Animals

Sandfly (Phlebotomine flies): biology, medical importance, and prevention Sandfly Small blood-feeding flies (Phlebotominae) that transmit parasites such as leishmaniasis; overview of their biology, distribution, life cycle, bites, public-health impact and contro…

Sandhill crane (Grus canadensis) Sandhill crane A large, long-legged migratory bird of North America known for loud trumpeting calls, elaborate dances, wetland nesting, and seasonal movements between Canada/northern U.S. and Mex…

Sandpiper (Scolopacidae): shorebirds that probe mudflats and coasts Sandpiper Sandpipers are a diverse family of shorebirds (Scolopacidae) known for probing mud and sand for invertebrates. This article covers their appearance, behaviour, breeding, migration,…

Sandworm: marine worms, bait species, and the fictional desert nemesis Sandworm Sandworm is a common name for several sandy-shore polychaete worms (ragworms, lugworms) and for the giant fictional creature in Frank Herbert's Dune. Biology, ecology, uses and cul…

Santa Catalina Rattlesnake (Crotalus catalinensis) Santa Catalina rattlesnake A venomous pit viper endemic to Santa Catalina Island in the Gulf of California, known for its reduced or absent rattle, island adaptations, and conservation concerns from its tiny…

Santa's Little Helper — The Simpsons' family greyhound Santa's Little Helper Santa's Little Helper is the Simpson family's pet greyhound from The Simpsons, introduced in the series premiere. This article covers his origins, characteristics, notable episodes…

Sapito Rugoso del Marahuaka (Metaphryniscus sosae) Sapito Rugoso Del Marahuaka A small, specialized toad species endemic to high-elevation forests of Venezuela. Monotypic genus, lives in moist montane forest and tepui environments; limited range and habitat s…

Sarcopterygii (lobe‑finned fishes) Sarcopterygii Sarcopterygii are lobe‑finned bony fishes—including lungfishes and coelacanths—originating in the Silurian; one lineage led to tetrapods and terrestrial vertebrates.

Sarcosaurus: an Early Jurassic basal theropod Sarcosaurus Sarcosaurus is a genus of early Jurassic basal theropod known from fragmentary remains in Britain. A small to medium, lightly built carnivore, it helps illuminate early theropod an…

Sarcosuchus — the giant Cretaceous crocodyliform Sarcosuchus Sarcosuchus was a huge crocodile-like crocodyliform from the Lower Cretaceous of Africa, known from large skulls and several partial skeletons that reveal its size, ecology, and sc…

Sardine (pilchard): small oily fish of the herring family Sardine Sardines (also called pilchards) are small, oily clupeid fish related to herrings. This article explains their identity, taxonomy, culinary uses, canning, naming history, and commo…

Šarplaninac (Sharplaninec) — Balkan Shepherd and Livestock Guardian Dog Šarplaninac Large livestock guardian dog from the Šar mountains of the Balkans, known for protective instincts, thick double coat, and long history with pastoral communities across the region.

Sarus crane (Antigone antigone) Sarus crane Large non‑migratory crane of South and Southeast Asia and Australia; the tallest flying bird, dependent on wetlands, socially monogamous, and vulnerable to habitat loss and disturb…

Saurischia: the 'lizard-hipped' dinosaurs Saurischia Saurischia is one of two traditional orders of dinosaurs, including theropods and sauropods. This article explains their anatomy, subgroups, history of classification, links to mod…

Saurolophus: duck‑billed dinosaur with a distinctive forehead crest Saurolophus Saurolophus was a Late Cretaceous hadrosaur (duck‑billed dinosaur) known for a short bony spike on its forehead, with many specimens and skin impressions found in North America and…

Sauropelta — early armoured nodosaurid of the Early Cretaceous Sauropelta Sauropelta, a well-preserved nodosaurid from the Early Cretaceous of North America, is notable for heavy armour, long tail, neck spines and a rich fossil record in Wyoming and Mont…

Saurophaganax — a large allosaurid predator of the Late Jurassic Saurophaganax Saurophaganax was a very large allosaurid theropod from the Morrison Formation (Late Jurassic). This article reviews its discovery, anatomy, debated classification, size estimates…

Sauropoda: the long-necked giant dinosaurs Sauropod Sauropods (Sauropoda) were large, long-necked herbivorous saurischian dinosaurs with pillar-like legs and peg-like teeth, widespread from the Late Triassic to the end-Cretaceous ex…

Sauropodomorpha: the long-necked herbivorous dinosaurs Sauropodomorph Sauropodomorpha is a major clade of long-necked, mostly herbivorous dinosaurs that includes early prosauropods and the giant quadrupedal sauropods, known for enormous size, columna…

Sauroposeidon: the giant brachiosaur-like sauropod Sauroposeidon Sauroposeidon, a giant Early Cretaceous sauropod from North America, is known from exceptionally long neck vertebrae and is notable for its great height, pneumatic bones, and limit…

Sauropterygia — Mesozoic marine reptiles Sauropterygia Extinct clade of Mesozoic marine reptiles that evolved paddle-like limbs and diversified into forms such as plesiosaurs, pliosaurs and nothosaurs from the Triassic through the Cret…

Saurornithoides: a small, birdlike troodontid of the Late Cretaceous Saurornithoides Saurornithoides was a small, agile troodontid theropod from the Late Cretaceous of Asia, known for its large eyes, raised sickle-like second toe claw, and fossils recovered in the…

Savannah cat A hybrid breed created by crossing the African serval with domestic cats. Noted for long legs, spotted coats, high jumps and intelligence. Ownership, care, breeding and legal statu…

Savannah monitor (Varanus exanthematicus) Savannah monitor A medium-sized African monitor lizard, the savannah monitor (Varanus exanthematicus) is ground-dwelling, burrow-building and feeds mainly on hard-shelled invertebrates; commonly ke…

Sawfish (Pristidae): anatomy, ecology, and conservation Sawfish Sawfish are large, ray-like cartilaginous fishes with a toothed rostrum. This article summarizes their anatomy, behaviour, habitat, distribution, life history and conservation conc…

Sawfly (suborder Symphyta) — plant-feeding hymenopterans Sawfly Sawflies are plant-eating insects in the suborder Symphyta of Hymenoptera. They have broad waists, caterpillar-like larvae and a saw-like ovipositor; some species can defoliate tre…

Animal Scales: Structure, Function and Diversity Scale (zoology) An overview of scales in animals: definition, types, development, functions and noteworthy differences among fish, reptiles and insects.

