A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (coming from the Ancient Greek ἀνούρα, literally 'without tail'). The oldest fossil "proto-frog" Triadobatrachus is known from the Early Triassic of Madagascar (250 million years ago), but molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from taxonomy or evolutionary history.
A gazelle is one of many antelope species in the genus Gazella /ɡəˈzɛlə/. There are also seven species included in two further genera; Eudorcas and Nanger, which were formerly considered subgenera of Gazella. A third former subgenus, Procapra, includes three living species of Asian gazelles.
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from 1.6 to 60 centimetres (0.6 to 23.6 inches).
The giant panda (Ailuropoda melanoleuca), also known as the panda bear or simply panda, is a bear species endemic to China. It is characterised by its white coat with black patches around the eyes, ears, legs and shoulders. Its body is rotund; adult individuals weigh 100 to 115 kg (220 to 254 lb) and are typically 1.2 to 1.9 m (3 ft 11 in to 6 ft 3 in) long. It is sexually dimorphic, with males being typically 10 to 20% larger than females. A thumb is visible on its forepaw, which helps in holding bamboo in place for feeding. It has large molar teeth and expanded temporal fossa to meet its dietary requirements. It can digest starch and is mostly herbivorous with a diet consisting almost entirely of bamboo and bamboo shoots.
The giraffe is a large African hoofed mammal belonging to the genus Giraffa. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes have been thought of as one species, Giraffa camelopardalis, with nine subspecies. Most recently, researchers proposed dividing them into four extant species due to new research into their mitochondrial and nuclear DNA, and individual species can be distinguished by their fur coat patterns. Seven other extinct species of Giraffa are known from the fossil record.
A gnat (/ˈnæt/) is any of many species of tiny flying insects in the dipterid suborder Nematocera, especially those in the families Mycetophilidae, Anisopodidae and Sciaridae. Most often they fly in large numbers, called clouds. "Gnat" is a loose descriptive category rather than a phylogenetic or other technical term, so there is no scientific consensus on what constitutes a gnat. Some entomologists consider only non-biting flies to be gnats. Certain universities and institutes also distinguish eye gnats: the Smithsonian Institution describes them as "non-biting flies, no bigger than a few grains of salt, ... attracted to fluids secreted by your eyes".
The Mongolian gerbil or Mongolian jird (Meriones unguiculatus) is a rodent belonging to the subfamily Gerbillinae. Their body size is typically 110–135 mm (4+1⁄4–5+1⁄4 in), with a 95–120 mm (3+3⁄4–4+3⁄4 in) tail, and body weight 60–130 g (2–4+1⁄2 oz), with adult males larger than females. The animal is used in science and research or kept as a small house pet. Their use in science dates back to the latter half of the 19th century, but they only started to be kept as pets in the English-speaking world after 1954, when they were brought to the United States. However, their use in scientific research has fallen out of favor.
Parrots (Psittaciformes), also known as psittacines (/ˈsɪtəsaɪnz/), are birds with a strong curved beak, upright stance, and clawed feet. They are classified in four families that contain roughly 410 species in 101 genera, found mostly in tropical and subtropical regions. The four families are the Psittaculidae (Old World parrots), Psittacidae (African and New World parrots), Cacatuoidea (cockatoos), and Strigopidae (New Zealand parrots). One-third of all parrot species are threatened by extinction, with a higher aggregate extinction risk (IUCN Red List Index) than any other comparable bird group. Parrots have a generally pantropical distribution with several species inhabiting temperate regions as well. The greatest diversity of parrots is in South America and Australasia.
Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making it the second largest order of sharks, numbering 119 species across 7 families. Having earned their name after a group of fishermen reportedly observed the species chasing down smaller fish in dog-like packs, dogfish have slender, streamlined bodies, usually more compact in comparison to other species, and a pointed snout. Dogfish likewise have two dorsal fins, each with smooth spines, but no anal fin, and their skin is generally rough to the touch. As the species reaches adulthood, males usually measure a maximum of 100 cm (39 inches), while females typically measure 125 cm (49 inches) long. The species therefore exhibits female-dominant sexual dimorphism.
The tiger (Panthera tigris) is a member of the genus Panthera and the largest living cat species native to Asia. It has a powerful, muscular body with a large head and paws, a long tail and orange fur with black, mostly vertical stripes. It is traditionally classified into nine recent subspecies, though some recognise only two subspecies, mainland Asian tigers and the island tigers of the Sunda Islands.