The Nile crocodile (Crocodilus niloticus) actually has a number of suggested subspecies that mostly range through various parts of Africa. It was called msh in Old Egyptian and was referred to by some twenty other words.
Physical Characteristics
Considerable variation exists throughout the range of the Nile crocodile. Generally, it is a large crocodilian, in fact the largest of the African crocodilian, averaging five meters in length but reportedly reaching six meters in rare instances. There are dubious reports of seven meter animals having existed, but these are hard to verify. It is conceivable that some now living in Lake Nasser may attain considerable size. They are known to attain weights of up to 775 kilograms, or about 1,500 pounds. Males are often up to 30 percent larger than the females.
However, there is some evidence that Nile crocodiles in cooler countries, such as. South Africa, reach slightly smaller adult sizes of perhaps four meters. There are two known population of dwarf Nile crocodiles living on the extreme limits of the species' range, in Mali and even the Sahara Desert! However, these are probably not a subspecies at all, but rather populations with stunted growth due to environmental variables. Due to suboptimal conditions, adults average between two and three meters. Juveniles are dark olive brown with black cross-banding on the tail and body. This banding becomes fainter in adults.
Though crocodiles in general look much like alligators, they can be distinguished by their longer, narrower snout and their fourth tooth, which ticks out from the lower jaw rather than fitting neatly into the upper jaw.
In water, crocodiles swim mostly with their tails. Though their back feet are webbed, they rarely use them underwater. On land, they do use their powerful legs to move about, and they only look slow. Nile Crocodiles have been known to gallop at speeds of about thirty miles per hour over short distances.
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