Crocodylus is a genus of true crocodiles in the family Crocodylidae.
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:
Fossils
Crocodylus also includes five extinct species:[3]
Evolution
Crocodylus likely originated in Africa and radiated outwards towards Southeast Asia and the Americas,[6] although an Australia/Asia origin has also been considered.[7] Phylogenetic evidence supports Crocodylus diverging from its closest recent relative, the extinct Voay of Madagascar, around 25 million years ago, near the Oligocene/Miocene boundary.[6]
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.[8] 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]
The below cladogram shows the results of the latest study:
Crocodylidae Osteolaeminae Mecistops cataphractus West African slender-snouted crocodile
Euthecodon†
Brochuchus†
Rimasuchus†
Osteolaemus osborni Osborn’s dwarf crocodile
Osteolaemus tetraspis Dwarf crocodile
Crocodylinae Voay†
Crocodylus Crocodylus anthropophagus†
Crocodylus thorbjarnarsoni†
Crocodylus palaeindicus†
Crocodylus Tirari Desert†
Asia+Australia
Crocodylus johnstoni Freshwater crocodile
Crocodylus novaeguineae New Guinea crocodile
Crocodylus mindorensis Philippine crocodile
Crocodylus porosus Saltwater crocodile
Crocodylus siamensis Siamese crocodile
Crocodylus palustris Mugger crocodile
Africa+New World
Crocodylus checchiai†
Crocodylus falconensis†
Crocodylus suchus West African crocodile
Crocodylus niloticus Nile crocodile
New World
Crocodylus moreletii Morelet's crocodile
Crocodylus rhombifer Cuban crocodile
Crocodylus intermedius Orinoco crocodile
Crocodylus acutus American crocodile
(
crown group)
References
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^ Crocodylus . Retrieved through: Interim Register of Marine and Nonmarine Genera on 17 April 2022.
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^ Laurenti, J.N. (1768). "XV. Crocodylus". Specimen medicum, exhibens synopsin reptilium emendatam cum experimentis circa venena et antidota reptilium austriacorum [Medical Treatise, Exhibiting an Emended Synopsis of Reptiles, with Experiments Concerning Venoms and Antidotes for Austrian Reptiles]. Vienna: Joan. Thom. Nob. de Trattnern. pp. 53–55.
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^ a b Brochu, C.A.; Storrs, G.W. (2012). "A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity of Crocodylus in Africa". Journal of Vertebrate Paleontology. 32 (3): 587. doi:10.1080/02724634.2012.652324. S2CID 85103427.
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^ Murray, Christopher M.; Russo, Peter; Zorrilla, Alexander; McMahan, Caleb D. (2019). "Divergent Morphology among Populations of the New Guinea Crocodile, Crocodylus novaeguineae (Schmidt, 1928) Diagnosis of An Independent Lineage and Description of A New Species". Copeia. 107 (3): 517–523. doi:10.1643/CG-19-240.
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^ Species Crocodylus porosus at The Reptile Database www.reptile-database.org.
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^ a b c Hekkala, E.; Gatesy, J.; Narechania, A.; Meredith, R.; Russello, M.; Aardema, M. L.; Jensen, E.; Montanari, S.; Brochu, C.; Norell, M.; Amato, G. (2021-04-27). "Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus ". Communications Biology. 4 (1): 505. doi:10.1038/s42003-021-02017-0. ISSN 2399-3642. PMC 8079395. PMID 33907305.
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^ Oaks, J.R. (2011). "A time-calibrated species tree of Crocodylia reveals a recent radiation of the true crocodiles". Evolution. 65 (11): 3285–3297. doi:10.1111/j.1558-5646.2011.01373.x. PMID 22023592. S2CID 7254442.
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^ Lee, Michael S. Y.; Yates, Adam M. (27 June 2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil". Proceedings of the Royal Society B. 285 (1881). doi:10.1098/rspb.2018.1071. PMC 6030529. PMID 30051855.