Animals

Cuvier's beaked whale (Ziphius cavirostris) Cuvier's beaked whale A widely distributed deep-diving beaked whale, known for extreme dives, elusive behavior, and sensitivity to naval sonar and other human impacts.

Cuvier's dwarf caiman (Paleosuchus palpebrosus) Cuvier's dwarf caiman Small, heavily armored South American caiman species (Paleosuchus palpebrosus). Overview of appearance, behavior, habitat, taxonomy, and conservation status (IUCN: Least Concern).

Cycloramphinae: a subfamily of Neotropical frogs Cycloramphinae Cycloramphinae is a subfamily of neotropical frogs historically placed in Leptodactylidae. They occur in parts of South America and include species adapted to rocky streams and for…

Cymbospondylus — a large, primitive Triassic ichthyosaur Cymbospondylus Cymbospondylus was a long, eel-like ichthyosaur of the Middle and Late Triassic known from Europe and North America; it illustrates an early stage in marine reptile evolution.

Cymothoa exigua — the tongue‑eating louse Cymothoa exigua Cymothoa exigua is a parasitic isopod crustacean that enters fish through the gills and can replace the host's tongue. This article summarizes its biology, life cycle, effects on h…

Cynodonts: mammal-like therapsids and ancestors of mammals Cynodont Cynodonts are a diverse group of therapsids that include the direct lineage to mammals. This article summarizes their anatomy, fossil history, global distribution, and evolutionary…

Cynognathus — a wolf-sized cynodont of the Triassic Cynognathus Cynognathus was a carnivorous cynodont (mammal-like therapsid) that lived on open plains in the Early–Middle Triassic; its fossils are known from South Africa and Argentina.

Cyprinidae: the carp and minnow family Cyprinidae Cyprinidae is the largest family of freshwater fishes, including carps, minnows, goldfish and zebrafish. They are diverse, widespread, ecologically important and economically valua…

Cypriniformes: carps, minnows and their freshwater relatives Cypriniformes An overview of Cypriniformes, a diverse order of freshwater ray-finned fishes including carps, minnows and loaches; their traits, diversity, distribution, uses and conservation iss…

Cyprus cat — the native Cypriot landrace Cyprus cat The Cyprus cat is a native landrace on the island of Cyprus. Not a formal breed, it includes diverse domestic and feral populations with ancient roots, local traditions, and ongoin…

Daboia — Old World vipers (Russell's vipers) Daboia Daboia is a small genus of Old World venomous vipers best known for Russell's viper; medically important snakes in South and Southeast Asia, noted for potent venom and frequent hum…

Dabry's sturgeon (Acipenser dabryanus) Dabry's sturgeon Large sturgeon native to the Yangtze River basin, often called a living fossil. Critically endangered and protected in China; subject of captive-breeding and restoration efforts.

Dachshund (breed of dog) Dachshund Short-legged, long-bodied German dog originally bred to hunt badgers; now kept as a companion. Noted for three coat types, lively temperament, and susceptibility to back problems.

Daddy-long-legs spider (Pholcus phalangioides) Daddy long-legs spider Small, long-legged spider (Pholcus phalangioides) common in houses worldwide; builds loose webs, vibrates when disturbed, feeds on insects and spiders, often called cellar spider a…

Dakotaraptor — large Late Cretaceous dromaeosaurid Dakotaraptor Dakotaraptor, a large feathered dromaeosaurid from the Late Cretaceous of North America, known for its size, sickle claw and quill knobs; important for understanding raptor diversi…

Dalmatian (dog) Medium-sized, spotted breed from Dalmatia known for its white coat with dark spots, high energy, and history as a carriage and firehouse companion. Requires exercise, socialization…

Dalmatian pelican (Pelecanus crispus) Dalmatian pelican Large wetland bird of Eurasia noted for its curly nape feathers, silvery plumage and huge bill pouch; occupies lakes and marshes from southeastern Europe to China and Pakistan.

Damselfly (Zygoptera): appearance, life cycle, behaviour and distribution Damselfly Damselflies are delicate predatory insects (suborder Zygoptera) related to dragonflies. This article summarizes their anatomy, life cycle, behaviour, evolution, habitat and distinc…

Danaini: the milkweed butterflies (tribe Danaini) Danaini Danaini is a tribe of milkweed butterflies in the subfamily Danainae, known for caterpillars that feed on toxic plants, aposematic coloration, mimicry, and the famous migratory Mon…

Danaus eresimus — the Soldier (Tropical Queen) butterfly Danaus eresimus An overview of Danaus eresimus (soldier or tropical queen), a milkweed butterfly of the family Nymphalidae: appearance, life cycle, range, habitat, behavior and distinctions from r…

Daphnia: biology, ecology and uses of water fleas Daphnia Small planktonic crustaceans called water fleas. A concise guide to Daphnia anatomy, habitats, life cycle, ecological role, and importance in research and monitoring.

Darwin's finches: Galápagos birds and a classic example of adaptive radiation Darwin's finches A concise overview of Darwin's finches: their diversity, distinctive beaks, role in the study of natural selection, later research, and their continuing importance for evolutionary…

Darwinopterus: a transitional Jurassic pterosaur Darwinopterus Darwinopterus is a Middle Jurassic pterosaur from China that combines primitive and advanced features. Known from dozens of specimens, it illuminates pterosaur evolution, sexual di…

Darwinsaurus — proposed ornithopod genus from southern England Darwinsaurus Darwinsaurus is a proposed ornithopod genus named from Early Cretaceous material found near Hastings, England. Its history includes prior assignment to Iguanodon and Hypselospinus…

Daspletosaurus Daspletosaurus was a large Late Cretaceous tyrannosaurid from western North America, recognized for a robust skull, small orbital horns, and its role as a top predator in floodplai…

Dasyuridae — carnivorous marsupials of Australia and New Guinea Dasyuridae Dasyuridae is a family of about 55 small to medium carnivorous marsupials including quolls, dunnarts, antechinuses, planigales, phascogales and the Tasmanian devil.

