Asia, Africa, Australia and Americas: Crocodile.

http://en.wikipedia.org/wiki/Crocodile 

Crocodiles (subfamily Crocodylinae) or true crocodiles are large aquatic tetrapods that live throughout the tropics in Africa, Asia, the Americas and Australia. Crocodylinae, in which all its members are considered true crocodiles, is classified as a biological subfamily. A broader sense of the term crocodile, Crocodylidae, that includes the tomistoma, was excluded in this article since new genetic studies reveal the possibility of tomistoma as a close relative of the gharial.^[1] This article applies the term crocodile only to the species within the subfamily of Crocodylinae. The term is sometimes used even more loosely to include all extant members of the order Crocodilia: which includes all members of Crocodylidae, including the tomistoma, the alligators and caimans (family Alligatoridae) and the gharials (family Gavialidae), and the rest of Crocodylomorpha, which includes all of the prehistoric crocodile relatives and ancestors.
Although they appear to be similar to the untrained eye, crocodiles, alligators and the gharial belong to separate biological families. The gharial having a narrow snout is easier to distinguish, while morphological differences are more difficult to spot in crocodiles and alligators. The most obvious external differences are visible in the head with crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to alligators and caimans. Another obvious trait is the upper and lower jaws of the crocodiles are the same width, and teeth in the lower jaw fall along the edge or outside the upper jaw when the mouth is closed; therefore all teeth are visible unlike an alligator; which possesses small depressions in the upper jaw where the lower teeth fit into. Also when the crocodile's mouth is closed, the large fourth tooth in the lower jaw fits into a constriction in the upper jaw. For hard-to-distinguish specimens, the protruding tooth is the most reliable feature to define the family, the species belongs to.^[2] Crocodiles have more webbing on the toes of the hind feet and can better tolerate saltwater due to specialized salt glands for filtering out salt, which are present but non-functioning in alligators. Another trait that separates crocodiles from other crocodilians, are the much higher levels of aggression.^[3] All reptiles are all scaled diapsids, which are divided into two groups: crocodilians are archosaurs, along with birds and the extinct dinosaurs, while other reptiles are lepidosaurs.