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Alligatoridae
The family (biology), family Alligatoridae of crocodylians includes alligators, caimans and their extinct relatives. Phylogeny The superfamily Alligatoroidea includes all crocodilians (fossil and extant) that are more closely related to the American alligator than to either the Nile crocodile or the gharial. This is a stem-based taxon, stem-based definition for alligators, and is more inclusive than the crown group Alligatoridae. As a crown group, Alligatoridae only includes the last common ancestor of all extant taxon, extant (living) alligators, caimans, and their descendants (living or extinct), whereas Alligatoroidea, as a stem-based group, also includes more basal (phylogenetics), basal extinct alligator ancestors that are more closely related to living alligators than to crocodiles or gavialids. When considering only living taxa (neontology), Alligatoroidea and Alligatoridae contain the same species. The simplified cladogram below shows Alligatoridae's relationships to o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatoroidea
Alligatoroidea is one of three superfamilies of crocodylians, the other two being Crocodyloidea and Gavialoidea. Alligatoroidea evolved in the Late Cretaceous period, and consists of the alligators and caimans, as well as extinct members more closely related to the alligators than the two other groups. Evolution The superfamily Alligatoroidea is thought to have split from the crocodile-gharial lineage in the late Cretaceous, about 80 million years ago, but possibly as early as 100 million years ago based on molecular phylogenetics. '' Leidyosuchus'' of Alberta is the earliest known genus. Although, a 2025 study considers it and Deinosuchus to be non-crocodylian eusuchians closely related to crocodylians. Fossil alligatoroids have been found throughout Eurasia as land bridges across both the North Atlantic and the Bering Strait have connected North America to Eurasia during the Cretaceous, Paleogene, and Neogene periods. Alligators and caimans split in North America dur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodylia
Crocodilia () is an Order (biology), order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchian, a subset of archosaurs that appeared about 235 million years ago and were the only survivors of the Triassic–Jurassic extinction event. While other crocodylomorph groups further survived the Cretaceous–Paleogene extinction event, notably sebecosuchians, only the crocodilians have survived into the Quaternary. The order includes the crocodile, true crocodiles (Family (biology), family Crocodylidae), the alligators and caimans (family Alligatoridae), and the gharial and false gharial (family Gavialidae). Although the term "crocodiles" is sometimes used to refer to all of these families, the term "crocodilians" is less ambiguous. Extant crocodilians have flat heads with long snouts and tails that are compressed on the si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligators
An alligator, or colloquially gator, is a large reptile in the genus ''Alligator'' of the family Alligatoridae in the order Crocodilia. The two extant species are the American alligator (''A. mississippiensis'') and the Chinese alligator (''A. sinensis''). Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the late Eocene epoch about 37 million years ago. The term "alligator" is likely an anglicized form of ', Spanish for "the lizard", which early Spanish explorers and settlers in Florida called the alligator. Early English spellings of the name included ''allagarta'' and ''alagarto''. Evolution Alligators and caimans split in North America during the early Tertiary or late Cretaceous (about 53 million to 65 million years ago). The Chinese alligator split from the American alligator about 33 million years ago and probably descended from a lineage that crossed the Bering land bridge during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caimaninae
A caiman ( (also spelled cayman) from Taíno ''kaiman'') is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans are native to Central and South America and inhabit marshes, swamps, lakes, and mangrove rivers. They have scaly skin and live a fairly nocturnal existence. They are relatively small-sized crocodilians with an average maximum weight of depending on species, with the exception of the black caiman (''Melanosuchus niger''), which can grow more than in length and weigh in excess of 450 kg (1,000 Ib). The black caiman is the largest caiman species in the world and is found in the slow-moving rivers and lakes that surround the Amazon basin. The smallest species is the Cuvier's dwarf caiman (''Paleosuchus palpebrosus''), which grows to long. There are six different species of caiman found throughout the watery jungle habitats of Central and Southern America. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globidonta
Globidonta is a clade of alligatoroids that includes alligators, caimans, and closely related extinct forms. It is defined as a Stem-based taxon, stem-based clade including ''Alligator mississippiensis'' (the American Alligator) and all forms more closely related to it than to ''Diplocynodon''. The group's fossil range extends back into the Campanian stage of the Late Cretaceous with early alligatoroids such as ''Albertochampsa'' and ''Brachychampsa''. Extinct globidontans were particularly common in North America and Eurasia, and their modern range also includes South America. Basal globidontans are characterized by their blunt snouts and bulbous teeth. Modern globidontans have flattened snouts and more conical teeth, and are seen as more generalized than earlier globidontans. Generalized forms are usually expected to be ancestral to more specialized forms rather than descendants of them, so it is unusual for basal members of the group to appear specialized. This seems to conflic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
