The crocodiles or Crocodylidae are a family of reptiles with fourteen species. The term “crocodile” is also sometimes used in a broader sense to refer to the order Crocodylia (crocodilians). The true crocodiles (family Crocodylidae), the gaviais (family Gavialidae ) and the caymans , alligators and alligators (family Alligatoridae ).
Crocodiles live in the Americas , Africa , Asia and Australia . Most crocodiles live on the banks of rivers , while those in Australia and Pacific islands also frequent the sea. Crocodiles do not have natural predators because they are a top animal in the food chain.
The largest reptile on earth today is the saltwater crocodile found in northern Australia and the islands of the southeast of Asia .
Crocodiles, after birds , are the closest relatives of dinosaurs today. Both dinosaurs and crocodiles evolved from tecodonts , just as birds may have evolved from dinosaurs. Studies by the University of California at Santa Cruz show that crocodiles are closer phylogenetically to birds than to any other living reptile species, such as lizards and snakes, because they have the same common ancestor . years ago. This makes crocodiles more related to birds than to all other reptiles today. They appeared about 248 million years ago, having lived with dinosaurs . Although they do not have the same mobility as their ancestors, crocodiles have been recorded that can run along riverbanks at speeds of up to 16 km / h.