Geochronology is the science of determining the age of rocks , fossils , and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes , whereas relative geochronology is provided by tools such as paleomagnetism and stable isotope ratios . By combining multiple geochronological (and biostratigraphic ) indicators the precision of the recovered age can be improved.
31-678: Geological formation in Daqing Mountains, China Naobaogou Formation Stratigraphic range : Lopingian ? PreꞒ Ꞓ O S D C P T J K Pg N Type Geological formation Sub-units Members I-III Underlies Laowopu Formation Overlies Shiyewan Formation Thickness More than 1000 m Lithology Primary Siltstone Other Conglomerate Location Country [REDACTED] China Extent Daqing Mountains The Naobaogou Formation
62-775: A proxy for the age at which a surface, such as an alluvial fan, was created. Burial dating uses the differential radioactive decay of 2 cosmogenic elements as a proxy for the age at which a sediment was screened by burial from further cosmic rays exposure. Luminescence dating techniques observe 'light' emitted from materials such as quartz, diamond, feldspar, and calcite. Many types of luminescence techniques are utilized in geology, including optically stimulated luminescence (OSL), cathodoluminescence (CL), and thermoluminescence (TL). Thermoluminescence and optically stimulated luminescence are used in archaeology to date 'fired' objects such as pottery or cooking stones and can be used to observe sand migration. Incremental dating techniques allow
93-487: A reference for newly obtained poles for the rocks with unknown age. For paleomagnetic dating, it is suggested to use the APWP in order to date a pole obtained from rocks or sediments of unknown age by linking the paleopole to the nearest point on the APWP. Two methods of paleomagnetic dating have been suggested: (1) the angular method and (2) the rotation method. The first method is used for paleomagnetic dating of rocks inside of
124-407: A subtriangular fontanelle on its premaxilla, a poorly ossified braincase, a well developed pterygoid flange, and a relatively narrow parasphenoid bearing a crest between the basicranial joint. CT-scanning also revealed the presence of canals within the mandible, snout, and bones in front of the orbit. The canals in the skull roof are interpreted as being related to a lateral line system. Canals in
155-514: Is a geological formation in the Daqing Mountains of China . It is likely of Lopingian (Late Permian) age. It consists of three rhythms of sediment, labelled members I-III primarily of purple siltstone , but each with a thick basal conglomerate bed. It is notable for its fossil content, producing one of the most diverse Late Permian vertebrate faunas outside Russia and South Africa. Vertebrate fauna [ edit ] Fauna of
186-687: Is also correct to say that fossils of the genus Tyrannosaurus have been found in the Upper Cretaceous Series. In the same way, it is entirely possible to go and visit an Upper Cretaceous Series deposit – such as the Hell Creek deposit where the Tyrannosaurus fossils were found – but it is naturally impossible to visit the Late Cretaceous Epoch as that is a period of time. Laosuchus Laosuchus
217-500: Is also often used as a dating tool in archaeology, since the dates of some eruptions are well-established. Geochronology, from largest to smallest: It is important not to confuse geochronologic and chronostratigraphic units. Geochronological units are periods of time, thus it is correct to say that Tyrannosaurus rex lived during the Late Cretaceous Epoch. Chronostratigraphic units are geological material, so it
248-700: Is an extinct genus of chroniosuchian known from the Permian - Triassic boundary of Asia. Two species have been named. L. naga was found in the Luang Prabang Basin of Northern Laos , part of the Indochina block . The site was first discovered by J. B. H. Counillon in 1896 as part of the Pavie's third Mission. Counillon was tasked with mapping mineral resources for the French colonial empire. L. naga
279-461: Is different in application from biostratigraphy, which is the science of assigning sedimentary rocks to a known geological period via describing, cataloging and comparing fossil floral and faunal assemblages. Biostratigraphy does not directly provide an absolute age determination of a rock, but merely places it within an interval of time at which that fossil assemblage is known to have coexisted. Both disciplines work together hand in hand, however, to
310-533: Is distinguished from L. naga by several traits, including reduced palatal dentition , with a few denticles present on the vomer and pterygoid bones, and an irregular posterior cheek margin. The two families within chroniosuchia, Chroniosuchidae and Bystrowianidae , are differentiated primarily based on postcranial elements, such as the shape of their vertebrae and the degree of overlap between their dorsal osteoderms . Thus, while L. naga has numerous characteristics supporting its inclusion to chroniosuchia,
