West African crocodile | |
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Specimen in Bazoulé, Burkina Faso | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauromorpha |
Clade: | Archosauriformes |
Order: | Crocodilia |
Family: | Crocodylidae |
Genus: | Crocodylus |
Species: | C. suchus |
Binomial name | |
Crocodylus suchus Geoffroy, 1807 | |
Synonyms | |
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The West African crocodile, desert crocodile, or sacred crocodile (Crocodylus suchus) [2] is a species of crocodile related to, and often confused with, the larger and more aggressive Nile crocodile (C. niloticus). [3] [4]
The species was named by Étienne Geoffroy Saint-Hilaire in 1807, who discovered differences between the skulls of a mummified crocodile and those of Nile crocodile (C. niloticus). This new species was, however, long afterwards regarded as a synonym of the Nile crocodile. In 2003, a study resurrected C. suchus as a valid species, [3] and this was confirmed by several other studies in 2011–2015. [5] [6] [7]
Despite the long history of confusion, genetic testing has revealed that the two are not particularly close. The closest relatives of the Nile crocodile are the Crocodylus species from the Americas, while the West African crocodile is basal to the clade of Nile and American crocodiles. [8] [9] [10]
Below is a cladogram based on a 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data, [9] as revised by the 2021 Hekkala et al. paleogenomics study using DNA extracted from the extinct Voay . [10]
Crocodylinae |
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The muzzle is short and thick. The distance between the eyes and the tip of the muzzle is 1.5 to 2 times longer than the width of the muzzle at the level of the front edge of the eyes (1.2 to 1.5 times in case of juveniles). The coloration is generally brown to olive. Juveniles are paler, with black bandings, especially on the tail. Like all other species of crocodiles, the West African crocodile's eyes reflect light at night allowing it to be spotted easily through a flashlight. It is found to be active day and night. It can stay submerged underwater for more than 30 minutes, and can reach speeds of up to 30 km/h (19 mph) in short bursts. On land, it is often observed basking motionless in the sun, often with its mouth agape. [11]
Compared to the Nile crocodile, which can grow over 5 m (16 ft 5 in) in length, the West African crocodile is smaller. It typically grows between 2 and 3 m (6 ft 7 in and 9 ft 10 in) in length, with an occasional male growing over 4 m (13 ft 1 in) in rare cases. [12] Adults weigh between 90 and 250 kg (200 and 550 lb), with particularly large male specimens exceeding 300 kg (660 lb) in weight. [13] [14]
The West African crocodile inhabits much of West and Central Africa, ranging east to South Sudan and Uganda, and south to Democratic Republic of the Congo (in all three countries it may come into contact with Nile crocodiles). [6] [15] Other countries where it is found include Mauritania, Benin, Liberia, Guinea-Bissau, Nigeria, Niger, Cameroon, Chad, Sierra Leone, the Central African Republic, Equatorial Guinea, Senegal, Mali, Guinea, Gambia, Burkina Faso, Ghana, Gabon, Togo, Ivory Coast and the Republic of Congo. [6] As late as the 1920s, museums continued to obtain West African crocodile specimens from the White Nile, but today the species has disappeared from this river. [6]
In Mauritania the species has adapted to the arid desert environment of the Sahara–Sahel by staying in caves or burrows in a state of aestivation during the driest periods, leading to the alternative common name desert crocodile. When it rains, these desert crocodiles gather at gueltas. [16] [17] In much of its range, the West African crocodile may come into contact with other crocodile species and there appears to be a level of habitat segregation between them. The Nile crocodile typically prefers large seasonal rivers in savannah or grassland, while the West African crocodile generally prefers lagoons and wetlands in forested regions, at least where the two species may come into contact. [4] [7] The details of this probable segregations remains to be confirmed for certain. [4] In a study of habitat use by the three crocodile species in Liberia (West African, slender-snouted and dwarf), it was found that the West African crocodile typically occupied larger, more open waterways consisting of river basins and mangrove swamps, and was the species most tolerant of brackish waters. In comparison, the slender-snouted crocodile typically occupies rivers within forest interiors, while dwarf crocodiles are distributed in smaller rivers (mainly tributaries), streams and brooks also within forested areas. [18]
The West African crocodile is less aggressive than the Nile crocodile, [4] but several attacks on humans have been recorded, including fatal ones. [19] Mauritanian traditional peoples who live in close proximity to West African crocodiles revere them and protect them from harm. This is due to their belief that, just as water is essential to crocodiles, so crocodiles are essential to the water, which would permanently disappear if they were not there to inhabit it. Here the crocodiles live in apparent peace with the humans, and are not known to attack swimmers. [16]
The people of ancient Egypt worshiped Sobek, a crocodile-god associated with fertility, protection, and the power of the pharaoh. [20] They had an ambivalent relationship with Sobek, as they did (and do) with C. suchus: sometimes they hunted crocodiles and reviled Sobek, and sometimes they saw him as a protector and source of pharaonic power. C. suchus was known to be more docile than the Nile crocodile and was chosen by the ancient Egyptians for spiritual rites, including mummification. DNA testing found that all sampled mummified crocodiles from the grotto of Thebes, grotto of Samoun, and Upper Egypt belonged to this species [6] whereas the ones from a burial pit at Qubbet el-Hawa are believed on the basis of anatomy to consist of a mix of the two species. [21]
Sobek was depicted as a crocodile, as a mummified crocodile, or as a man with the head of a crocodile. The center of his worship was in the Middle Kingdom city of Arsinoe in the Faiyum, known as "Crocodilopolis" by the Greeks. Another major temple to Sobek is in Kom Ombo; other temples were scattered across the country.
