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Orthogenysuchus
''Orthogenysuchus'' is an extinct genus of caimanine alligatorids. Fossils have been found from the Wasatch Beds of the Willwood Formation of Wyoming, deposited during the early Eocene. The type species is ''O. olseni''. The holotype, known as AMNH 5178, is the only known specimen belonging to the genus and consists of a skull lacking the lower jaws. The braincase is filled in by the matrix and most of the suture lines between bones are indiscernible, making comparisons with other eusuchian material difficult. Phylogeny ''Orthogenysuchus'' was first named in 1924 by Charles C. Mook and was referred to as a eusuchian, although not to any particular eusuchian group known at the time. Later publications assigned the genus to the Crocodylidae, but more recent analyses propose that it is a pristichampsid or even a synonym of ''Pristichampsus''. In 1999, ''Orthogenysuchus'' was placed within a new clade containing the Miocene caimanines '' Purussaurus'' and ''Mourasuchus''. ''Orthog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mourasuchus
''Mourasuchus'' is an extinct genus of giant, aberrant caiman from the Miocene of South America. Its skull has been described as duck-like, being broad, flat, and very elongate, superficially resembling ''Stomatosuchus'' from the Late Cretaceous. History of Discovery ''Mourasuchus'' was first described by Price in 1964 based on a strange and nearly complete skull from the Solimões Formation of Amazonian Brazil, calling it ''Mourasuchus amazoniensis''. Unaware of Price's discovery, Langston described ''"Nettosuchus" atopus'' ("Absurd Duck Crocodile") only a year later based on fragmentary cranial, mandibular and postcranial remains from the middle Miocene La Venta Lagerstätte, a part of the Honda Group. Although he did recognize its similarities to caimans and alligators, Langston reasoned that its bizarre anatomy warranted its own monotypic family, naming it Nettosuchidae.Langston, W. (1965). ''Fossil crocodilians from Colombia and the Cenozoic history of the Crocodilia in So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willwood Formation
The Willwood Formation is a sedimentary sequence deposited during the late Paleocene to early Eocene, or Clarkforkian, Wasatchian and Bridgerian in the North American land mammal age, NALMA classification.Willwood Formation at Fossilworks.orgNeasham & Vondra, 1972 Description It consists of fine grained clastic rocks (mudstone and shale) interbedded with medium grained clastic rocks (sandstone) and sporadic Conglomerate (geology), conglomerates. The formation underlies portions of the Bighorn Basin of Big Horn County, Wyoming, Big Horn, Hot Springs County, Wyoming, Hot Springs, Park County, Wyoming, Park and Washakie County, Wyoming, Washakie counties of Wyoming. Dating ...
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Caimaninae
A caiman (also cayman as a variant spelling) is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans inhabit Mexico, Central and South America from marshes and swamps to mangrove rivers and lakes. 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 1,000 kg (2,200 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 average length for most o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatoridae
The 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 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 (living) alligators, caimans, and their descendants (living or extinct), whereas Alligatoroidea, as a stem-based group, also includes more basal extinct alligator ancestors that are more closely related to living alligators than to crocodiles or gavialids. When considering only living taxa (neontology), this makes Alligatoroidea and Alligatoridae redundant. The simplified cladogram below shows Alligatoridae's relationships to other extant (living) crocodilians. The below detailed cladogram show ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Eocene
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group (French: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphisbaenia
Amphisbaenia (called amphisbaenians or worm lizards) is a group of usually legless squamates, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As many species have a pink body and scales arranged in rings, they have a superficial resemblance to earthworms. While the genus '' Bipes'' retains forelimbs, all other genera are limbless. Although superficially similar to the snakes and blind lizards, recent phylogenetic studies suggest that they are most closely related to wall lizards of the family Lacertidae. Amphisbaenians are widely distributed, occurring in North America, Europe, Africa, South America, Western Asia and the Caribbean. Most species are less than long. Description 200px, left, Close-up of the head of'' Rhineura'' Despite a superficial resemblance to some primitive snakes, amphisbaenians have many unique features that distinguish them from other reptiles. Internally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emydidae
