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Arvinachelys
''Arvinachelys goldeni'' is an extinct baenid turtle from the Late Cretaceous of Utah. ''A. goldeni'' is notable among turtles for the presence of two nasal openings instead of one, giving it a vaguely pig-nosed appearance in life. Description The holotype, UMNH VP 21151, is a largely completed skeleton, including the shell and skull, belonging to an animal about 60 centimeters long. Remains previously ascribed to other baenid turtles are now recognised to belong to the animal. Phylogenetics ''Arvinachelys'' bears most of the synapomorphies characteristic of Baenidae. It is described as a sister taxon to '' Hayemys''; given the latter's position as a lazarus taxon basal to the rest of Baenidae, ''Arvinachelys''' discovery extends its branch of the family tree back into the Campanian. However, ''Arvinachelys''' discovery may indicate that a reevaluation of Baenidae as a whole is necessary, as several remains from the region have been reassigned to this genus. Biology ''Arvina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baenidae
Baenidae is an extinct family of paracryptodiran turtles known from the Early Cretaceous to Eocene of North America. While during the Early Cretaceous they are found across North America, during the Late Cretaceous they are only found in Laramidia, having disappeared from Appalachia. The majority of lineages survived the K-Pg Extinction, but the family was extinct by the latest Eocene. The name of the type genus, ''Baena,'' appears to be of Native American origin. They are primarily found in freshwater deposits, and are considered to be aquatic, with a largely generalist habit. Genera * †'' Arundelemys'' * †'' Arvinachelys'' * †'' Baena'' * †''Cedrobaena'' * †''Chisternon'' * †'' Edowa'' * †''Gamerabaena'' * †'' Hayemys'' * †'' Lakotemys'' Lakota Formation, Berriasian-Valanginian * †''Neurankylus'' * †'' Palatobaena'' * †'' Peckemys'' * †''Plesiobaena ''Plesiobaena'' is an extinct genus of turtle which existed in the Belly River Formation, Canada duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baenidae
Baenidae is an extinct family of paracryptodiran turtles known from the Early Cretaceous to Eocene of North America. While during the Early Cretaceous they are found across North America, during the Late Cretaceous they are only found in Laramidia, having disappeared from Appalachia. The majority of lineages survived the K-Pg Extinction, but the family was extinct by the latest Eocene. The name of the type genus, ''Baena,'' appears to be of Native American origin. They are primarily found in freshwater deposits, and are considered to be aquatic, with a largely generalist habit. Genera * †'' Arundelemys'' * †'' Arvinachelys'' * †'' Baena'' * †''Cedrobaena'' * †''Chisternon'' * †'' Edowa'' * †''Gamerabaena'' * †'' Hayemys'' * †'' Lakotemys'' Lakota Formation, Berriasian-Valanginian * †''Neurankylus'' * †'' Palatobaena'' * †'' Peckemys'' * †''Plesiobaena ''Plesiobaena'' is an extinct genus of turtle which existed in the Belly River Formation, Canada duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaiparowits Formation
The Kaiparowits Formation is a sedimentary rock formation found in the Kaiparowits Plateau in Grand Staircase–Escalante National Monument, in the southern part of Utah in the western United States. It is over 2800 feet (850 m) thick, and is Campanian in age. This Upper Cretaceous formation was formed from alluvial floodplains of large rivers in coastal southern Laramidia; sandstone beds are the deposit of rivers, and mudstone beds represent floodplain deposits. It is fossiliferous, with most specimens from the lower half of the formation, but exploration is only comparatively recent, with most work being done since 1982. It has been estimated that less than 10% of the Kaiparowits formation has been explored for fossils. Most fieldwork has been conducted by The Natural History Museum of Utah. Age Traditionally, the Kaiparowits Formation has been considered to be roughly equivalent in age to the northern Dinosaur Park Formation. This, combined with the differences in fauna betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...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] |
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its west by Nevada. Utah also touches a corner of New Mexico in the southeast. Of the fifty U.S. states, Utah is the 13th-largest by area; with a population over three million, it is the 30th-most-populous and 11th-least-densely populated. Urban development is mostly concentrated in two areas: the Wasatch Front in the north-central part of the state, which is home to roughly two-thirds of the population and includes the capital city, Salt Lake City; and Washington County in the southwest, with more than 180,000 residents. Most of the western half of Utah lies in the Great Basin. Utah has been inhabited for thousands of years by various indigenous groups such as the ancient Puebloans, Navajo and Ute. The Spanish were the first Europe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lazarus Taxon
In paleontology, a Lazarus taxon (plural ''taxa'') is a taxon that disappears for one or more periods from the fossil record, only to appear again later. Likewise in conservation biology and ecology, it can refer to species or populations that were thought to be extinct, and are rediscovered. The term Lazarus taxon was coined by Karl W. Flessa & David Jablonski in 1983 and was then expanded by Jablonski in 1986. Paul Wignall and Michael Benton defined Lazarus taxa as, "At times of biotic crisis many taxa go extinct, but others only temporarily disappeared from the fossil record, often for intervals measured in millions of years, before reappearing unchanged". Earlier work also supports the concept though without using the name Lazarus taxon, like work by Christopher R. C. Paul. The term refers to the story in the Christian biblical Gospel of John, in which Jesus Christ raised Lazarus from the dead. Potential explanations Lazarus taxa are observational artifacts that app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrop near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic column wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaurs
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species, are among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teratophoneus
''Teratophoneus'' ("monstrous murderer"; Greek: ''teras'', "monster" and ''phoneus'', "murderer") is a genus of tyrannosaurid dinosaur which lived during the late Cretaceous period (late Campanian age, about 77 to 76 million years ago) in what is now Utah, United States, containing a single known species, ''T. curriei''. It is known from an incomplete skull and postcranial skeleton recovered from the Kaiparowits Formation. It was specifically named ''T. curriei'' in honor of Philip J. Currie. Discovery and naming Fossils of ''Teratophoneus'' were first found in the Kaiparowits Formation of southern Utah. Later, fossils from the same formation were discovered and identified as the genus. Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late Cretaceous period. This date means that ''Teratophoneus'' lived in the middle of the Campanian stage of the Late Cretaceous. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasaurolophus
''Parasaurolophus'' (; meaning "near crested lizard" in reference to '' Saurolophus)'' is a genus of herbivorous hadrosaurid ornithopod dinosaur that lived in what is now North America and possibly Asia during the Late Cretaceous Period, about 76.5–73 million years ago. It was a herbivore that walked both as a biped and as a quadruped. Three species are universally recognized: ''P. walkeri'' (the type species), ''P. tubicen'', and the short-crested ''P. cyrtocristatus''. Additionally, a fourth species, ''P. jiayinensis'', has been proposed, although it is more commonly placed in the separate genus ''Charonosaurus''. Remains are known from Alberta (Canada), New Mexico and Utah (United States), and possibly Heilongjiang (China). The genus was first described in 1922 by William Parks from a skull and partial skeleton found in Alberta. ''Parasaurolophus'' was a hadrosaurid, part of a diverse family of Cretaceous dinosaurs known for their range of bizarre head adornments wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