Scale insect (superfamily Coccoidea) Scale insect Small sap-sucking insects in the superfamily Coccoidea. Many species are plant parasites with sessile females, varied reproductive strategies, and significant impacts on agricultur…

Scalloped hammerhead (Sphyrna lewini) Scalloped hammerhead A widespread hammerhead shark with a notched cephalofoil, found in warm coastal waters. Known for schooling and vulnerable to overfishing and the fin trade; subject of conservation…

Scaphognathus: a Late Jurassic rhamphorhynchoid pterosaur Scaphognathus Scaphognathus, from the Solnhofen limestones of the Late Jurassic, was a small long-tailed pterosaur with a leaf-shaped tail vane, short robust skull, and wingspan near one metre.

Scaphopoda (tusk shells): biology, fossil record and human connections Scaphopoda Scaphopoda, or tusk shells, are a small class of marine molluscs with tubular, tusk-like shells. This article describes their anatomy, ecology, fossil history, classification and c…

Scapula (shoulder blade) Scapula The scapula, or shoulder blade, is a flat triangular bone of the pectoral girdle. It links the upper limb to the trunk, serves as a muscle attachment platform, and forms the socket…

Scarlet macaw (Ara macao) — large red parrot of the Neotropics Scarlet macaw A brightly colored Neotropical parrot, Ara macao is known for red plumage, long tail, loud calls and dependence on humid lowland forests; threatened locally by habitat loss and the…

Scarlet Tanager (Piranga olivacea) Scarlet tanager A medium-sized North American songbird noted for the male's bright red breeding plumage and high-canopy nesting. A long-distance migrant that winters in tropical America and nests…

Scarlet tiger moth (Callimorpha dominula) Scarlet tiger moth A colourful, day‑flying tiger moth of Europe and western Asia noted for its red hindwings, cryptic forewings, and well‑studied colour polymorphism important to evolutionary researc…

Scelidosaurus — an early armoured herbivorous dinosaur Scelidosaurus Scelidosaurus, a basal thyreophoran from the Early Jurassic of England, is known from well-preserved skeletons. Its anatomy, armour, diet and basal position illuminate early armour…

Schnauzer — German dog breed: Miniature, Standard and Giant overview Schnauzer Schnauzer, a German dog breed noted for its beard and eyebrows, encompasses Miniature, Standard and Giant varieties. This article covers appearance, history, temperament, grooming…

Schomburgk's deer — an extinct lowland deer of Thailand Schomburgk's deer Schomburgk's deer (Rucervus schomburgki) was endemic to central Thailand, described in 1863 and declared extinct in 1938. Its disappearance is a case study in hunting and habitat c…

Scimitar oryx (Oryx dammah): description, habitat, and conservation Scimitar oryx Large antelope native to North Africa, the scimitar oryx (Oryx dammah) is extinct in the wild but persists in captivity and reintroduction programs. This article summarizes its app…

Scipionyx — exceptionally preserved Cretaceous theropod from Italy Scipionyx Scipionyx samniticus is a tiny Cretaceous theropod known for exceptional soft‑tissue preservation, offering rare insight into dinosaur internal anatomy, growth and taphonomy.

Scissor-tailed flycatcher (Tyrannus forficatus) Scissor-tailed flycatcher A North American flycatcher noted for its very long forked tail, aerial courtship display and insect diet; common on open prairies and the state bird of Oklahoma.

Scorpion Scorpions are predatory arachnids with a segmented tail and venomous sting. This article summarizes their anatomy, evolution, behavior, venom risks, habitats, and notable facts.

Scottish Fold: the folded‑ear cat breed Scottish Fold Overview of the Scottish Fold cat breed, its appearance, genetics, temperament, history, health considerations, and naming/recognition variations.

Scottish Terrier (Aberdeen Terrier) Scottish Terrier A compact, dignified terrier from Scotland noted for its distinctive silhouette, wiry coat and independent temperament; historically a vermin hunter and today a companion, show, an…

Screech owl (Megascops): small nocturnal owls of the Americas Screech owl Screech owls (genus Megascops) are small, ear-tufted owls native to the Americas. This article covers their appearance, behavior, taxonomy, range, and interactions with people and…

Scutellosaurus — a small early armoured dinosaur Scutellosaurus Small, lightly built herbivorous dinosaur from the Early Jurassic. A basal member of Thyreophora, notable for rows of bony armour and a primarily bipedal stance, known from western…

Scyphozoa — the true jellyfish Scyphozoa Scyphozoa are the 'true jellyfish', a class of mainly medusa-form cnidarians (about 200 species) characterized by a gelatinous bell, tentacles with nematocysts, and a life cycle al…

Sea anemone — biology, ecology, and natural history Sea anemone Sea anemones are sessile marine cnidarians with stinging tentacles. This article explains their anatomy, feeding, movement, reproduction, symbioses (e.g., with clownfish and algae)…