Crocodiles inhabit brackish and saltwater habitats and are typically found in coastal mangrove wetlands, ponds, coves, creeks and canals. Decidedly less aggressive than the infamous Nile and Australian crocodiles, American crocodiles are shy, reclusive and rarely seen by people.
Crocodylus is a genus of true crocodiles in the family Crocodylidae.
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]
The 13–14 living species are:
Crocodylus also includes five extinct species:[3]
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]
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 OsteolaeminaeMecistops cataphractus West African slender-snouted crocodile
Osteolaemus osborni Osborn’s dwarf crocodile
Osteolaemus tetraspis Dwarf crocodile
CrocodylinaeVoay†
CrocodylusCrocodylus Tirari Desert†
Asia+AustraliaCrocodylus 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 WorldCrocodylus suchus West African crocodile
Crocodylus niloticus Nile crocodile
New WorldCrocodylus moreletii Morelet's crocodile
Crocodylus rhombifer Cuban crocodile
Crocodylus intermedius Orinoco crocodile
Crocodylus acutus American crocodile
(crown group)Crocodylus is a genus of true crocodiles in the family Crocodylidae.