order to make food.
Food Chain: Examples
Sun --> Grass --> Insect --> Rat --> Snake --> Eagle
Sun --> Phytoplankton --> Krill --> Squid --> Seal --> Polar Bear
The interlinking of a collection of food chains from one habitat.
An animal that feeds on fruit.
A level of classifying animals within a family. Families are divided into sub-groups called genus which generally contain one or two animal species.
The gestation period is the time from conception to birth in which a mammal embryo is developing. The gestation period is different for almost every species of animal, for example, the gestation period for a human embryo is roughly 9 months but the gestation period for a kangaroo embryo is only around 30 days.
An external organ used by aquatic animals such as fish, to extract oxygen out of the water.
Feeding on grass and ground-level plants and foliage.
The domestic group such as cat or dog
The term habitat is used to describe a specific area where a particular animal lives, within an environment. Many animals have adapted to requiring specific conditions which can only be found in their natural habitat such as those animals that live in the polar regions that have longer, thicker body fur to keep them warm.
A herbivore is an animal that only eats plant material, algae and bacteria in order to gain its nutrition. Those animals that are herbivorous have adapted to digest plant material specifically, such as elephants, donkeys and rabbits.
An animal that has both male and female reproductive organs so that it is able to self-fertilize.
When an animal hibernates, it isn't as simple as the animal just sleeping for a long time. When an animal sleeps, the animals brain is still active so the animal is able to move around in their sleep and can also wake up quickly. When an animal hibernates, the animals heart rate slows down, the animals body temperature drops as it is exposed to cold surroundings and the animals breathing slows down meaning that the animal takes longer than usual to wake up. The animal spends the months before it hibernates eating lots of food to make sure its body has enough energy to survive the winter. Some animals are in hibernation for the duration of the winter meaning they don't wake up at all, others wake up every few weeks to have a snack and walk about before going back into hibernation.
The area that an animal or group of animals lives in.
A hard, pointed growth on the head of some mammals.
The animal which a parasite is feeding on or in.
A parasite that attacks other parasites.
A flat tooth at the front of a mammal's jaw that is used for gnawing and slicing food.
The incubation period is the time from when an animal egg is laid to when it hatches. The term incubation period is used to refer to all egg laying mammals like fish, birds and reptiles but also to the platypus and the echidna which are the only egg laying mammals on earth. The incubation period varies between animal species from the incubation period of a penguin egg which is around 60 days to the incubation period of the an iguana egg which is between three and four months.
Insects are invertebrate arthropods, which means that the insects body is made up of sections of shell rather than bones. There are more than 1 million described species of insect found worldwide, but estimates suggest there to be around 30 million different species of insect still left to identify. Insects are found in every habitat around the world from the deserts, to the jungles and in the mountains. Some species of insect also live in or around water such as the mosquito and the dragonfly. Insects generally have a lifespan that is less than a year, although some types of insects such as beetles, have been known to live for more than a few years.
An animal that feeds on insects.
Fertilisation that occurs inside the body of the female.
A species that has been accidentally or purposefully been introduced, by humans, into an eco-system where it is not found naturally.
Invertebrates are animals that do not have a spinal column (back bone), which surprisingly accounts for around 98% of the worlds described animals with the exception of mammals, reptiles, birds and bony fish all of which have a spinal column and are therefore classified as vertebrates, making up the final 2% of described animals.
An enlargement of the breastbone in birds, that secures the muscles during flight.
A strong and resilient structural protein that is found in an animals hair, nails and horn.
A level of classifying all living things on earth, as similar species are broken into 5 groups including plants, animals and fungi.
A young insect that is independent of an looks very different from the adult form. Insect larva become adults through a metamorphic process.
How long the animal lives for
Whether the animal is solitary or sociable
Mammals are warm blooded vertebrates that have mammary glands, which means that the females are able to produce milk to feed their young. Mammals are also the only animal group that gives bird to live young, where the others all lay eggs. Mammals are generally land-dwelling animals but there are exceptions like the blue whale, which is the worlds largest mammal and grows to around 20 times the size of the biggest land mammal, the African elephant, average about 33 meters in length.. The smallest mammal in the world is the bumble bee bat which is only 3.5 cm tall. There are approximately 5,400 different species of mammal found worldwide.
The paired jaws of an arthropod such as ants, crabs and spiders.
A large swelling of fatty-fluid that is found in the heads of many toothed whales, that is believed to improve sound focus used in echolocation.
The rate of an animal's metabolism can be affected by many factors including size and energy.
