Crocodiles or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans, the gharial and false gharial among other extinct taxa.
Crocodilia is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 94 million years ago in the Late Cretaceous period and are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria. Members of the order's total group, the clade Pseudosuchia, appeared about 250 million years ago in the Early Triassic period, and diversified during the Mesozoic era. The order Crocodilia includes the true crocodiles, the alligators and caimans, and the gharial and false gharial. Although the term 'crocodiles' is sometimes used to refer to all of these, crocodilians is a less ambiguous vernacular term for members of this group.
An alligator, or colloquially gator, is a large reptile in the Crocodilia order in the genus Alligator of the family Alligatoridae. The two extant species are the American alligator and the Chinese alligator. Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the Oligocene epoch about 37 million years ago.
The American alligator, sometimes referred to colloquially as a gator or common alligator, is a large crocodilian reptile native to the Southeastern United States. It is one of the two extant species in the genus Alligator, and is larger than the only other living alligator species, the Chinese alligator.
The saltwater crocodile is a crocodilian native to saltwater habitats, brackish wetlands and freshwater rivers from India's east coast across Southeast Asia and the Sundaic region to northern Australia and Micronesia. It has been listed as Least Concern on the IUCN Red List since 1996. It was hunted for its skin throughout its range up to the 1970s, and is threatened by illegal killing and habitat loss. It is regarded as dangerous to humans.
The mugger crocodile is a medium-sized broad-snouted crocodile, also known as mugger and marsh crocodile. It is native to freshwater habitats from southern Iran to the Indian subcontinent, where it inhabits marshes, lakes, rivers and artificial ponds. It rarely reaches a body length of 5 m and is a powerful swimmer, but also walks on land in search of suitable waterbodies during the hot season. Both young and adult mugger crocodiles dig burrows to which they retreat when the ambient temperature drops below 5 °C (41 °F) or exceeds 38 °C (100 °F). Females dig holes in the sand as nesting sites and lay up to 46 eggs during the dry season. The sex of hatchlings depends on temperature during incubation. Both parents protect the young for up to one year. They feed on insects, and adults prey on fish, reptiles, birds and mammals.
The black caiman is a crocodilian reptile endemic to South America. With a maximum length of around 5 to 6 m and a mass of over 450 kg (1,000 lb), it is the largest living species of the family Alligatoridae, and the third-largest in the Neotropical realm. True to its common and scientific names, the black caiman has a dark greenish-black coloration as an adult. In some individuals, the pigmentation can appear almost jet-black. It has grey to brown banding on the lower jaw; juveniles have a more vibrant coloration compared to adults, with prominent white-pale yellow banding on the flanks that remains present well into adulthood. The banding on young animals helps with camouflage by breaking up their body outline, on land or in water, in an effort to avoid predation. The morphology is quite different from other caimans but the bony ridge that occurs in other caimans is present. The head is large and heavy, an advantage in catching larger prey. Like all crocodile-like animals, caimans are long, squat creatures, with big jaws, long tails and short legs. They have thick, scaled skin, and their eyes and noses are located on the tops of their heads. This enables them to see and breathe while the rest of their bodies are underwater.
The Chinese alligator, also known as the Yangtze alligator, China alligator, or historically the muddy dragon, is a crocodilian endemic to China. It and the American alligator are the only living species in the genus Alligator of the family Alligatoridae. Dark gray or black in color with a fully armored body, the Chinese alligator grows to 1.5–2.1 metres (5–7 ft) in length and weighs 36–45 kilograms (80–100 lb) as an adult. It brumates in burrows in winter and is nocturnal in summer. Mating occurs in early summer, with females most commonly producing 20–30 eggs, which are smaller than those of any other crocodilian. The species is an opportunistic feeder, primarily eating fish and invertebrates. A vocal species, adults bellow during the mating season and young vocalize to communicate with their parents and other juveniles. Captive specimens have reached age 70, and wild specimens can live past 50.
The Nile crocodile is a large crocodilian native to freshwater habitats in Africa, where it is present in 26 countries. It is widely distributed in sub-Saharan Africa, occurring mostly in the eastern, southern, and central regions of the continent, and lives in different types of aquatic environments such as lakes, rivers, swamps, and marshlands. In West Africa, it occurs along with two other crocodilians. Although capable of living in saline environments, this species is rarely found in saltwater, but occasionally inhabits deltas and brackish lakes. The range of this species once stretched northward throughout the Nile, as far north as the Nile Delta. Generally, the adult male Nile crocodile is between 3.5 and 5 m in length and weighs 225 to 750 kg. However, specimens exceeding 6.1 m (20 ft) in length and 1,000 kg (2,200 lb) in weight have been recorded. It is the largest freshwater predator in Africa, and may be considered the second-largest extant reptile in the world, after the saltwater crocodile. Size is sexually dimorphic, with females usually about 30% smaller than males. The crocodile has thick, scaly, heavily armoured skin.
