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Fort Crittenden Formation
The Fort Crittenden Formation is a geological Formation (geology), formation in Arizona whose strata date back to the Late Cretaceous. 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. 574–88. . Vertebrate paleofauna Amphibians Archosaurs Bony fishes Cartilaginous fishes Lepidosaurs Teiid and anguid lizards are known from the formation. Turtles See also * List of dinosaur-bearing rock formations Footnotes References * Sullivan, R.M., and Lucas, S.G. 2006.The Kirtlandian land-vertebrate "age" – faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America " ''New Mexico Museum of Natural History and Science, Bulletin'' 35:7� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bony Fishes
Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilage. The vast majority of fish are members of Osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species. It is the largest class of vertebrates in existence today. The group Osteichthyes is divided into the ray-finned fish (Actinopterygii) and lobe-finned fish (Sarcopterygii). The oldest known fossils of bony fish are about 425 million years old, which are also transitional fossils, showing a tooth pattern that is in between the tooth rows of sharks and bony fishes. Osteichthyes can be compared to Euteleostomi. In paleontology the terms are synonymous. In ichthyology the difference is that Euteleostomi presents a cladistic view which includes the terrestrial tet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Dinosaur-bearing Rock Formations
This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have been documented. Containing body fossils * List of stratigraphic units with dinosaur body fossils ** List of stratigraphic units with few dinosaur genera ** List of stratigraphic units with indeterminate dinosaur fossils Containing trace fossils * List of stratigraphic units with dinosaur trace fossils ** List of stratigraphic units with dinosaur tracks *** List of stratigraphic units with ornithischian tracks *** List of stratigraphic units with sauropodomorph tracks *** List of stratigraphic units with theropod tracks See also * Lists of fossiliferous stratigraphic units * List of fossil sites * Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ... {{DE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basilemys
''Basilemys'' () is a large, terrestrial trionychoid turtle from the Upper Cretaceous. In Greek, the word "Basil" means royal or kingly and the word "Emys" means turtle. Therefore, ''Basilemys'' means King Turtle. ''Basilemys'' has been found in rocks dating to the Campanian and Maastrichtian subdivisions of the Late Cretaceous and is considered to be the largest terrestrial turtle of its time. ''Basilemys'' has solely been found in North America. The family Nanhsiungchelyidae, which is the family ''Basilemys'' belongs to, made its first appearance in the Lower Cretaceous, in what we now call Asia. Because of ''Basilemys,'' we know that this family appeared in North America in the Upper Cretaceous. It is possible that ''Basilemys'' and other nanhsiungchelyids are immigrants from Asia. They might have arrived in North America by passing through what we now call the Bering Strait somewhere during the Cretaceous. In an analysis made by Sukhanov et al. on a new Nansiunghelyid turtle f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspideretes
''Nilssonia'' is a genus of softshell turtles (family Trionychidae) from rivers, streams, ponds, and lakes in South Asia and Burma. In many treatments, it is monotypic, with the single species Burmese peacock softshell (''N. formosa''). However, the supposed other genus of peacock softshells, ''Aspideretes'', is more closely related to ''N. formosa'' than had been believed. They differ only in the neural plates between the first pleural scale pair of the bony carapace, which are fused into one in ''N. formosa'' and unfused in the others. (2007). "Genetic evidence for wild-living ''Aspideretes nigricans'' and a molecular phylogeny of South Asian softshell turtles (Reptilia: Trionychidae: ''Aspideretes, Nilssonia'')". '' Zool. Scripta'' 36 (4): 301–310. (HTML abstract) Thus, it has been proposed to unite the two genera under the older name, ''Nilssonia''. As it seems, the closest living relatives of the Burmese peacock softshell are the Indian softshell turtle (''A./N. gangeticus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adocus
