Sturgeon (family Acipenseridae) Sturgeon Sturgeon are long-lived, primitive ray-finned fishes in the family Acipenseridae, valued for caviar and threatened by overfishing, habitat loss, and dams across the Northern Hemisp…
Stygimoloch — a spiked pachycephalosaur from the Late Cretaceous Stygimoloch Stygimoloch was a dome-headed, spike-backed pachycephalosaurid from Late Cretaceous North America, noted for its unusual skull ornamentation and debated status as a distinct genus…
Styracosaurus — horned ceratopsian of the Late Cretaceous Styracosaurus Styracosaurus is a centrosaurine ceratopsid from the Late Cretaceous of western North America, recognizable by its long nasal horn and array of long spikes projecting from its neck…
Subclass (classification and programming) Subclass A subclass is a category created by subdividing a broader class. The term appears in biological taxonomy, object‑oriented programming, and other classification systems to indicate…
Subspecies: the taxonomic rank below species Subspecies A subspecies is a population or group within a species that is distinct by morphology, genetics, or geography. This article explains characteristics, naming, history, examples, and…
Suchomimus: spinosaurid theropod of the Early Cretaceous Suchomimus Suchomimus was a large spinosaurid theropod with a crocodile‑like snout and conical teeth, known from Early Cretaceous deposits in Africa; evidence suggests a primarily fish‑focuse…
Suchosaurus — the "crocodile lizard" (Cretaceous theropod) Suchosaurus Suchosaurus was a dinosaur known mainly from teeth and fragmentary remains. First thought to be a crocodile, it is now usually placed among theropods and may be related to spinosau…
Sugar glider (Petaurus breviceps) — small gliding marsupial Sugar glider A nocturnal, arboreal marsupial native to Australia and New Guinea, known for its gliding membrane, diet of sap and insects, social behavior, and popularity as a regulated pet.
Suidae: pigs and their relatives Suidae Suidae is the family of even-toed ungulates that includes domestic pigs, wild boars, babirusas and warthogs; they are omnivorous mammals with ecological, cultural and agricultural…
Suina (suiform mammals) Suina Suina, or suiforms, are a suborder of even-toed ungulates including pigs and peccaries. They are generally non-ruminant omnivores with tusk-like canines and long ecological and cul…
Suinae — the pig subfamily (Sus and close relatives) Suinae Suinae is the subfamily of even-toed ungulates that contains domestic pigs, wild pigs and their closest relatives. Article covers features, tribes, fossil history, distribution and…
Sulphur-crested cockatoo A large white cockatoo native to Australia and nearby regions, known for its yellow crest, loud calls, intelligence, long lifespan, and complex interactions with people and agricul…
Sumatran rhinoceros (Dicerorhinus sumatrensis) Sumatran rhinoceros The Sumatran rhinoceros is the smallest, hairy rhino native to Southeast Asian rainforests. Critically endangered, it faces habitat loss and poaching; conservation relies on protec…
Sumatran tiger (Panthera tigris sumatrae) Sumatran tiger A small, critically endangered tiger subspecies endemic to the Indonesian island of Sumatra, threatened by habitat loss and poaching and subject to international conservation effor…
Sun bear (Helarctos malayanus) Sun bear Smallest living bear of Southeast Asian tropical forests, known for a pale chest patch, long tongue for extracting insects and honey, and Vulnerable status due to deforestation and…
Sunda clouded leopard (Neofelis diardi) Sunda clouded leopard A medium-to-large wild cat of Borneo and Sumatra, the Sunda clouded leopard is a distinct species adapted to arboreal life, threatened by habitat loss and hunting and noted for its…
Superb bird-of-paradise (Lophorina superba) Superb bird-of-paradise A small, iridescent passerine from New Guinea known for the male's dramatic cape-and-shield courtship display, sexual dimorphism, and role as an iconic example of sexual selection.
Superb fairy-wren (Malurus cyaneus) Superb fairy-wren Small, long-tailed Australian wren known for the male's electric blue breeding plumage, cooperative social system, petal displays, and adaptability to gardens and woodland in south…
Superb lyrebird (Menura novaehollandiae) Superb lyrebird A large, ground-dwelling Australian songbird famed for an ornate lyre-shaped tail and exceptional ability to mimic natural and human-made sounds.
Superclass (biology): meaning, place in taxonomy and usage Superclass (biology) A taxonomic rank used in Linnaean classification above class and below subphylum, often employed to group related classes (e.g., tetrapods) and sometimes replaced by rankless clade…
Supersaurus — a giant diplodocid sauropod of the Morrison Formation Supersaurus Supersaurus, a large diplodocid sauropod from the Late Jurassic Morrison Formation, is known for its extremely long neck, massive size estimates, and notable specimens including th…
Surinam horned toad (a South American horned frog) Surinam horned toad Overview of the Surinam horned toad: identity, appearance, behavior, habitat, reproduction, role in captivity and conservation of frogs in the genus Ceratophrys.
Swallow (Hirundinidae): overview of aerial insectivorous passerines Swallow Swallows and martins (family Hirundinidae) are agile, aerial-feeding passerine birds known for their streamlined bodies, forked tails, migratory habits and close relationships with…
Swallowtail butterfly (family Papilionidae) Swallowtail butterfly Large, often colorful butterflies of the family Papilionidae. Found worldwide (except Antarctica), with about 550 species including the large birdwing butterflies; notable for tail…
Swan (waterfowl) Swan Large waterfowl of the family Anatidae, swans are long-necked birds known for swimming, plant-based diets, territorial behaviour, and cultural symbolism across many regions.
