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Abdomen – (in arthropods) the hindmost body segment

Abyssal – inhabiting the deepest part of the ocean (below 2000m)

Aestivation – dormancy that occurs in some animals during a period when conditions are hot and dry

Albinism – genetic mutation resulting in the inability to form melanin pigment

Alpha – the highest ranking member within an animal social group

Altrical – young animals which are born helpless with eyes and ears sealed, and the inability to walk, regulate body temperature,  or excrete without assistance

Altruism – sacrificing resources so that others, typically offspring or close younger relatives, may survive or otherwise benefit

Amniote – a type of vertebrate development in which the developing embryo is contained within a sac of fluid

Amphibian – class of exothermic vertebrates possessing a distinct aquatic larval phase of development and soft, naked skin covered in mucous and poison glands and used for respiration

Anadromous – (in fish) living in saltwater then migrating to freshwater to spawn

Anapsid – possessing no openings in the skull behind the eyes

Antennae – paired sensory organs in invertebrates used for chemo- and mechanoreception

Anthropocene – relating to or denoting the current geological age, viewed as the period during which human activity has been the dominant influence on climate and the environment

Anthropophagy – the act of man-eating

Antler – extensions of the skull grown and shed annually by male deer and used to compete for mates

Anuran – order of amphibians characterized by a head joined directly to the trunk, the lack of a tail, stout forelimbs, and webbed hind limbs adapted for jumping and swimming

Apex Predator – a predator that as a mature adult has no predators of its own

Aposematism – warning coloration in which on conspicuous markings serve to deter potential predators

Arachnid – class of arthropods characterized by having two body segments, book lungs, and up to 12 eyes

Arboreal – adapted for living in trees

Archosaur – subclass of diapsid reptiles including modern crocodilians and birds, as well as their closet extinct relatives including dinosaurs and pterosaurs

Arthropod – phylum of invertebrates characterized by having jointed limbs, segmented bodies, and a chitinous exoskeleton

Artificial Selection – selection by humans of individual organisms to breed the next generation because these individuals exhibit the most desired heritable traits

Artiodactyl – an even-toed ungulate

Autotomy – the voluntary severance by an animal of a part of its body, usually a limb or tail, to escape predation

Baleen – sheets of keratin which hang transversely from the mouths of some whales and allow them to filter prey out of the water column

Barbel – fleshy protuberance near the mouth of some fish used as a sensory orga

Beak – the bill of a bird

Benthic – living on or near the sea floor

Bilateral Symmetry – the arrangement of body components of an animal such that one plane divides the animal into two halves which are approximately mirror images of each other

Binocular Vision – vision that results from the ability of an animal to view an object using both eyes simultaneously and allows for greater depth perception

Bioluminescence – the production of light my living organisms without heat

Biome – biological subdivision of Earth’s surface based on the character of the vegetation

Biped – walking on two legs

Biramous – having two branches

Bird – class of vertebrates characterized by having feathers, a toothless beak, hollow bones, and the ability to fly under their own power

Bivalve – class of molluscs in which the body is laterally compressed, lacks a definite head, and has the soft parts enclosed between two calcareous valves

Blubber – fat layer between the skin of muscles of marine mammals

Body Fossil – preserved body parts of extinct animals consisting of the harder parts (teeth, bones, shells)

Book Lung – (in arachnids) paired respiratory organs composed of many fine layers on the underside of the abdomen

Brackish – water that is a mix of fresh and saltwater

Breed – an artificial mating group derived by humans from a common ancestor

Brooding – (in birds) – protecting eggs and chicks with the wings or body

Browser – an herbivore that feeds on leaves, soft shoots, or fruits of high-growing plants

Bushmeat – meat from non-domesticated animals hunted for food

Caecum – pouch in which some animals contains bacterial populations involved in the digestion of cellulose

Caniform – suborder of the Carnivora including the dogs and their relatives

Canine – conical, pointed tooth situated between the incisors and premolars and used to seize prey

Cannibalism – eating by an animal of members of its own species

Carapace – the top part of a turtle or tortoise shell

Carnassial – teeth adapted for slicing meat, consisting of lower first molar and the upper last premolar

Carnivoran – any mammal in the order Carnivora, characterized by the possession of carnassial teeth

Carnivore – an animal that eats meat

Carrion – the decaying flesh if dead animals

Cartilage – flexible skeletal tissue formed from groups of rounded cells lying in a matrix of collagen fibres

Casque – a helmet-like bony process found on the top of the head

Catadromous – (in fish) living in freshwater then migrating to saltwater to spawn

Catarrhine – (in primates) having nostrils that are close together and open downward

Cementum – bone-like substance which coats the surface of that part of a tooth which is embedded in the jaw and which sometimes coats the enamel of the exposed part of the tooth

Cenozoic -the most recent geological era, starting about 66 million years ago and extending to the present

Cephalopod – class of molluscs characterized by bilateral symmetry, prehensile tentacles, jet propulsion, and a shell that is reduced or absent in most groups

