However, the full genome, published in 2014, suggests that the alligator evolved much more slowly than mammals and birds. The alligator's full mitochondrial genome was sequenced in the 1990s, and it suggests the animal evolved at a rate similar to mammals and greater than birds and most cold-blooded vertebrates. mississippiensis lineage has existed in North America for over 8 million years. This alligator and the American alligator are now considered to be sister taxa, meaning that the A. Unlike the other extinct alligator species of the same genus, the fossil skull was virtually indistinguishable from that of the modern American alligator. In 2016, a Miocene (about 23 to 5.3 Mya) fossil skull of an alligator was found at Marion County, Florida. Fossils identical to the existing American alligator are found throughout the Pleistocene, from 2.5 million to 11.7 thousand years ago. The Chinese alligator likely descended from a lineage that crossed the Bering land bridge during the Neogene. Fossil alligatoroids have been found throughout Eurasia, because bridges across both the North Atlantic and the Bering Strait connected North America to Eurasia about 66 to 23 Mya.Īlligators and caimans split in North America during the late Cretaceous, and the caimans reached South America by the Paleogene, before the closure of the Isthmus of Panama during the Neogene period, from about 23 to 2.58 Mya. Leidyosuchus of Alberta is the earliest known fossil, from the Campanian era 83 to 72 Mya. Members of this superfamily first arose in the late Cretaceous, about 100–65 million years ago (Mya). The superfamily Alligatoroidea includes all crocodilians (fossil and extant) that are more closely related to the American alligator than to either the Nile crocodile ( Crocodylus niloticus) or the gharial ( Gavialis gangeticus). They are grouped in the family Alligatoridae with the caimans. In 1807, Georges Cuvier created the genus Alligator the American alligator and the Chinese alligator are the only extant species in the genus. The American alligator was first classified by French zoologist François Marie Daudin as Crocodilus mississipiensis in 1801. The species is the official state reptile of three states: Florida, Louisiana, and Mississippi. Subsequent conservation efforts have allowed their numbers to increase and the species was removed from endangered status in 1987. Historically, hunting had decimated their population, and the American alligator was listed as an endangered species by the Endangered Species Act of 1973. The conservation status of the American alligator is listed as Least Concern by the International Union for Conservation of Nature. Young are born with yellow bands around their bodies and are protected by their mother for up to one year. Eggs are laid in a nest of vegetation, sticks, leaves, and mud in a sheltered spot in or near the water. Male American alligators use infrasound to attract females. Throughout the year (in particular during the breeding season), American alligators bellow to declare territory, and locate suitable mates. They play an important role as ecosystem engineers in wetland ecosystems through the creation of alligator holes, which provide both wet and dry habitats for other organisms. It is distinguished from the sympatric American crocodile by its broader snout, with overlapping jaws and darker coloration, and is less tolerant of saltwater but more tolerant of cooler climates than the American crocodile, which is found only in tropical and warm subtropical climates.Īmerican alligators are apex predators and consume fish, amphibians, reptiles, birds, and mammals. The American alligator inhabits subtropical and tropical freshwater wetlands, such as marshes and cypress swamps, from southern Texas to North Carolina. Females are smaller, measuring 2.6 to 3 m (8.5 to 9.8 ft) in length. It is one of the two extant species in the genus Alligator, and is larger than the only other living alligator species, the Chinese alligator.Īdult male American alligators measure 3.4 to 4.6 m (11.2 to 15.1 ft) in length, and can weigh up to 500 kg (1,100 lb), with unverified sizes of up to 5.84 m (19.2 ft) and weights of 1,000 kg (2,200 lb) making it the second largest member of the family Alligatoridae, after the black caiman. The American alligator ( Alligator mississippiensis), sometimes referred to colloquially as a gator or common alligator, is a large crocodilian reptile native to the Southeastern United States. Approximate range of American alligator in the United States
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