A mixture of chemical processes that occur within the body of an animal to either release energy (breaking down food) or to consume it (muscle movement).
The metacarpal is one of a set of bones that is found in either or the arm or the leg in all vertebrates with four limbs.
The complete change in body shape when certain animals move from being young animals into adults.
The metatarsal is one of a set of bones found in the back of the leg in all vertebrates with four limbs.
The migration of animals is generally connected with the seasons and involves with travelling between one place and another, often along a well-known route.
When one animal attempts to camouflage itself by resembling another animal or an object such as a leaf or a stick.
A flattened or ridged tooth found at the back of the jaw in mammals, that is used for chewing.
Molluscs are a group of animals that are found in both marine and freshwater habitats. There are nearly 100,000 different species of animal in the mollusc group, which makes up more than 20% of animal life in the water. The octopus and the squid are both molluscs.
Mating with a single partner for life or throughout the breeding season.
The shedding of fur, feathers, scales and skin so that it can be renewed and replaced.
The term environment is used to describe everything in a certain area. This includes the terrain such as mountains and deserts, the natural elements that are found there like water and metal, the climate and all the living and non-living things in that area like animals, plants and objects.
The term natural selection refers to the the process where heritable traits that make it more likely for an organism to survive long enough to reproduce become more common over successive generations of a population. This can include anything from the exterior appearance of an organism (for example those that are most easily camouflaged tend to fair better) to the temperament of an organism (for example, a lion would have more difficulty in hunting prey if it was irrational and clumsy in behaviour instead of being stealthy and systematic in it's actions). Natural selection is a key mechanism of evolution.
North, Central and South America.
New World Monkeys
New World monkeys are the five families of primates that are found in Central and South America. New World monkeys differ from other groupings of monkeys and primates, such as the Old World monkeys and the apes, mainly in the fact that New World monkeys tend to be small to medium in size. The New World monkey group includes the world's smallest monkey, the pygmy marmoset. New World moneys are different from the Old World monkeys in many ways, including the fact that the nose of New World monkeys is flat and has side facing nostrils, the lack of opposable thumbs and due to the fact that most New World monkeys are arboreal, they often have prehensile tails.
An animal's place or role in it's habitat.
If an animal is nocturnal it means that the animal tends to sleep during the daylight hours and wakes up to hunt when night falls. Raccoons, koalas and hedgehogs are all considered to be nocturnal animals.
Number of Species
The total number of recorded species
A young insect that is similar in appearance to it's parents but it does not yet have functioning organs or is able to fly.
Europe, Africa, Asia and Australasia.
Old World Monkeys
The Old World monkeys are native to Africa and Asia today, inhabiting a range of environments from tropical rain forest to savannah, scrubland, and mountainous terrain, and are also known from Europe in the fossil record. However, a (possibly introduced) free-roaming group of monkeys still survives in Gibraltar (Europe) to this day. Old World monkeys include many of the most familiar species of non-human primates such as baboons and macaques. Old World monkeys tend to be medium to large in size and tend to have a predominantly herbivorous diet preferring to eat plant matter rather than other animals. Old World monkeys are known to have an opposable thumb and rarely have prehensile tails.
An omnivore is an animal that eats both plant material and other animals in order to get enough food. Animals that are omnivores have complex digestive systems that are able to deal with both plant animal material equally well, like kangaroos, otters and humans.
Digits that are able to be pressed together from opposite directions, like thumbs in humans and apes.
Optimum pH Level
The perfect acidity conditions for the animal
A level used to classify animals. Classes are broken into sub-groups known as order, which are broken down further into families.
A structure found in an animal's body that is made up of tissues and does a specific task.
In biological terms, an organism is used to describe a living thing whether animal, plant, fungi or micro-organisms. Some organisms are single-celled organisms meaning that they consist of one cell that has a central nerve in the middle, for example bacteria. Other organisms are multi-celled organisms meaning that they consist of many cells all working together, for example humans.
The area where the animal first came from
Reproducing by laying eggs.
An animal that lives on or inside another animal.
A gland found behind the eyes of some amphibians that secretes poison onto the surface of their skin.
An animal species where some individuals migrate but others don't.
One of the two pairs of fins that are found at the front of the body of a fish.
The last pair of fins on the body of a fish, found on the underside, close to the tail.
A chemical produced by an animal which has an effect on animals from the same species but also on other animal species too.
The chemical process which plants use to create energy.
A level of classifying animals within the animal kingdom. Phylum are further divided into subgroups called classes.