Dasyuromorphia: carnivorous and insectivorous Australasian marsupials Dasyuromorphia Dasyuromorphia are an order of mostly small to medium carnivorous and insectivorous marsupials from Australia, New Guinea and Tasmania, including quolls, dunnarts, the numbat and t…

Death's-head hawkmoth (Acherontia) — overview, biology, and cultural notes Death's-head hawkmoth Three large moth species in the genus Acherontia, notable for a skull-like thoracic mark, loud squeak, and habit of entering honeybee hives; found in Europe, Asia and Africa.

Decapods (Decapoda): ten-footed crustaceans Decapod Decapoda is an order of malacostracan crustaceans that includes crabs, lobsters, shrimp, prawns and crayfish; they are diverse in form, ecology, and economic importance.

Decapodiformes: ten-limbed cephalopods (squid, cuttlefish and kin) Decapodiformes Decapodiformes are a superorder of cephalopods distinguished by ten appendages—eight arms plus two tentacles. Includes squid, cuttlefish and extinct belemnites; notable for jet pro…

Deer (Cervidae): overview, characteristics, distribution and human interactions Deer Deer are hoofed mammals of the family Cervidae. This article summarizes their biology, antlers, distribution, behavior, relationships with people, and conservation issues.

Deinocheirus — giant ornithomimosaur from Late Cretaceous Mongolia Deinocheirus Deinocheirus is a large, unusual ornithomimosaur known from fragmentary arms (1965) and more complete specimens (2014). Its anatomy and diet revealed an omnivorous, bulky ‘ostrich’…

Deinonychus — dromaeosaurid theropod of the Early Cretaceous Deinonychus Deinonychus was a medium-sized dromaeosaurid from the Early Cretaceous of North America, known for its sickle claw and a major role in changing views of dinosaur life and bird orig…

Deinosuchus: the giant alligator relative of the Late Cretaceous Deinosuchus Deinosuchus was a giant, extinct alligatoroid that lived about 80–73 million years ago in North America. Known from fragmentary remains, it was an ambush apex predator with crushin…

Deinotherium: the downward‑tusked prehistoric proboscidean Deinotherium Deinotherium was a large extinct proboscidean with downward‑curving lower tusks that lived from the Miocene to the early Pleistocene across Africa, Europe and Asia.

Delphinus — the common dolphin genus Delphinus Delphinus is a small genus of oceanic dolphins known as common dolphins. Article covers species, appearance, distribution, behavior, taxonomy debates and conservation consideration…

Demersal: organisms that live on or near the bottom of water bodies Demersal Demersal animals live on or close to the beds of seas and lakes. This article explains their habitats, biology, differences from pelagic and benthic organisms, fisheries relevance,…

Dendrobates: a genus of poison dart frogs Dendrobates Dendrobates is a genus of brightly coloured poison dart frogs known for aposematic patterns and potent skin alkaloids; species occur in northern South America and are important in…

Dendrobatoidea: the superfamily of neotropical poison frogs Dendrobatoidea Dendrobatoidea is a neotropical frog superfamily commonly treated as containing two families of small, often brightly colored, diurnal frogs known for alkaloid skin toxins and dive…

Dendrophryniscus: a Neotropical genus of true toads Dendrophryniscus Dendrophryniscus is a small genus of Neotropical true toads found in moist lowland forests of Brazil, parts of the Amazon and the Guianas; they are leaf‑litter amphibians with ecol…

Denman (racehorse) Denman (horse) Denman (2000–2018) was an Irish-bred National Hunt racehorse, nicknamed "The Tank", best known for his front-running style and his 2008 Cheltenham Gold Cup victory and rivalry with…

Dermestidae: skin, carpet, and hide beetles — overview and significance Dermestidae Dermestidae are a family of small scavenging beetles (skin, carpet, larder beetles) known for feeding on dry animal and plant material; they matter in museums, agriculture, househo…

Dermophis gracilior — a Central American caecilian Dermophis gracilior Dermophis gracilior is a legless, burrowing amphibian of the family Caeciliidae found in Costa Rica and Panama, typically in lowland and tropical forests; it is secretive and poorl…

Desert dormouse (Selevinia betpakdalaensis) Desert dormouse A small, little-known dormouse species endemic to Kazakhstan and the sole member of its genus; originally placed in a separate family and later reassigned to Gliridae. Ecology and…

Desert froglet (Crinia deserticola): an overview Desert froglet A concise overview of the desert froglet (Crinia deserticola), a small Australian frog of the Myobatrachidae family found in arid and savanna regions, covering traits, habitat, beh…

Desert locust (Schistocerca gregaria): biology, outbreaks and impacts Desert locust Overview of the desert locust, its biology, outbreak behaviour, historical impact on agriculture across Africa, the Middle East and Asia, and approaches to monitoring and control.

Desert scorpion (Hadrurus arizonensis) Desert scorpion A summary of the desert scorpion — the largest North American scorpion — covering appearance, habitat, behavior, venom, life cycle, and interactions with people.

Devon Rex (cat breed) Devon Rex Small, curly-coated domestic cat breed originating in Devon, England in the late 1950s. Noted for large ears, playful temperament, low-shedding coat and distinctive pixie-like appe…