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.
Crocodylinae is a subfamily of true crocodiles within the family Crocodylidae, and is the sister taxon to Osteolaeminae.
Gavialis is a genus of crocodylians that includes the living gharial Gavialis gangeticus and one known extinct species, Gavialis bengawanicus.G. gangeticus comes from the Indian Subcontinent, while G. bengawanicus is known from Java. Gavialis likely first appeared in the Indian Subcontinent in the Pliocene and dispersed into the Malay Archipelago through a path called the Siva–Malayan route in the Quaternary. Remains attributed to Gavialis have also been found on Sulawesi and Woodlark Island east of the Wallace Line, suggesting a prehistoric lineage of Gavialis was able to traverse marine environments and reach places possibly as far as western Oceania.
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. 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 River, 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 gharial, also known as gavial or fish-eating crocodile, is a crocodilian in the family Gavialidae and among the longest of all living crocodilians. Mature females are 2.6 to 4.5 m long, and males 3 to 6 m. Adult males have a distinct boss at the end of the snout, which resembles an earthenware pot known as a ghara, hence the name "gharial". The gharial is well adapted to catching fish because of its long, narrow snout and 110 sharp, interlocking teeth.
The false gharial, also known by the names Malayan gharial, Sunda gharial and tomistoma, is a freshwater crocodilian of the family Gavialidae native to Peninsular Malaysia, Borneo, Sumatra and Java. It is listed as Endangered on the IUCN Red List, as the global population is estimated at around 2,500 to 10,000 mature individuals.
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.
The dwarf crocodile, also known as the African dwarf crocodile, broad-snouted crocodile or bony crocodile, is an African crocodile that is also the smallest extant (living) species of crocodile.
Mecistops is a genus of crocodiles, the slender-snouted crocodiles, native to sub-Saharan Africa.
Harpacochampsa is a poorly known Early Miocene crocodilian from the Bullock Creek lagerstätte of the Northern Territory, Australia. The current specimen consists of a partial skull and fragments of a long, slender snout reminiscent of that of a false gharial, demonstrating that it was a piscivore in life.
Euthecodon is an extinct genus of long-snouted crocodile. It was common throughout much of Africa during the Neogene, with fossils being especially common in Kenya, Ethiopia, and Libya. Although superficially resembling that of gharials, the long snout was a trait developed independently from that of other crocodilians and suggests a diet of primarily fish. Euthecodon coexisted with a wide range of other crocodiles in the areas it inhabited before eventually going extinct during the Pleistocene.
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.
Osteolaeminae is a subfamily of true crocodiles within the family Crocodylidae containing the dwarf crocodiles and slender-snouted crocodiles, and is the sister taxon to Crocodylinae.
Brevirostres is a paraphyletic group of crocodilians that included alligatoroids and crocodyloids. Brevirostres are crocodilians with small snouts, and are distinguished from the long-snouted gharials. It is defined phylogenetically as the last common ancestor of Alligator mississippiensis and Crocodylus niloticus and all of its descendants. This classification was based on morphological studies primarily focused on analyzing skeletal traits of living and extinct fossil species, and placed the gharials outside the group due to their unique skull structure, and can be shown in the simplified cladogram below:
The West African crocodile, desert crocodile, or sacred crocodile is a species of crocodile related to — and often confused with — the larger and more aggressive Nile crocodile.
Brochuchus is an extinct genus of crocodile known from the Early Miocene Hiwegi Formation of Rusinga Island in Lake Victoria, Kenya; it was originally named as a species of Crocodylus. It contains two species, B. parvidens and B. pigotti. Brochuchus belongs to the family Crocodylidae, which includes all living crocodiles. The closest living relative of Brochuchus is Osteolaemus, the dwarf crocodile. Compared to Osteolaemus, which has a small body and blunt snout, Brochuchus has a more generalized crocodylid anatomy. Brochuchus is characterized by a flat and relatively narrow skull, and although it is larger than Osteolaemus it is smaller than most other crocodylids. It has two prominent bumps on the surface of its snout.
The Central African slender-snouted crocodile is one of two species of crocodiles in the genus Mecistops. It was once thought to be a population of the West African slender-snouted crocodile but was elevated to a species after two detailed studies, one in 2014 and the other in 2018.
Kinyang is an extinct genus of osteolaemine crocodile from the Early to Middle Miocene of Kenya. Two species are currently known, K. mabokoensis from the Lake Victoria basin and K. tchernovi from the Lake Victoria and Lake Turkana basin. Kinyang had an exceptionally broad and robust skull, much wider than that of any living crocodile species. This might have allowed it to attack and kill prey its own size or even bigger. Kinyang is notably larger than its contemporary relative Brochuchus. While the precise reasons for the extinction of Kinyang are not known, it coincides with a larger faunal turnover that saw osteolaemines replaced by the still dominant crocodylines. One reason for this shift may have been the drying climate of Africa at the time, which caused rainforests to be replaced by more open environments and disrupted the nesting behavior of osteolaemines due to their dependence on foliage.