Historically, C. suchus inhabited the Nile in Lower Egypt along with the Nile crocodile. Herodotus wrote that the Egyptian priests were selective when picking crocodiles. Priests were aware of the difference between the two species, C. suchus being smaller and more docile, making it easier to catch and tame. [6] Herodotus also indicated that some Egyptians kept crocodiles as pampered pets. In Sobek's temple in Arsinoe, a crocodile was kept in the pool of the temple, where it was fed, covered with jewelry, and worshipped. When the crocodiles died, they were embalmed, mummified, placed in sarcophagi, and then buried in a sacred tomb. Many mummified C. suchus specimens and even crocodile eggs have been found in Egyptian tombs.
Spells were used to appease crocodiles in ancient Egypt, and even in modern times Nubian fishermen stuff and mount crocodiles over their doorsteps to ward against evil.
The West African crocodile only received wider recognition as a valid species in 2011. Consequently, captives have typically been confused with other species, especially the Nile crocodile. [15] In Europe, breeding pairs of West African crocodiles live in Copenhagen Zoo, Lyon Zoo and Vivarium de Lausanne, and offspring of the first pair are in Dublin Zoo and Kristiansand Zoo. [23] A study in 2015 that included 16 captive "Nile crocodiles" in 6 US zoos (almost a quarter of the "Nile crocodiles" in AZA zoos) found that all but one were actually West African crocodiles. [15]
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.
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. It occasionally inhabits deltas and brackish lakes and rarely also saltwater. Its range once stretched from the Nile Delta throughout the Nile River. Lake Turkana in Kenya has one of the largest undisturbed Nile crocodile populations.
Crocodylus is a genus of true crocodiles in the family Crocodylidae.
The Guelta d'Archei is one of the most famous gueltas in the Sahara. It is located in the Ennedi Plateau, in north-eastern Chad, south-east of the town of Fada. The Guelta d'Archei is inhabited by several kinds of animals, most notably the West African crocodile. Middle Holocene remains, as well as rock paintings, indicate that this species once thrived across most of today's Sahara Desert and in swamps and rivers along South Mediterranean shores. The small group of surviving crocodiles in the Guelta d'Archei represents one of the last colonies known in the Sahara today; the Tagant Plateau colony in Mauritania has likely been extinct since 1996.
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.
The Kachikally crocodile pool is located in the heart of Bakau, Gambia, about 10 miles (16km) from the capital Banjul. It is one of three sacred crocodile pools used as sites for fertility rituals. The others are Folonko in Kombo South and Berending on the north bank.
Voay is an extinct genus of crocodile from Madagascar that lived during the Late Pleistocene to Holocene, containing only one species, V. robustus. Numerous subfossils have been found, including complete skulls, noted for their distinctive pair of horns on the posterior, as well as vertebrae and osteoderms from such places as Ambolisatra and Antsirabe. The genus is thought to have become extinct relatively recently. It has been suggested to have disappeared in the extinction event that wiped out much of the endemic megafauna on Madagascar, such as the elephant bird and Malagasy hippo, following the arrival of humans to Madagascar around 2000 years ago. Its name comes from the Malagasy word for crocodile.
Prodiplocynodon is an extinct genus of basal crocodyloid crocodylian. It is one of the only crocodyloids known from the Cretaceous and existed during the Maastrichtian stage. The only species of Prodiplocynodon is the type species P. langi from the Lance Formation of Wyoming, known only from a single holotype skull lacking the lower jaw.
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.
Crocodyloidea is one of three superfamilies of crocodilians, the other two being Alligatoroidea and Gavialoidea, and it includes the crocodiles. Crocodyloidea may also include the extinct Mekosuchinae, native to Australasia from the Eocene to the Holocene, although this is disputed.
Rimasuchus is an extinct genus of crocodile from the Miocene of Egypt and possibly Libya. Only one species - Rimasuchus lloydi - is currently known. It was previously thought to be a species of Crocodylus, but is now thought to be more closely related to the modern African dwarf crocodiles (Osteolaemus).
Gavialoidea is one of three superfamilies of crocodylians, the other two being Alligatoroidea and Crocodyloidea. Although many extinct species are known, only the gharial Gavialis gangeticus and the false gharial Tomistoma schlegelii are alive today, with Hanyusuchus having become extinct in the last few centuries.
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:
"Crocodylus" megarhinus is an extinct species of crocodile from the Eocene of Egypt. A partial skull was found by British paleontologist Charles William Andrews in the Fayum Depression. Andrews named Crocodylus megarhinus in 1905 on the basis of the holotype skull. A complete skull was also uncovered from Egypt in 1907 but was not recognized as "C." megarhinus until 1927.
Crocodylus palaeindicus is an extinct species of crocodile from southern Asia. C. palaeindicus lived from the Miocene to the Pliocene. It may be an ancestor of the living Mugger crocodile.
Crocodylus falconensis is an extinct species of crocodile known from the early Pliocene of the lower part of the Vergel Member of the San Gregorio Formation of Venezuela. C. falconensis was named in 2013 after Falcón State and is thought to be the basalmost species of Crocodylus found in the Neotropics.
Longirostres is a clade of crocodilians that includes the crocodiles and the gavialids, to the exclusion of the alligatoroids. Defined in 2003 by Harshman et al., Longirostres is a crown group defined phylogenetically as including the last common ancestor of Crocodylus niloticus and Gavialis gangeticus and all of its descendants.