The external ear flaps found on mammals.
An organ that is produced by a developing animal that allows it to absorb nutrients from the mother's bloodstream when it is in the womb.
Floating microscopic organisms that drift close to the surface of the sea in open water.
When male animals often made with several female animals throughout the breeding season.
When an animal is referred to as a predator, it means that the animal either hunts or catches other animals. Predatory animals are generally dominant within their environment and will generally hunt animals smaller than themselves.
Other animals that hunt and eat the animal
Prehensile is the term that is given the appendages of animals that have evolved to grasp or hold onto things. For example, some species of monkey and most species of lizard have prehensile tails which allows them to hold onto tree branches with their tails so that they can reach down to collect food. Most species of primates have prehensile hands and cats are known to have prehensile claws. The tongues of many animals are prehensile, particularly that of the giraffe. Elephants and tapirs are known to have prehensile noses, and horses and rhinos have prehensile lips.
A specialised tooth that is found about half-way along the jaw in mammals, that is often used for slicing through flesh.
When an animal is referred to prey, it means that the animal is either hunted or caught for food. Animals that are referred to as prey are generally hunted by bigger animals, although there are a number of exceptions.
The nose of an animal, or parts of the mouth which are nose-like in shape.
In stage in the development of insects when the body of the larva is broken down and turned into the body of an adult.
Movement on four limbs.
Reproduction is the biological process by which new individual organisms are produced. Reproduction is a fundamental feature of all known life as each individual organism exists as the result of reproduction. Reproduction requires a male and female counterpart in order to create new offspring.
Reptiles are cold blooded vertebrates that have scales covering their skin rather than hair or feathers. Reptiles are found on every continent worldwide with the exception of the polar Antarctica. There are more than 8,000 species of recorded reptile split into four main groups. The order Crocodilia contains 23 species that are crocodiles, gavials, caimans, and alligators; the order Sphenodontia are the tuatara from New Zealand, of which there are 2 different species; the order Squamata is lizards, snakes, and amphisbaenids or worm-lizards, of which there are approximately 7,900 species; the order Testudines covers turtles, tortoises, and terrapins with around 300 species found worldwide. Reptiles are also egg laying animal and are known to bask for long hours during the day in the hot sun to heat up the reptiles cold blood, so the reptile has enough energy to hunt at night.
All animals have a respiratory system which allows the animal to take in oxygen from the environment (breath in) that the animals blood needs to stay healthy. The process of respiration produces carbon dioxide as a waste product, which is then eliminated from the animal (breath out) and back into the environment.
A hoofed and herbivorous mammals that has a specialised digestive system with more than one stomach chamber.
Feeding on decaying and dead matter.
Having a lifestyle that involves little movement.
A sessile animal attaches itself to another object and cannot move independently.
The physical differences between males and females.
A fibrous material that is produced by spiders and some insects.
How long (L) or tall (H) the animal is
The animals skeletal system is made up of all the bones, joints and cartilage in the animals body. The animals skeletal system is not only essential for protecting supporting the animals body, but also helps to make new blood cells and stores vital minerals.
The protective layer of the animal
A group of similar animals that are capable of interbreeding that results in the production of fertile offspring.
The breastbone in all vertebrates that have four limbs.
An animal that feeds on the organic particles that are suspended in the water.
The way the animal thinks, behaves or reacts
An animals that spends it's whole life or the majority of it's life on the ground.
An area that is defended by an animal or a group of animals, against animals of the same species.
The bone found in the shin of all vertebrates with four limbs.
A layer of cell in the body of an animal.
The fastest recorded speed of the animal
A breathing tube found in vertebrates, which is known as the windpipe.
The level of house-training needed for the animal
A hard swelling somewhere on the body of an animal.
A modified tooth to protrudes out of the mouth of some mammals.
The animal group that the species belongs to
The dense layer of fur that is closet to the body of the animal to keep it warm.
The part of the body in female mammals where the young are developed.
Vertebrates are animals with a spinal column (back bone) and include mammals, reptiles, birds and fish. There are around 58,000 species of recognised vertebrate in the modern world from fish that are 0.5 cm to the blue whale measuring 33 m!
Giving birth to live young in order to reproduce.
Ability to maintain a consistently warm body temperature, despite the surrounding climate.
The mixture of different colours displayed on an animal that warns other animals that it is dangerous.
Either freshwater, brakish or salt
The period when the female mammal stop providing milk for her young.
The measurement of how heavy the animal is
The measurement from one wing tip to the other
An animal that eats wood.