Crocodylus
Genus of reptiles
From Wikipedia, the free encyclopedia
Crocodylus is a genus of true crocodiles in the family Crocodylidae.
| Crocodylus | |
|---|---|
| |
| Mugger crocodile (C. palustris) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Archosauria |
| Order: | Crocodilia |
| Superfamily: | Crocodyloidea |
| Family: | Crocodylidae |
| Subfamily: | Crocodylinae |
| Genus: | Crocodylus Laurenti, 1768 |
| Type species | |
| Crocodylus niloticus Laurenti, 1768 | |
| Species | |
 | |
| Worldwide distribution of Crocodylus | |
| Synonyms[1] | |
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Taxonomy
The generic name, Crocodylus, was proposed by Josephus Nicolaus Laurenti in 1768.[2] Crocodylus contains 13–14 extant (living) species and 5 extinct species. There are additional extinct species attributed to the genus Crocodylus that studies have shown no longer belong, although they have not yet been reassigned to new genera.[3]
Extant species
The 13–14 living species are:
| Image | Scientific name | Taxon authority | Common name | Distribution |
|---|---|---|---|---|
,_NPSPhoto_(9255693421).jpg) | Crocodylus acutus | (Cuvier, 1807) | American crocodile | Southern Florida and the Atlantic and Pacific coasts of north Mexico to North America as far south as Peru and Venezuela, Cuba, Jamaica, Hispaniola and Grand Cayman. |
| Crocodylus halli[4] | Murray, Russo, Zorrilla & McMahan, 2019 | Hall's crocodile | southern New Guinea | |
 | Crocodylus intermedius | (Graves, 1819) | Orinoco crocodile | Colombia and Venezuela |
 | Crocodylus johnstoni | Krefft, 1873 | Freshwater crocodile | Northern regions of Australia |
 | Crocodylus mindorensis | Schmidt, 1935 | Philippine crocodile | Northern Sierra Madre Natural Park within the Luzon rainforest, San Mariano, Isabela, Dalupiri island in the Babuyan Islands, Abra (province) in Luzon and the Ligawasan Marsh, Lake Sebu in South Cotabato, Pulangi River in Bukidnon, and possibly in the Agusan Marsh Wildlife Sanctuary in Mindanao |
 | Crocodylus moreletii | (A. H. A. Duméril & Bibron, 1851) | Morelet's crocodile or Mexican crocodile | Mexico, Belize and Guatemala |
 | Crocodylus niloticus | Laurenti, 1768 | Nile crocodile or African crocodile, (the subspecies found in Madagascar, C. n. madagascariensis, is sometimes called the black crocodile) | Israel and Syria (historically), Somalia, Ethiopia, Uganda, Kenya, Egypt, the Central African Republic, the Democratic Republic of the Congo, Equatorial Guinea, Tanzania, Rwanda, Burundi, Zambia, Zimbabwe, Gabon, Angola, South Africa, Malawi, Mozambique, Sudan, South Sudan, Botswana, and Cameroon |
 | Crocodylus novaeguineae | Schmidt, 1928 | New Guinea crocodile | northern New Guinea |
_from_Ranganathittu_Bird_Sanctuary_JEG4362.JPG) | Crocodylus palustris | (Lesson, 1831) | Mugger crocodile, marsh crocodile, or Indian crocodile | southern Iran, southern Pakistan, southern Nepal, India, Sri Lanka |
 | Crocodylus porosus | Schneider, 1801 | Saltwater crocodile or estuarine crocodile | Eastern India, Sri Lanka, Southeast Asia and Northern Australia |
 | Crocodylus rhombifer | (Cuvier, 1807) | Cuban crocodile | Cuba |
.jpg) | Crocodylus siamensis | Schneider, 1801 | Siamese crocodile | Indonesia (Borneo and possibly Java), Brunei, East Malaysia, Laos, Cambodia, Myanmar, Thailand and Vietnam. |
 | Crocodylus suchus | Geoffroy, 1807 | West African crocodile or desert crocodile | Mauritania, Benin, Liberia, Nigeria, Niger, Cameroon, Chad, Central African Republic, Equatorial Guinea, Senegal, Mali, Guinea, Gambia, Burkina Faso, Ghana, Gabon, Togo, Ivory Coast and Republic of Congo |
 | Crocodylus raninus (Considered to be a synonym of Crocodylus porosus; its status remains unclear).[5] | S. Müller & Schlegel, 1844 | Borneo crocodile | Borneo |
Fossils
Crocodylus also includes six extinct species:[3]
- † Crocodylus anthropophagus is an extinct crocodile from Plio-Pleistocene of Tanzania.
- † Crocodylus checchiai is an extinct crocodile from Late Miocene of Kenya.
- † Crocodylus falconensis is an extinct crocodile from Early Pliocene of Venezuela.
- † Crocodylus palaeindicus is an extinct crocodile the Miocene to the Pleistocene of southern Asia.
- † Crocodylus thorbjarnarsoni is an extinct crocodile from Plio-Pleistocene of Kenya.
- † Crocodylus sudani is an extinct crocodile from the Late Pleistocene of Sudan.
Evolution
While taxonomists generally agree that the crown group of Crocodylus appeared ~16 - 14 million years ago, there is an ongoing debate discussing whether the genus has an African or Indo-Pacific origin.[6][7] Proponents of the African origin point towards phylogenetic evidence suggesting that the most recent common ancestor of Crocodylus and its sister genus, Voay, diverged around 25 million years ago near the Oligocene/Miocene boundary.[6] This theory is supported by the existence of closely related African genera Osteolaemus and Mecistops.[6]
Proponents of the Indo-Pacific origin claim that the origin of the genus closely coincides with the appearance of the oldest known species, Crocodylus palaeindicus, in South Asia.[8] Additionally, mitochondrial analysis consistently places Indo-Pacific species Crocodylus mindorensis, Crocodylus novaeguineae, and Crocodylus johnstoni in the basal-most clade of the genus.[8][9] All known New World and African crocodylus species have a much more recent evolutionary origin.[8] While the exact origins of the genus remain uncertain, the most recent common ancestor of the species likely utilized osmoregulatory adaptations, including lingual salt glands, to radiate across the tropics.[7]
Phylogeny
A 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data established the inter-relationships within Crocodylidae.[10] In 2021, Hekkala et al. were able to use paleogenomics, extracting DNA from the extinct Voay, to better establish the relationships within Crocodylidae, including the subfamilies Crocodylinae and Osteolaeminae.[6] In 2023, Sales-Oliveira et al. suggested the relationships of recently recognised species (M. leptorhynchus, C. halli and the third Osteolaemus species).[11]
The below cladogram shows the results of the 2021 study, with supplementary data from the 2023 study:
| Crocodylidae |
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| (crown group) |