They are often killed by poachers, hoping to earn money by selling their valuable skins. Therefore, as representatives of endangered species, they are bred in special centers and reserves. Crocodiles and alligators belong to a group of reptiles called crocodilians, which are the largest of the living reptiles. A unique species of crocodile lives in New Guinea, but in 1989, a researcher suspected that there may be more to the story on the tropical island. Saltwater crocodiles above 6 m (19.7 feet) were certainly much more common in Australia and SE Asia before extensive hunting for their skins in the 1940's, 50's and 60's wiped out the big crocodiles. This species is the only extant crocodilian to regularly reach or exceed 5.2 m (17 ft 1 in). In addition to being solitary ambush hunters, some species can hunt in groups demonstrating coordination and collaboration among members. Examples include fast runners, digging and burrowing forms, herbivores, and ocean-going species… Many of the skulls were 90 years old… There are 16 extant species: American crocodile (Crocodylus acutus) However, as the population recovers after protection of the species, the number of large crocodiles is increasing, especially in Odisha, where at least one living specimen is estimated to have obtained a length of around 7 m (23 ft 0 in). Each year, the Nile crocodile attacks hundreds of people in Sub-Saharan Africa. Many crocodile species are threatened with extinction. There are also very few species alive today -- just 25. Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago. The crocodiles have had a much greater diversity of forms in the past. Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago. ... to attack and eat humans and the vast majority of both fatal and non-fatal crocodilian attacks are done by the two species – the Nile crocodile and saltwater crocodile. Some old hunters claim to have shot animals over 8 m (26 feet) during this period (e.g. Recent research has shown that crocodiles are intelligent hunters that care for their young and use tools. Crocodile Some species are endangered. Crocodiles have sophisticated communication abilities, including threat calls, distress calls and infrasonic “booming” sounds. For example, the true birds first appear in the fossil record many millions of years after the first crocodiles, yet today they number around 10,000 species, ranging from hummingbirds to ostriches. Do crocodiles and alligators die of old age? Other animals such as lizards and birds have achieved a diversity of many thousands of species in the same amount of time or less. There are also very few species alive today – just 25. Of the 23 different species of crocodilians in the world, 2 species are native to the United States, and south Florida is the only place where both of these species coexist. The earliest evidence of Nile crocodiles in Madagascar is 300 years old, but Malagasy tales suggest that they may have migrated there much earlier and lived alongside horned crocodiles…