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Naomichelys
''Naomichelys'' is an extinct genus of helochelydrid stem turtle known from the Cretaceous (Aptian-Campanian) of North America. It is the only member of the family known to be native to North America. Distribution ''Naomichelys'' is known numerous remains from western North America, most notably the holotype partial shell from the Cloverly Formation of Montana and a complete skeleton from the Antlers Formation of Texas. Indetermiate remains are known extending up to the Campanian in the United States and Canada. It is the only known North American member of Helochelydridae.W. G. Joyce, J. Sterli, and S. D. Chapman. 2014. The skeletal morphology of the solemydid turtle Naomichelys speciosa from the Early Cretaceous of Texas. Journal of Paleontology 88(6):1257-1287 Location After * Kootenai Formation, Montana, Early Cretaceous (Aptian) * Arundel Formation, Maryland, Aptian * Cloverly Formation, Montana and Wyoming, Aptian * Trinity Group, Texas, Aptian-Albian * Willow Tan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helochelydridae
The Helochelydridae are an extinct family of stem-turtles known from fossils found in North America and Europe spanning the Early to Late Cretaceous. Description The skull, shell and osteoderms of helochelydrids are covered in small, cylindrical protuberances, which are a distinctive characteristic of the group. They are thought to be terrestrial, based on the presence of limb osteoderms and bone histology. Their skull morphology is dissimilar to that of extant tortoises, suggesting an omnivorous habit similar to that of box turtles. Taxonomy Helochelydridae includes all turtles that closely related to '' Helochelydra'' than '' Sichuanchelys'', '' Meiolania'', or extant turtles. Although referred to as Solemydidae in recent literature on extinct turtles, Helochelydridae has priority over Solemydidae. They are placed as part of the clade Perichelydia. Some recent studies have recovered them as paracryptodires, though other studies have found them to be more basal than parac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cedar Mountain Formation
The Cedar Mountain Formation is the name given to a distinctive sedimentary geologic formation in eastern Utah, spanning most of the early and mid-Cretaceous. The formation was named for Cedar Mountain (Utah), Cedar Mountain in northern Emery County, Utah, where William Lee Stokes first studied the exposures in 1944. Geology The formation occurs between the underlying Morrison Formation and overlying Naturita Formation (sometimes formerly called the Dakota Formation). It is composed of non-marine sediments, that is, sediments deposited in rivers, lakes and on flood plains. Based on various fossils and radiometric dating, radiometric dates, the Cedar Mountain Formation was deposited during the last half of the Early Cretaceous Epoch, about 127 - 98 million years ago (mya). It has lithography similar to the Burro Canyon Formation in the region. Dinosaur fossils occur throughout the formation, but their study has only occurred since the early 1990s. The dinosaurs in the lower part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloverly Formation
The Cloverly Formation is a geological formation of Early and Late Cretaceous age (Valanginian to Cenomanian stage) that is present in parts of Montana, Wyoming, Colorado and Utah in the western United States. It was named for a post office on the eastern side of the Bighorn Basin in Wyoming by N.H. Darton in 1904. The sedimentary rocks of formation were deposited in floodplain environments and contain vertebrate fossils, including a diverse assemblage of dinosaur remains. In 1973, the Cloverly Formation Site was designated as a National Natural Landmark by the National Park Service. Stratigraphy The Cloverly Formation rests disconformably on the Morrison Formation and is conformably overlain by the Thermopolis Shale. It is subdivided into a variety of members, depending on the location.Moberly, R.M., Jr., 1960, Morrison, Cloverly, and Sykes Mountain formations, northern Bighorn basin, Wyoming and Montana: Geological Society of America Bulletin, v. 71, no. 8, p. 1137-1176. In t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antlers Formation
The Antlers Formation is a stratum which ranges from Arkansas through southern Oklahoma into northeastern Texas. The stratum is thick consisting of silty to sandy mudstone and fine to coarse grained sandstone that is poorly to moderately sorted. The stratum is cemented with clay and calcium carbonate. In places the sandstone may be conglomeratic or ferruginous (rich in iron oxides). Based on correlation with the Trinity Group of Texas, the Antlers Formation is estimated to be late Aptian-early Albian. This age range is supported by the presence of two dinosaurs that are also known from the Cloverly Formation, ''Deinonychus'' and ''Tenontosaurus''. Amphibians Indeterminate frog remains. Possible indeterminate salamander remains. Fish References: Cifelli ''et al.'' 1999; Wedel ''et al.'' 2000, Kielan-Jarorowska and Cifelli 2001; Nydam and Cifelli 2002. Cartilaginous fish Ray-finned fish Possible indeterminate amid remains. Possible indeterminate lepisosteid remains. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Straight Cliffs Formation
The Straight Cliffs Formation is a stratigraphic unit in the Kaiparowits Plateau of south central Utah. It is Late Cretaceous (latest Turonian – early Campanian) in age and contains fluvial (river systems), paralic (swamps and lagoons), and marginal marine (shoreline) siliciclastic strata. It is well exposed around the margin of the Kaiparowits Plateau in the Grand Staircase – Escalante National Monument in south central Utah. The formation is named after the Straight Cliffs, a long band of cliffs creating the topographic feature Fiftymile Mountain. The Straight Cliffs Formation was deposited in a marginal marine basin system along the western edge of the Cretaceous Western Interior Seaway. It is bounded below by the Tropic Shale and above by the Wahweap Formation. A variety of fossil species have been found within the Straight Cliffs including ammonites, mollusks, foraminifera, ostracods, sharks, fish, amphibians, turtles, lizards, crocodyliforms, dinosaurs, and mammals. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willow Tank Formation
