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Crocodylian
Crocodilia () is an 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 true crocodiles (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 sides, with their eyes, ears, and nostril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mekosuchinae
Mekosuchinae is an extinct clade of crocodilians from the Cenozoic of Australasia. They represented the dominant group of crocodilians in the region during most of the Cenozoic, first appearing in the fossil record in the Eocene of Australia, and surviving until the arrival of humans: the Late Pleistocene on the Australian continent and during the Holocene in the Pacific islands of Fiji, New Caledonia and Vanuatu. Mekosuchine crocodiles are a diverse group displaying a great variety of shapes and sizes. Some taxa, like ''Baru'' and ''Paludirex'', were large semi-aquatic ambush hunters, though the two genera likely differed significantly in their hunting methods. The medium-sized ''Australosuchus'' may have been relatively cold-resistant and taxa like ''Trilophosuchus'' and ''Mekosuchus'' are renowned for their small size. One of the most distinct mekosuchines was ''Quinkana'', with its altirostral (deep) skull and blade-like serrated teeth. There is some question around the lifest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gavialoidea
Gavialoidea is one of three superfamily (zoology), superfamilies of crocodylians, the other two being Alligatoroidea and Crocodyloidea. Although many extinct species are known, only the gharial ''Gavialis gangeticus'' and the false gharial ''Tomistoma schlegelii'' are alive today, with ''Hanyusuchus'' having become extinct in the last few centuries. Extinct South American gavialoids likely Dispersal (ecology), dispersed in the mid Tertiary period, Tertiary from Africa and Asia. Fossil remains of the Puerto Rican gavialoid ''Aktiogavialis puertorisensis'' were discovered in a cave located in San Sebastián, Puerto Rico and dated to the Oligocene. This individual is thought to have crossed the Atlantic coming from Africa, indicating that this species was able to withstand saltwater. Classification Gavialoidea is Cladistics, cladistically defined as ''Gavialis gangeticus'' (the gharial) and all crocodylians closer to it than to ''Alligator mississippiensis'' (the American alligator) ... [...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] |
Gavialidae
Gavialidae is a family of large semiaquatic crocodilians with elongated, narrow snouts. Gavialidae consists of two living species, the gharial (''Gavialis gangeticus'') and the false gharial (''Tomistoma schlegelii''), both occurring in Asia. Many extinct members are known from a broader range, including the recently extinct '' Hanyusuchus''. Gavialids are generally regarded as lacking the jaw strength to capture the large mammalian prey favoured by crocodiles and alligators of similar size so their thin snout is best used to catch fish, however the false gharial has been found to have a generalist diet with mature adults preying upon larger vertebrates, such as ungulates. Taxonomy The family Gavialidae was proposed by Arthur Adams in 1854 for reptiles with a very long and slender muzzle, webbed feet and nearly equal teeth. It is currently recognized as a crown group, meaning that it only includes the last common ancestor of all extant (living) gavialids (the gharial and false g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prodiplocynodon
''Prodiplocynodon'' is an extinct genus of basal crocodyloid crocodylian. It is one of the only crocodyloids known from the Cretaceous and existed during the Maastrichtian stage. The only species of ''Prodiplocynodon'' is the type species ''P. langi'' from the Lance Formation of Wyoming, known only from a single holotype skull lacking the lower jaw. The skull was collected by the American Museum Expedition of 1892 from exposures near the Cheyenne River in Niobrara County. It was described by Charles C. Mook of the American Museum of Natural History in 1941. The generic name means "before ''Diplocynodon''" because Mook saw close similarities between the holotype skull and that of the alligatoroid '' Diplocynodon'' from the Eocene of Europe. Description Most of the cranial sutures that outline individual bones of the skull are not visible in the holotype, and are often obscured by cracks. However, the overall shape of ''Prodiplocynodon'' is similar to that of basal alligatoro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebecosuchia
Sebecosuchia (meaning "Sobek crocodiles") is an extinct group of mesoeucrocodylian crocodyliforms that includes the families Sebecidae and Baurusuchidae. The group was long thought to have first appeared in the Late Cretaceous with the baurusuchids, but '' Razanandrongobe'' pushes the origin of Sebecosuchia to the Middle Jurassic. The last surviving members of the group, the sebecids, appear to have lasted until the late Miocene or early Pliocene on the Greater Antilles. Fossils have been found primarily from South America but have also been found in Europe, North Africa, Madagascar, and the Indian subcontinent. History and phylogeny Sebecosuchia was first constructed in 1937 by George Gaylord Simpson. In 1946 the concept was again used by American paleontologist Edwin Colbert to include '' Sebecus'' and Baurusuchidae. ''Sebecus'', which had been known from South America since 1937, was an unusual crocodyliform with a deep snout and teeth that were ziphodont, or serrated and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodyloidea
