From Academic Kids
A crocodile can be any of the 14 species of large, water-loving reptiles in the family Crocodylidae (sometimes classified instead as the subfamily Crocodylinae). The term is also used more loosely to include all members of the order Crocodylia: that is, the true crocodiles; the alligators and caimans (family Alligatoridae); and the Gharial (family Gavialidae).
The crocodiles (colloquially called crocs), are reptiles that live in a large portion of the tropics in Africa, Asia, the Americas and Australia. Crocodiles tend to live in slow-moving rivers and feed on a wide variety of living and dead mammals and fish. Some species, notably the Saltwater Crocodile of Australia and the Pacific islands, have been known to venture far out to sea.
The larger species of crocodiles can be very dangerous to humans. The Saltwater and Nile Crocodiles are the most dangerous, killing hundreds of people each year in parts of South-East Asia and Africa. American Alligators, and possibly the endangered Black Caiman, are also dangerous to humans.
Crocodiles are very fast over short distances, even out of water. They have extremely powerful jaws and sharp teeth for tearing flesh, but cannot open their mouth if it is held closed, hence there are stories of people escaping from the long-snouted Nile Crocodile by holding its jaws shut. All large crocodiles also have sharp and powerful claws. Crocodiles are ambush hunters, waiting for fish or land animals to come close, then attacking with a rush. As cold-blooded predators, they can survive long periods without food, and rarely need to actively go hunting. Despite their slow appearance, crocodiles are top-level predators in their chosen environment, and various species have been observed attacking and killing lions, large ungulates and even sharks. A famous exception is the Egyptian Plover which enjoys a symbiotic relationship with the species where the bird feeds on parasites that attack crocodiles in the mouth and the reptile encourages the bird to do so.
The largest species of crocodile is the Saltwater Crocodile, found in northern Australia and throughout South-east Asia. It is the largest reptile currently living on Earth. Confusingly, in northern Australia the Saltwater Crocodile is sometimes called an "alligator", which it is not, and the smaller Freshwater Crocodile called a "crocodile". This is possibly because the long-snouted Freshwater Crocodile or "freshie" does look a bit like a miniature Nile Crocodile, while in comparison the "saltie" could be said to look like the far less dangerous American Alligator. So the Alligator Rivers in the Northern Territory are in fact named after the Saltwater Crocodile. This is why some northern Australians will claim that alligators, not crocodiles, are the dangerous ones.
Crocodiles in the wild are protected in many parts of the world, but they also are farmed commercially, and their hide is tanned into leather and used to make handbags, boots, and the like, while crocodile meat is considered a delicacy by connoisseurs. The main commercial species are the Saltwater and Nile crocodiles, while a hybrid of the Saltwater and the rare Siamese Crocodile is also bred in Asian farms. Farming has resulted in increases in Saltwater Crocodile numbers in Australia, as eggs are usually harvested from the wild, so landowners have an incentive to conserve crocodile habitat.
Crocodiles are more closely related to birds and dinosaurs than to most animals classified as reptiles (though all of these are thought to probably be more closely related to each other than to Testudines (turtles and tortises)), and have correspondingly unusual features for reptiles, such as a four-chambered heart.
- ORDER CROCODYLIA
- Family Crocodylidae
- American Crocodile, Crocodylus acutus
- Slender-snouted Crocodile, Crocodylus cataphractus
- Orinoco Crocodile, Crocodylus intermedius
- Freshwater Crocodile, Crocodylus johnstoni
- Philippine Crocodile, Crocodylus mindorensis
- Morelet's Crocodile, Crocodylus moreletii
- Nile Crocodile, Crocodylus niloticus
- New Guinea Crocodile, Crocodylus novaeguineae
- Mugger Crocodile or Marsh Crocodile, or Persian Crocodile, Crocodylus palustris
- Saltwater Crocodile, Crocodylus porosus
- Cuban Crocodile, Crocodylus rhombifer
- Siamese Crocodile, Crocodylus siamensis
- Dwarf Crocodile, Osteolaemus tetraspis
- False Gharial, Tomistoma schlegelii
- Family Alligatoridae: alligators and caimans
- Family Gavialidae: Gavial
- Family Crocodylidae