The Willow Tank Formation is a geologic formation which outcrops in the U.S. state of Nevada. Initially believed to be of Early Cretaceous ( Albian) age, later studies have concluded that it was more likely to be of Late Cretaceous (Cenomanian) age, making it equivalent to the Cloverly and Cedar Mountain Formations. It was deposited in an anastomosed fluvial system. Paleofauna All paleofauna listed are taken from a list compiled by Bonde (2008a) unless stated otherwise. Non-dinosaurs * '' cf. Adocus'' * ''Baena'' sp. * ''Ceratodus'' sp. * Coprolites (indet.) * Crocodyliformes indet. * Gastropoda indet. * Holostei indet. * Lepisosteidae indet. * ''Naomichelys'' sp. * ''Scoyenia sp. * Trionychidae (?) indet. Dinosaurs * Dromaeosauridae indet. * Iguanodontia indet. * '' Macroelongatoolithus carlylei'' * '' Nevadadromeus schmitti'' * Ornithopoda indet. * Theropoda indet. * Titanosauriformes indet. * Thyreophora indet. * Tyrannosauroidea Tyrannosauroidea (me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropic Shale
The Tropic Shale is a Mesozoic geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation,Weishampel, ''et al.'' (2004). "Dinosaur distribution." Pp. 517-607. including '' Nothronychus graffami''. The Tropic Shale is a stratigraphic unit of the Kaiparowits Plateau of south central Utah. The Tropic Shale was first named in 1931 after the town of Tropic where the Type section is located. The Tropic Shale outcrops in Kane and Garfield counties, with large sections of exposure found in the Grand Staircase–Escalante National Monument. Geology The Tropic Shale is predominantly marine mudstone and claystone, with several radioisotopically-dated bentonite marker beds, and occasional sandstone layers deposited during the late Cretaceous Period during the Upper Cenomanian through the Middle Turonian (95-92 Ma). The Tropic Shale has an average thickness range from 183–274 m. The Tropic Shale conformity overlies the Dakota Formation and un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous Turtles
{{disambiguation, geo ...
Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early Branch, a stream in Missouri * Early County, Georgia Other uses * ''Early'' (Scritti Politti album), 2005 * ''Early'' (A Certain Ratio album), 2002 * Early (name) * Early effect, an effect in transistor physics * Early Records, a record label * the early part of the morning See also * Earley (other) Earley is a town in England. Earley may also refer to: * Earley (surname), a list of people with the surname Earley * Earley (given name), a variant of the given name Earlene * Earley Lake, a lake in Minnesota *Earley parser, an algorithm *Earley ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1908
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood Petrified wood, also known as petrified tree (from Ancient Greek meaning 'rock' or 'stone'; literally 'wood turned into stone'), is the name given to a special type of ''fossilized wood'', the fossilized remains of terrestrial vegetation. ''P ... and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menefee Formation
The Menefee Formation is a lower Campanian geologic formation found in Colorado and New Mexico, United States. Description The Menefee Formation consists of fluvial sandstone, shale, and coal. Based on ammonite biostratigraphy, the age of the Menefee Formation can be constrained to 84.2-79 million years ( Ma), based on the presence of '' Baculites perplexus'' in the overlying Cliff House Sandstone The Cliff House Sandstone is a late Campanian stratigraphic unit comprising sandstones in the western United States. Description The Cliff House Sandstone consists of fine grained white to orange calcareous sandstone. It intertongues with the ..., and ammonites from the late Santonian in the underlying Point Lookout Sandstone. Named members include a lower Cleary Coal Member and an upper Allison Member. The Mesaverde Group in the San Juan Basin records a marine regression-Transgression (geology), transgression sequence of the western margin of the Western Interior Seaway. The Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wahweap Formation
The Wahweap Formation of the Grand Staircase–Escalante National Monument is a geological formation in southern Utah and northern Arizona, around the Lake Powell region, whose strata date back to the Late Cretaceous (Campanian stage). Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574–588. . Age The Wahweap formation is divided into four members, which are listed below with their respective ages: * Last Chance Creek Member: 82.17-81.55 Ma * Reynolds Point Member: 81.55-80.61 Ma * Coyote Point Member: 80.61-79 Ma * Pardner Canyon Member: 79-77.29 Ma Paleobiota Invertebrates The Wahweap Formation shows a substantial amount of invertebrate activity ranging from fossilized insect burrows in petrified logs to var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesaverde Formation
The Mesaverde Group is a Late Cretaceous stratigraphic group found in areas of Colorado, New Mexico, Utah, and Wyoming, in the Western United States. History The Mesaverde Formation was first described by W.H.Holmes in 1877 during the Hayden Survey. Holmes described the formation in the northern San Juan Basin as consisting of three units, which were a "Lower Escarpment" consisting of 40 m of ledge- and cliff-forming massive sandstone; a "Middle Coal Group" consisting of up to 300 m of thick slope-forming sandstone, shale, marl, and lignite; and an "Upper Escarpment" consisting of 60 m of ledge- and cliff-forming sandstone. A.J. Collier redesignated these units in 1919 as the Point Lookout Sandstone, the Menefee Formation, and the Cliff House Sandstone, and raised the Mesaverde Formation to group rank. The group was later traced to the greater Green River Basin, the Uintah and Piceance Basins, the Bighorn Basin, the Front Range, the Zuni Basin, the Wasatch Plateau, Wind Riv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
