The saltwater crocodile has a longer muzzle than the mugger crocodile: its length is twice its breadth at the base. The saltwater crocodile has fewer armor plates on its neck than other crocodilians, and its broad body contrasts with that of most other lean crocodiles, leading to early unverified assumptions that the reptile was an alligator.
1n northern Australia (which includes the northernmost parts of the Northern Territory, Western Australia and Queensland) the Saltwater Crocodile is thriving, particularly in the multiple river systems near Darwin (such as the Adelaide, Mary and Daly Rivers, along with their adjacent billabongs and estuaries) where large (6 metre +) individuals are common. The Australian Saltwater Crocodile population is estimated at somewhere between 100,000 and 200,000 adults. Their range extends from Broome in Western Australia through the entire Northern Territory coast all the way down to Rockhampton in Queensland. The Alligator Rivers of Northern Australia are misnamed due to the resemblance of the saltwater crocodile to alligators as compared to freshwater crocodiles, which also inhabit the Northern Territory. In New Guinea they are also common, existing within the coastal reaches of virtually every river system in the country, along with all estuaries and mangroves. They are also present in varying numbers throughout the Bismarck Archipelago, the Kai Islands, the Aru Islands, the Maluku Islands, and many other islands within the region including Timor, and most islands within the Torres Strait.