''Adocus'' is an extinct genus of aquatic turtles belonging to the family Adocidae. ''Adocus'' was once considered to belong to the family Dermatemyidae. Description Species of the genus ''Adocus'' had flattened and smoothly contoured shells with horny sculptured plates. The shells could reach a length of about 80 cm. These large freshwater turtles had an omnivorous diet. They lived from the Late Cretaceous to the Paleocene in North America, but in Asia, they were also present during the Oligocene. Distribution These turtles have been found in Cretaceous to Paleogene of Canada, United States, Mongolia, China, Japan, Kazakhstan, Tajikistan, and Uzbekistan. Species * ''Adocus agilis'' * ''Adocus aksary'' * '' Adocus beatus'', type species (synonyms: ''A. punctatus'', ''A. lacer'') * ''Adocus bossi'' * ''Adocus bostobensis'' * ''Adocus dzhurtasensis'' * ''Adocus firmus'' * ''Adocus foveatus'' * ''Adocus hesperius'' * ''Adocus kirtlandius'' * ''Adocus kizylkumensis'' * ''A ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myledaphus
''Myledaphus'' is a genus of Late Cretaceous cartilaginous fish whose fossils are known from Canada, the Midwest of the United States, Olmos Formation of the Difunta Group of Mexico, and the Beshtyubin and Bissekty Formations of Uzbekistan. It was a freshwater guitarfish that probably reached a length of , and had teeth adapted for a durophagous diet of animals such as clams. Most taxonomic authories place the genus in the Rhinobatidae. Two species are known: ''Myledaphus bipartitus'', the type species, and ''Myledaphus araucanus'', named in 2019. Fossils and age The most common remains of this fish are teeth and vertebra. A study performed on ''Myledaphus'' vertebra from Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ... in 2013 revealed that ''Myledaphus'' had an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartilaginous Fishe
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3.9 in) finless sleeper ray to the 10 m (32 ft) whale shark. The class is divided into two subclasses: Elasmobranchii (sharks, rays, skates, and sawfish) and Holocephali (chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class). Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates. Anatomy Skeleton The skeleton is cartilaginous. The notochord is gradually replaced by a vertebral column during development, except in Holocephali, where the notochord stays intact. In some deepwater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachyrhizodus
''Pachyrhizodus'' is an extinct genus of ray-finned fish that lived during the Cretaceous to Paleocene in what is now Europe, North America, South America, and Oceania. Many species are known, primarily from the Cretaceous of England and the midwestern United States. History and discovery ''Pachyrhizodus'' fossils were first collected from Cambridgeshire, England in the 1840s and were very fragmentary, only a partial maxilla (SMB.9097) and were described as a species of ''Raphiosaurus'' in 1842 by Richard Owen. The type remains of ''Pachyrhizodus'' consisted of a maxilla (BMNH 49014) from the Lower Cretaceous of Sussex, England and was originally thought to be a mandible that Louis Agassiz dubbed ''Pachyrhizodus'' in 1850,Dixon, F. (1850): Geology and Fossils of the Tertiary and Cretaceous Formations of Sussex. – 422 pp.; London (Longman, Brown, Green & Longmans). with Frederick Dixon creating the species name ''basalis'' for the specimen. Over the next few years, many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachyrhizodus Caninus Skeletons
''Pachyrhizodus'' is an extinct genus of ray-finned fish that lived during the Cretaceous to Paleocene in what is now Europe, North America, South America, and Oceania. Many species are known, primarily from the Cretaceous of England and the midwestern United States. History and discovery ''Pachyrhizodus'' fossils were first collected from Cambridgeshire, England in the 1840s and were very fragmentary, only a partial maxilla (SMB.9097) and were described as a species of ''Raphiosaurus'' in 1842 by Richard Owen. The type remains of ''Pachyrhizodus'' consisted of a maxilla (BMNH 49014) from the Lower Cretaceous of Sussex, England and was originally thought to be a mandible that Louis Agassiz dubbed ''Pachyrhizodus'' in 1850,Dixon, F. (1850): Geology and Fossils of the Tertiary and Cretaceous Formations of Sussex. – 422 pp.; London (Longman, Brown, Green & Longmans). with Frederick Dixon creating the species name ''basalis'' for the specimen. Over the next few years, many ''Pach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