Emydidae (Latin ''emys'' (freshwater tortoise) + Ancient Greek εἶδος (''eîdos'', “appearance, resemblance”)) is a family of testudines (turtles) that includes close to 50 species in 10 genera. Members of this family are commonly called terrapins, pond turtles, or marsh turtles. Several species of Asian box turtles were formerly classified in the family; however, revised taxonomy has separated them to a different family (Geoemydidae). As currently defined, the Emydidae are entirely a Western Hemisphere family, with the exception of two species of pond turtle. Description The upper shell (carapace) of most emydids is the shape of a low arch, although in some species, it is domed. The upper shell may have one or two ridges that run from front to the back of the animal (a projection commonly called a "keel"), or such a feature may be absent. A prominent bridge often connects the top shell to the bottom shell ( plastron). Emydids have large bottom shells, and some memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tortoise
Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a turtle shell, shell to protect from predation and other threats. The shell in tortoises is generally hard, and like other members of the suborder Cryptodira, they retract their necks and heads directly backward into the shell to protect them. Tortoises can vary in size with some species, such as the Galápagos tortoise, Galápagos giant tortoise, growing to more than in length, whereas others like the Chersobius signatus, Speckled cape tortoise have shells that measure only long. Several lineages of tortoises Giant tortoise, have independently evolved very large body sizes in excess of 100 kg, including the Galápagos tortoise, Galapagos giant tortoise and the Aldabra giant tortoise. They are usually Diurnality, diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhineuridae
Rhineuridae is a family of amphisbaenians (commonly called worm lizards) that includes one living genus and species, ''Rhineura floridana'', as well as many extinct species belonging to both ''Rhineura'' and several extinct genera. The living ''R. floridana'' is found only in Georgia and Florida, but extinct species ranged across North America, some occurring as far west as Oregon. The family has a fossil record stretching back 60 million years to the Paleocene and was most diverse in the continental interior during the Eocene and Oligocene. Fossil record The fossil record of the Rhineuridae extends back almost to the Mesozoic, with the oldest rhineurid, '' Plesiorhineura tsentasai'', occurring in the Early Paleocene. ''Plesiorhineura'' is only known from a partial jaw, but it shares many features with modern rhineurids. Eocene rhineurids, such as ''Spathorhynchus fossorium'', are remarkably similar to the modern ''Rhineura'', suggesting very conservative evolution within the fami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choristodera
Choristodera (from the Greek χωριστός ''chōristos'' + δέρη ''dérē'', 'separated neck') is an extinct order of semiaquatic diapsid reptiles that ranged from the Middle Jurassic, or possibly Triassic, to the late Miocene (168 to 11.6 million years ago). Choristoderes are morphologically diverse, with the best known members being the crocodile-like neochoristoderes such as ''Champsosaurus''. Other choristoderans had lizard-like or long necked morphologies. Choristoderes appear to have been confined to the Northern Hemisphere, having been found in North America, Asia, and Europe, and possibly also North Africa. Choristoderes are generally thought to be derived neodiapsids that are close relatives or members of Sauria. History of Discovery Choristodera was erected in 1876, originally as a suborder of Rhynchocephalia by Edward Drinker Cope to contain ''Champsosaurus,'' which was described from Late Cretaceous strata of Montana by Cope in the same paper. A year late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarkforkian
The Clarkforkian North American Stage, on the geologic timescale, is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 56,800,000 to 55,400,000 years BP lasting . Considered to be within the Paleocene, more specifically the Late Paleocene, the Clarkforkian shares its upper boundary with the Thanetian. The Clarkforkian is preceded by the Tiffanian and followed by the Wasatchian NALMA stages. Substages It is considered to contain the following substages: *Cf3: (shares the upper boundary) and lower boundary source of the base of Clarkforkian (approximate) and upper boundary source of the base of the Ypresian (approximate). *Cf2: Is the lower boundary source of the base of the Clarkforkian (approximate) *Cf1: Upper boundary source of the base of the Ypresian (approximate) Fauna Notable mammals Multituberculata - non-therian mammals * '' Ectypodus'', neoplagiaulacid multituberculate Metatheria - marsupi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
