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Sloan Canyon Formation
The Sloan Canyon Formation is a late Triassic geologic formation exposed in northeastern New Mexico. Fossil theropod tracks have been reported from the formation. Description The Sloan Canyon Formation consists of variegated reddish-brown, purple, and green mudstones, with some beds of siltstone and marl. It rests on the Travesser Formation and is overlain by the Sheep Pen Sandstone. Total thickness is . The formation is usually assigned to the Dockum Group. The proposal of Spencer G. Lucas and his collaborators to abandon the Dockum Group, possibly in favor of the Chinle Group, is highly controversial. Fossils A phytosaur skull was found in the Sloan Canyon Formation in 1939, establishing that it was a Triassic formation. The formation is part of one of the largest continuously mapped Triassic vertebrate tracksites, with the earliest studied exposures at Peacock Canyon. Ichnofossils (track fossils) include the archosaurs '' Brachychirotherium'' and ''Chirotherium'', a po ... [...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 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 Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spencer G
Spencer may refer to: People *Spencer (surname) **Spencer family, British aristocratic family ** List of people with surname Spencer * Spencer (given name), a given name (including a list of people with the name) Places Australia *Spencer, New South Wales, on the Central Coast *Spencer Gulf, one of two inlets on the South Australian coast United States *Spencer, Idaho *Spencer, Indiana *Spencer, Iowa *Spencer, Massachusetts **Spencer (CDP), Massachusetts *Spencer, Missouri *Spencer, Nebraska *Spencer, New York **Spencer (village), New York *Spencer, North Carolina *Spencer, Ohio *Spencer, Oklahoma *Spencer, South Dakota *Spencer, Tennessee *Spencer, Virginia *Spencer, West Virginia *Spencer, Wisconsin **Spencer (town), Wisconsin *Spencer County, Indiana *Spencer County, Kentucky Ireland *Spencer Dock, North Wall, Dublin Arts and entertainment Fictional characters *Spencer, character in ''Beyblade'' *Spencer, character from ''Final Fantasy Mystic Quest'' * Spencer family (''G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Stratigraphic Units With Theropod Tracks
The following tables list the global geological sites where tracks of theropod dinosaurs have been found, together with the proper names of the rock formations (stratigraphic units) that contain them. Non-avian theropods Avialans See also *List of dinosaur-bearing rock formations *List of fossil sites This list of fossil sites is a worldwide list of localities known well for the presence of fossils. Some entries in this list are notable for a single, unique find, while others are notable for the large number of fossils found there. Many of t ... Footnotes References * Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. . {{DEFAULTSORT:List Of Stratigraphic Units With Theropod Tracks Theropod tracks Dinosaur trace fossils Prehistoric theropods ... [...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 Cretaceo ... {{DEFAULTSOR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic, Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period. It is centered in Wyoming and Colorado, with outcrops in Montana, North Dakota, South Dakota, Nebraska, Kansas, the panhandles of Oklahoma and Texas, New Mexico, Arizona, Utah, and Idaho. Equivalent rocks under different names are found in Canada. It covers an area of 1.5 million square kilometers (600,000 square miles), although only a tiny fraction is exposed and accessible to geologists and Paleontology, paleontologists. Over 75% is still buried under the prairie to the east, and much of its western paleogeographic extent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchosauroides
''Rhynchosauroides'' is an ichnogenus, a form taxon based on footprints. The organism producing the footprints was likely a lepidosaur and may have been a sphenodont, an ancestor of the modern tuatara. The footprint consists of five digits, of which the fifth is shortened and the first highly shortened. Species *''R. beasleyi'' Nopsca, 1923 *''R. bornemanni'' Haubold, 1966 *''R. brunswickii'' Ryan and Willard, 1947 *''R. gangresci'' da Silva ''et al.'', 2012 *''R. hyperbates'' Baird, 1957 *''R. kuletae'' Baird, 1957 *''R. majus'' Demathieu, 1967 *''R. maximus'' Gand, 1974 *''R. minutipes'' Maidwell, 1914 *''R. pallinii'' Conti ''et al.', 1977 *''R. palmatus'' Lull, 1942 *''R. petri'' Demathieu, 1966 *''R. pusillus'' Haubold, 1966 *''R. rdzaneki'' Ptaszynski, 2000 *''R. rectipes'' Beasley, 1911 *''R. retroversipes'' da Silva ''et al.'', 2008 *''R. santanderensis'' Demathieu and Saiz de Omeñaca, 1977 *''R. schochardti'' von Lilienstern, 1939 *''R. sphaerodactylus'' Demathieu, 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therapsid
Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, as opposed to the sprawling posture of many reptiles and salamanders. Therapsids evolved from "pelycosaurs", specifically within the Sphenacodontia, more than 279.5 million years ago. They replaced the "pelycosaurs" as the dominant large land animals in the Middle Permian through to the Early Triassic. In the aftermath of the Permian–Triassic extinction event, therapsids declined in relative importance to the rapidly diversifying reptiles during the Middle Triassic. The therapsids include the cynodonts, the group that gave rise to mammals ( Mammaliaformes) in the Late Triassic, around 225 million years ago. Of the non-mammalian therapsids, only cynodonts survived beyond the end of the Triassic, with the only other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chirotherium
''Chirotherium'', also known as ''Cheirotherium'' (‘hand-beast’), is a Triassic trace fossil consisting of five-fingered (pentadactyle) footprints and whole tracks. These look, by coincidence, remarkably like the hands of apes and bears, with the outermost toe having evolved to extend out to the side like a thumb, although probably only functioning to provide a firmer grip in mud. ''Chirotherium'' tracks were first found in 1834 in Lower Triassic sandstone (Buntsandstein) in Thuringia, Germany, dating from about 243 million years ago ( mya). The creatures who made the footprints and tracks were probably pseudosuchian archosaurs related to the ancestors of the crocodiles. They likely belonged to either prestosuchidae or rauisuchidae groups, which were both large carnivores with semi-erect gaits. History ''Chirotherium'' tracks were first found in German Triassic sandstones in 1834, and later in England in 1838. They were found before dinosaurs were known and initial models o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachychirotherium
''Brachychirotherium'' is an ichnogenus, a form taxon based on footprints. It is a type of chirothere ('hand beast'), a term referring to the footprints of five-toed Triassic reptiles with a short fifth digit, leaving an appearance similar to a reverse human hand print. ''Brachychirotherium'' was first characterized from fossils found in Triassic beds in Germany, but has since been found in France, South Africa, Argentina, Peru, Bolivia, and North America. Description Front (manus) and rear (pes) footprints are distinguishable, though manus prints are not always preserved. The pes prints show five toes, which are proportionally shorter and stubbier than those of other chirotheres. Digit III is the longest, followed by digits II and IV, though they are all of a similar length. Digit I is notably shorter, and the impression of digit V is reduced to an oval pad at the sole. The manus prints likewise show up to five short digits, with the pad of digit V separate from the rest. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosaur
Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs, and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives, and Avemetatarsalia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs). Older definitions of the group Archosauria rely on shared morphological characteristics, such as an antorbital fenestra in the skull, serrated teeth, and an upright stance. Some extinct reptiles, such as proterosuchids and euparkeriids, possessed these features yet originated pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichnofossil
A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or mineralization. The study of such trace fossils is ichnology and is the work of ichnologists. Trace fossils may consist of impressions made on or in the substrate by an organism. For example, burrows, borings ( bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints and feeding marks and root cavities may all be trace fossils. The term in its broadest sense also includes the remains of other organic material produced by an organism; for example coprolites (fossilized droppings) or chemical markers (sedimentological structures produced by biological means; for example, the formation of stromatolites). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytosaur
Phytosaurs (Φυτόσαυροι in greek) are an extinct group of large, mostly semiaquatic Late Triassic archosauriform reptiles. Phytosaurs belong to the order Phytosauria. Phytosauria and Phytosauridae are often considered to be equivalent groupings containing the same species, but some studies have identified non-phytosaurid phytosaurians. Phytosaurs were long-snouted and heavily armoured, bearing a remarkable resemblance to modern crocodilians in size, appearance, and lifestyle, as an example of convergence or parallel evolution. The name "phytosaur" means "plant reptile", as the first fossils of phytosaurs were mistakenly thought to belong to plant eaters. The name is misleading because the sharp teeth in phytosaur jaws clearly show that they were predators. For many years, phytosaurs were considered to be the most basal group of Pseudosuchia (crocodile-line archosaurs), meaning that they were thought to be more closely related to the crocodilians than to birds (the othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
