sinensis in the Yangtze River, China, which grows to an average of 5 ft (1.5 m). Their name derives from the Spanish el lagarto, which means "the lizard". Caimans In Central and South America, the alligator family is represented by six species of the subfamily Caimaninae, which differ from the alligator by the absence of a bony septum between the nostrils, and having ventral armour composed of overlapping bony scutes, each of which is formed of two parts united by a suture. Besides the three species in Caiman, the smooth-fronted caimans in genus Paleosuchus and the black caiman in Melanosuchus are described. Caimans tend to be more agile and crocodile-like in their movements, and have longer, sharper teeth than alligators. C. crocodilus, the spectacled caiman, has the widest distribution, from southern Mexico to the northern half of Argentina, and grows to a modest size of about . The largest is the near-threatened Melanosuchus niger, the jacaré-açu or large or black caiman of the Amazon River basin. Black caimans grow to , with the unverified size of up to . The black caiman and American alligator are the only members of the alligator family that pose the same danger to humans as the larger species of the crocodile family. Although caimans have not been studied in depth, scientists have learned their mating cycles (previously thought to be spontaneous or year-round) are linked to the rainfall cycles and the river levels, which increases chances of survival for their offspring. Taxonomy † = extinct Family Alligatoridae Subfamily Alligatorinae Genus Alligator † Alligator hailensis † Alligator mcgrewi † Alligator mefferdi Alligator mississippiensis, American alligator † Alligator olseni † Alligator prenasalis Alligator sinensis, Chinese alligator † Alligator thomsoni Genus † Allognathosuchus Genus † Arambourgia Genus † Ceratosuchus Genus † Chrysochampsa Genus † Eoalligator Genus † Hassiacosuchus Genus † Krabisuchus Genus † Navajosuchus? Genus † Procaimanoidea Genus † Wannaganosuchus Subfamily Caimaninae Genus † Acresuchus Genus † Bottosaurus Genus Caiman † Caiman brevirostris Caiman crocodilus, Spectacled caiman Caiman latirostris, Broad-snouted caiman † Caiman lutescans † Caiman venezuelensis † Caiman wannlangstoni Caiman yacare, Yacare caiman Genus † Centenariosuchus Genus † Chinatichampsus Genus † Culebrasuchus Genus † Eocaiman Genus † Globidentosuchus Genus † Gnatusuchus Genus † Kuttanacaiman Genus Melanosuchus † Melanosuchus fisheri Melanosuchus niger, Black caiman Genus † Mourasuchus Genus † Necrosuchus Genus † Orthogenysuchus Genus Paleosuchus Paleosuchus palpebrosus, Cuvier's dwarf caiman Paleosuchus trigonatus, Smooth-fronted caiman Genus † Protocaiman