Swarm (collective animal grouping behavior) Swarm A swarm is a dense aggregation of animals that move or act together. Often used for insects, the concept applies to birds, fish and has inspired robotics and computing models.
Swift (bird): aerial specialist of the family Apodidae Swift Swifts (family Apodidae) are highly aerial insectivorous birds with long wings and tiny feet. They nest on vertical surfaces, include species that use saliva-built nests, and some…
Swordfish (Xiphias gladius): biology, fisheries, and notable facts Swordfish Swordfish (Xiphias gladius) are large, open‑ocean predators known for their distinctive bill, importance to commercial and sport fisheries, and specialized adaptations for hunting…
Sylvacaecilia — the Aleku (Ethiopian) caecilian Sylvacaecilia Sylvacaecilia grandisonae, the Aleku or Ethiopian caecilian, is a limbless amphibian in family Indotyphlidae native to Ethiopia; subterranean, associated with dry forests and ripar…
Symphyla: small, soil-dwelling myriapods Symphyla Symphyla are tiny, translucent myriapods living in soil. They act as decomposers but can damage roots and seedlings in agriculture. This article covers appearance, habitat, behavio…
Taxonomic synonyms: meaning, types, and importance in biological nomenclature Synonym (taxonomy) Taxonomic synonyms are different scientific names that refer to the same taxon. This article explains types of synonyms, rules in botany and zoology, common examples, and why synon…
Syrian hamster (Mesocricetus auratus) — overview, care, and history Syrian hamster Small rodent native to Syria, commonly called the golden hamster. Explains appearance, natural history, domestication, pet care, varieties and use in research.
Tabby cat: coat patterns, origins, and common varieties Tabby cat Tabby describes coat patterns in domestic cats — stripes, spots, swirls or ticking — not a breed. This article explains patterns, genetics, history, common breeds, and cultural not…
Tachinidae: tachinid flies and their roles as parasitoid Diptera Tachinidae Tachinidae are a large, diverse family of parasitoid flies (tachinids) with thousands of species worldwide; they parasitize many insect hosts and are important in natural and appli…
Tadpole — the aquatic larval stage of frogs Tadpole A tadpole is the aquatic larval form of frogs. This article describes appearance, anatomy, development to froglets, ecological roles, life history variations, and conservation conc…
Tail (animal): structure, function, and evolution Tail A tail is the rear extension of many animals' bodies. This article explains types, anatomy, functions (balance, locomotion, communication), evolutionary origin, and notable example…
Taipan (Oxyuranus) — large venomous snakes of Australasia Taipan Taipans are fast, highly venomous snakes of the genus Oxyuranus, native to Australasia. This article summarizes their appearance, species, venom, habitat, behavior and interactions…
Takin (Budorcas taxicolor): The Himalayan goat-antelope Takin The takin is a large, stocky ungulate of the Eastern Himalayas and adjacent China and Myanmar. Known for its unusual head and thick coat, it is the national animal of Bhutan and a…
Talarurus — armored ankylosaur from the Late Cretaceous of Mongolia Talarurus Talarurus is an ankylosaurine dinosaur from the Late Cretaceous of Mongolia, notable for heavy body armor, a robust build and a bony tail club. It helps document Asian ankylosaur e…
Tamaraw (Mindoro dwarf buffalo) Tamaraw The tamaraw (Bubalus mindorensis) is a small, critically endangered wild buffalo endemic to Mindoro, Philippines, threatened by habitat loss, hunting and small population risks.
Tammar wallaby (Macropus eugenii) Tammar wallaby Compact guide to the tammar wallaby: identification, subspecies, distribution, behaviour, reproduction, conservation and its role in scientific research.
Tangvayosaurus — Early Cretaceous basal titanosaur from Laos Tangvayosaurus Tangvayosaurus ('Tang Vay lizard') is a genus of basal titanosaur sauropod from the Aptian–Albian Grès Supérior Formation of Savannakhet, Laos, known from partial remains of two or…
Tanycolagreus — small coelurosaur theropod of the Late Jurassic Tanycolagreus Tanycolagreus is a small coelurosaurian theropod from the Upper Jurassic of western North America, known from a partial skeleton. Its gracile build informs studies of theropod dive…
Tanystropheus: the long‑necked reptile of the Middle Triassic Tanystropheus Tanystropheus was a distinctive long‑necked archosauromorph reptile from the Middle Triassic, known from European and Middle Eastern fossils and notable for its extremely elongated…
Tapaculo: secretive ground‑dwelling passerines of the Americas Tapaculo Tapaculos are small, skulking passerine birds of the family Rhinocryptidae, mostly in South America and the northern Andes; they are cryptic in appearance but notable for distincti…
Tapir Tapirs are stout, browsing mammals in the family Tapiridae, recognizable by a short prehensile snout. They inhabit American and Southeast Asian forests and have a long fossil recor…
Tarantula: large, hairy spiders of the Theraphosidae family Tarantula Overview of tarantulas (family Theraphosidae): appearance, behavior, distribution, ecology, relations with people, and notable facts including defense and silk use.
Tarantula hawk (Pepsis and Hemipepsis spider wasps) Tarantula hawk Large spider-hunting wasps in the family Pompilidae that paralyze tarantulas for their larvae, notable for powerful stings, bright coloration, and ecological roles as predators and…