The American crocodile is a species of crocodilian found in the Neotropics. It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida and the coasts of Mexico to as far south as Peru and Venezuela.
A pack hunter or social predator is a predatory animal which hunts its prey by working together with other members of its species. Normally animals hunting in this way are closely related, and with the exceptions of chimpanzees where only males normally hunt, all individuals in a family group contribute to hunting. When hunting cooperation is across two or more species, the broader term cooperative hunting is commonly used.
The Orinoco crocodile is a critically endangered crocodile. Its population is very small, and they can only be found in the Orinoco river basin in Venezuela and Colombia. Extensively hunted for their skins in the 19th and 20th centuries, it is one of the most endangered species of crocodiles. It is a very large species of crocodilian; males have been reported up to 6.8 m in the past, weighing over 900 kg (2,000 lb), but such sizes do not exist today, 5.2 m being a more widely accepted maximum size. A large male today may attain 4.2 m in length and can weigh up to 450 kg (1,000 lb), while females are substantially smaller with the largest likely to weigh around 225 kg (496 lb). Sexual dimorphism is not as profound as in other crocodilian species. The coloration is light even in adults.
Morelet's crocodile(Crocodylus moreletii), also known as the Mexican crocodile or Belize crocodile, is a modest-sized crocodilian found only in fresh waters of the Atlantic regions of Mexico, Belize and Guatemala. It usually grows to about 3 metres (10 ft) in length. It is a Least Concern species. The species has a fossil record in Guatemala.
The West African slender-snouted crocodile, or slender-snouted crocodile, is a critically endangered species of African crocodile. It is one of five species of crocodile in Africa, the other four being the Central African slender-snouted, Nile, West African and dwarf crocodiles.
A crocodile farm or alligator farm is an establishment for breeding and raising of crocodilians in order to produce crocodile and alligator meat, leather from crocodile and alligator skin, and other goods. Many species of both alligators and crocodiles are farmed internationally. In Louisiana alone, alligator farming is a $60 to $70 million industry.
The Cuban crocodile is a small-medium species of crocodile endemic to Cuba. Typical length is 2.1–2.3 m (6.9–7.5 ft) and typical weight 70–80 kg (150–180 lb). Large males can reach as much as 3.5 m (11 ft) in length and weigh more than 215 kg (474 lb). Despite its smaller size, it is a highly aggressive animal, and potentially dangerous to humans.
Peter Brazaitis is an American herpetologist and forensic specialist in herpetology and worked for the Wildlife Conservation Society from 1954 to 1998. He began as a reptile keeper at the Bronx Zoo, became Senior Keeper in 1967, Assistant Animal Manager in 1970, and Superintendent of Reptiles in 1972. In 1988, he transferred to the Central Park Wildlife Center as Assistant Curator of Animals and became Curator of Animals in 1990, a position he held until his retirement in 1998.
The Saola Working Group (SWG) is a working group of the IUCN Species Survival Commission's Asian Wild Cattle Specialist Group, created in 2006 to protect the saolas and their habitat. The Conservancy works to engage and incorporate local communities in protecting saolas in Annamite Range mountains on the border of Laos and Vietnam. The Saola is one of the most endangered species in the world. Discovered in 1992 it was the first large mammal new to science in more than 50 years and has never been seen by a biologist in the wild. The Saola Working Group is a coalition that includes about 40 experts from the forestry departments of Laos and Vietnam, Vietnam's Institute of Ecology and Biological Resources, Vinh University, biologists and conservationists from Wildlife Conservation Society and the World Wildlife Fund.
Planocraniidae is an extinct family of eusuchian crocodyliforms known from the Paleogene of Asia, Europe and North America. The family was coined by Li in 1976, and contains three genera, Boverisuchus, Duerosuchus and Planocrania. Planocraniids were highly specialized crocodyliforms that were adapted to living on land. They had extensive body armor, long legs, and blunt claws resembling hooves, and are sometimes informally called "hoofed crocodiles".
Vladimir Sokolov was a Russian scientist in the field of zoology and ecology. He was a member of the USSR Academy of Sciences, Russian Academy of Science and the Brundtland Commission. He was one of the pioneers of the Russian environmentalism movement and one of the early global sustainability advocates.