Cephalothorax – (in arthropods) the fused head and thorax

Cervid – family of ungulates containing the deer and characterized by the presence of antlers in the males

Cetacean – order of marine mammals containing whales and dolphins and highly adapted for an aquatic lifestyle

Chelicerae – (in arachnids) the foremost pair of appendages adapted for piercing

Chewing -the act of processing food in the mouth via crushing and grinding with the teeth

Chimera – tissue containing two or more genetically distinct cell types or an individual composed of such cells

Chitin – fibrous substance forming the major component of arthropod exoskeletons

Chromatophore – cell containing pigment

Claspers – (in elasmobranchs) pelvic fins that have been modified into male copulatory organs

Claw – curved, pointed nail on each digit of the foot in birds, lizards, and some mammals

Cloaca – terminal part of the gut into which the alimentary, urinary, and reproductive systems open, leading to a single aperture in the body

Compound Eye – eye that is made up of numerous lenses

Constriction – (in snakes) the act of subduing prey by coiling around it and squeezing

Consumer – an organism that feeds on living or dead organic matter

Convergent Evolution – the development of similar external morphology in organisms which are unrelated as each adapts to a similar way of life

Coprophagy – feeding by the ingestion of fecal pellets that have been enriched by microbial activity during exposure to the external environment

Countershading – protective coloration of some animals in which parts normally in shadow are light and those exposed to the sky are dark

Cranial Kinesis – significant movement of the skull bones relative to each other in addition to movement at the joint between the upper and lower jaw

Creche – a group of young animals gathered in one place for care and protection usually by one or more adults

Crepuscular – active at dusk

Crocodillian – order or reptiles characterized by armored scales, strong conical teeth designed to deliver high bite forces, an elongated snout, and numerous other adaptation for a semiaquatic lifestyle

Crop – (in birds) thin-walled extension of the oesophagus and used for food storage

Crown – the part of the tooth external to the gum

Crustacean – subphylum of arthropods characterized by having two pairs of antennae, compound eyes, and biramous limbs

Cryptid – an animal whose existence has not yet been scientifically proven

Cud – partly digested food returned from the first stomach of ruminants to the mouth for further chewing

Cursorial – adapted for running

Cytotoxin – a toxin that attacks cells

Deciduous – parts of an animal that are shed

Decomposer – an organism which feeds on detritus

Denticle – (in fish) a scale composed of dentine with a pulp cavity, which resembles a tooth

Dentine – a bone-like substance lacking cell bodies and consisting mainly of calcium phosphate in a fibrous matrix

Desert – a large, dry, barren region characterized by a lack of vegetation and water

Detrivore – an organism that feeds dead organic material, typically from plants

Dewclaw – rudimentary inner toe present in some animals

Dewlap – a fold of loose skin hanging below the throat

Diapsid – possessing two openings in the skull behind the eyes

Diastema – a space separating teeth of different functions

Digitigrade – gait in which only the digits make contact with the ground and the hind part of the foot remaining raised

Dinosaur – extinct group of diapsid archosaurian reptiles

Diphiodont – (in mammals) having two sets of teeth in which the first set is shed and replaced

Disruptive Coloration – form of camouflage that breaks up an animal’s outline with a strongly contrasting pattern

Diurnal – active during the day

Domestication – the selective breeding by humans in order to accommodate human needs

Durophagy – eating hard materials, such as shelled invertebrates or bones

Ecdysis – periodic shedding of the exoskeleton by some invertebrates or the outermost layer of skin by some amphibians and reptiles

Echinoderm – phylum of invertebrates characterized by an internal skeleton, a water-based vascular system, some form of radial symmetry, and spiny plates in the skin

Echolocation – the detection of an object my means of reflected sound

Ecology – the scientific study of the interrelationships among organisms and between organisms, and all aspects, living and non-living, of their environment

Egg – the organic vessel in which an animal embryo develops until it can survive on its own

Elasmobranch – subclass of cartilaginous fish having up to seven gill slits, rigid find, spiracle openings behind the jaws, and numerous replaceable teeth

Electrolocation – the detection of an object by its distortion of a weak electrical field generated and sensed by the animal

Enamel – crystals of a calcium phosphate-carbonate salt which are formed from the epithelium of the mouth and which provide a hard outer coating to denticles and to the exposed part of teeth

Endangered Species – a species of organism that is seriously at risk of extinction

Endotherm – a warm-blooded animal that is able to maintain its body temperature by means of internal mechanisms

Erect Posture – walking upright with the limbs positioned directly underneath the body

Estuary – the tidal mouth of a large river, where the tide meets the stream

Eusocial – a social structure in which only one female produces offspring, all other individuals attending to her needs, caring for the young, and performing other tasks as necessary for the welfare of the community

Evolution – change, with continuity in successive generations of organisms

Exoskeleton – the chitinous outer covering found on the on the bodies of arthropods

Exotherm – a cold-blooded animal that is unable to maintain its body temperature by means of internal mechanisms so thus must rely on external mechanisms

Extinction – the elimination of a species

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