Some people believe that crocodiles are living dinosaurs. Crocodiles are the largest reptiles known to man. There are two types of crocodile in Australia. One of these species is the Estuarine Crocodile, otherwise known as the Australian Saltwater Crocodile, one of the largest species in the Crocodilian family. For thousands of years no other animal threatened crocodiles. The other species, the Freshwater crocodile, lives in fresh or slightly salty water. They are found from the Kimberleys in Western Australia across the top of northern Australia and down most of the Queensland coast. For thousands of years no other animal threatened, they ruled the wetlands and rivers of the world, but when guns were invented, humans had the ability to hunt and kill crocodiles in great numbers. This resulted in the near extinction of the crocodile.
Freshwater crocodiles live in fresh or slightly salty water; they have a narrow snout and jaws and are smaller than estuarine crocodiles. They will not attack people unless they are cornered or wounded. Estuarine crocodiles are much larger and more dangerous, prefer saltwater habitats, but may be found in fresh water. Their snout is broad, bumpy and short.
Estuarine crocodiles may live to 100 years or more. A 3.0 metre estuarine crocodile may weigh about 100 kilograms, whilst a 5.0 metre one may weigh in excess of 480 kilograms. You cannot determine the age of a crocodile based on its size. The only accurate way to age a crocodile is to take a cross section of bone and count the growth rings, like a tree.
Crocodiles float in water with only their eyes and nostrils showing. They have eyes in the front of their heads, like humans do. This allows them to judge distances when hunting. Crocodiles have a transparent third eyelid that closes over the eye when it is underwater. When crocodiles are underwater they seal their nostrils and shut off their windpipe from their gullet, which allows th...