Crocodyloidea is one of three superfamilies of crocodilians, the other two being Alligatoroidea and Gavialoidea, and it includes the crocodiles. Crocodyloidea may also include the extinct Mekosuchinae, native to Australasia from the Eocene to the Holocene, although this is disputed. Classification Cladistically, it is defined as ''Crocodylus niloticus'' (the Nile crocodile) and all crocodylians more closely related to ''C. niloticus'' than to either ''Alligator mississippiensis'' (the American alligator) or ''Gavialis gangeticus'' (the gharial). This is a stem-based definition for crocodiles, and is more inclusive than the crown group Crocodylidae. As a crown group, Crocodylidae only includes the last common ancestor of all extant (living) crocodiles and their descendants (living or extinct), whereas Crocodyloidea, as a stem group, also includes more basal extinct crocodile ancestors that are more closely related to living crocodiles than to alligators or gavialids. Whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planocraniidae
Planocraniidae is an extinct family of eusuchian crocodyliforms known from the Paleogene of Asia, Europe and North America. The family was coined by Li in 1976, and contains three genera, '' Boverisuchus'', '' Duerosuchus'' and '' Planocrania''. Planocraniids were highly specialized crocodyliforms that were adapted to living on land. They had extensive body armor, long legs, and blunt claws resembling hooves, and are sometimes informally called "hoofed crocodiles". Classification Prior to 2013, the term Pristichampsidae/Pristichampsinae was used for this group. However, the type specimen of '' Pristichampsus'' was found to be undiagnostic, and considered to be a ''nomen dubium''. As such, Brochu (2013) transferred the other species placed in ''Pristichampsus'' to '' Boverisuchus'', and resurrected Planocraniidae to replace Pristichampsidae/Pristichampsinae as the name for the clade. Brochu cladistically defined Planocraniidae as '' Planocrania hengdongensis'' and crocodyliform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Gharial
The gharial (''Gavialis gangeticus''), also known as gavial or fish-eating crocodile, is a crocodilian in the family (biology), family Gavialidae and among the longest of all living crocodilians. Mature females are long, and males . Adult males have a distinct boss at the end of the snout, which resembles an earthenware pot known as a ''ghara'', hence the name "gharial". The gharial is well adapted to catching fish because of its long, narrow snout and 110 sharp, interlocking teeth. The gharial probably evolved in the northern Indian subcontinent. Fossil gharial remains were excavated in Pliocene deposits in the Sivalik Hills and the Narmada River valley. It currently inhabits rivers in the plains of the northern part of the Indian subcontinent. It is the most thoroughly aquatic crocodilian, and leaves the water only for basking and building nests on moist sandbanks. Adults mate at the end of the cold season. Females congregate in spring to dig nests, in which they lay 20–95 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous–Paleogene Extinction Event
The Cretaceous–Paleogene (K–Pg) extinction event, also known as the K–T extinction, was the extinction event, mass extinction of three-quarters of the plant and animal species on Earth approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than also became extinct, with the exception of some ectothermic species such as sea turtles and crocodilians. It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the current era, the Cenozoic. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the Cretaceous–Paleogene boundary, K–Pg boundary or K–T boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows unusually high levels of the metal iridium, which is more common in asteroids than in the Earth's crust. As originally proposed in 1980 by a team of scientists le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptile
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocephalia. About 12,000 living species of reptiles are listed in the Reptile Database. The study of the traditional reptile orders, customarily in combination with the study of modern amphibians, is called herpetology. Reptiles have been subject to several conflicting Taxonomy, taxonomic definitions. In Linnaean taxonomy, reptiles are gathered together under the Class (biology), class Reptilia ( ), which corresponds to common usage. Modern Cladistics, cladistic taxonomy regards that group as Paraphyly, paraphyletic, since Genetics, genetic and Paleontology, paleontological evidence has determined that birds (class Aves), as members of Dinosauria, are more closely related to living crocodilians than to other reptiles, and are thus nested among re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