341-591: Is represented by a single skull and articulated left hemimandible designated as specimen MDS-LPQ 2005-09, stored at the Musée des Dinosaures in Savannakhet . The skull, roughly 26 centimeters in length, is similar in shape to that of crocodiles. Its long snout bore marginal labyrinthodont teeth with an average height of 9 millimeters. Its nares are similar in shape to Madygenerpeton pustulatus . Like M. pustulatus, it also has oval-shaped orbits that are raised above
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#1732790213838372-532: The Ar/ Ar dating method can be extended into the time of early human life and into recorded history. Some of the commonly used techniques are: A series of related techniques for determining the age at which a geomorphic surface was created ( exposure dating ), or at which formerly surficial materials were buried (burial dating). Exposure dating uses the concentration of exotic nuclides (e.g. Be, Al, Cl) produced by cosmic rays interacting with Earth materials as
403-622: The Naobaogou Formation Genus Species Material Notes Images Caodeyao C. liuyufengi Partial skull, mandible, humerus A eutherocephalian , closely related to Purlovia . [REDACTED] Daqingshanodon D. limbus Skull Dicynodont Dicynodontia Indeterminate Partial skulls 5 additional morphotypes in addition to Daqingshanodon and Turfanodon , 2 of which are closely related to
434-668: The Permian of China". Die Naturwissenschaften . 98 (5): 435–41. Bibcode : 2011NW.....98..435R . doi : 10.1007/s00114-011-0793-0 . PMID 21484260 . S2CID 20274349 . ^ Liu, Jun (2023-05-09). "The tetrapod fauna of the upper Permian Naobaogou Formation of China: 9. A new species of Gansurhinus (Reptilia: Captorhinidae) and a revision of Chinese captorhinids" . Journal of Vertebrate Paleontology . 42 (5): e2203200. doi : 10.1080/02724634.2023.2203200 . ISSN 0272-4634 . S2CID 243245020 . ^ Shi, Y.-T.; Liu, J. (2023). "The tetrapod fauna of
465-409: The amount of radioactive decay of a radioactive isotope with a known half-life , geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, and depending on the rate of decay, are used for dating different geological periods. More slowly decaying isotopes are useful for longer periods of time, but less accurate in absolute years. With
496-436: The construction of year-by-year annual chronologies, which can be fixed ( i.e. linked to the present day and thus calendar or sidereal time ) or floating. A sequence of paleomagnetic poles (usually called virtual geomagnetic poles), which are already well defined in age, constitutes an apparent polar wander path (APWP). Such a path is constructed for a large continental block. APWPs for different continents can be used as
527-416: The exception of the radiocarbon method , most of these techniques are actually based on measuring an increase in the abundance of a radiogenic isotope, which is the decay-product of the radioactive parent isotope. Two or more radiometric methods can be used in concert to achieve more robust results. Most radiometric methods are suitable for geological time only, but some such as the radiocarbon method and
558-1124: The former taxon and 3 or 4 related to Jimusaria . Elginia E. wuyongae Partial skull Pareiasaur Euchambersia E. liuyudongi Skull and lower jaw Akidnognathid therocephalian [REDACTED] Gansurhinus G. naobaogouensis Relatively complete skeleton of an immature individual Captorhinid Jimusaria J. monanensis Skulls, cervicals, scapula Dicynodontoid dicynodont Jiufengia J. jiai Partial skull and postcranial skeleton Akidnognathid therocephalian [REDACTED] Laosuchus L. hun Partial skull and postcranial skeleton Chroniosuchian Shiguaignathus S. wangi Partial skull Akidnognathid therocephalian [REDACTED] Turfanodon T. jiufengensis Relatively complete skeleton and skulls Dicynodontoid dicynodont [REDACTED] References [ edit ] ^ Liu, J.; Bever, G.S. (2018). Angielczyk, K. (ed.). "The tetrapod fauna of
589-551: The lack of postcranial elements in addition to several cranial traits preclude their inclusion to either family. As a result, L. naga was classified as Chroniosuchia incertae sedis . In the 2021 description of L. hun postcranial remains indicated that Laosuchus belonged to the Chroniosuchidae. The depositional environment that L. naga occurred in consisted of braided rivers transitioning into alluvial plains, with an input of volcanic sediment. In addition to this,
620-459: The point where they share the same system of naming strata (rock layers) and the time spans utilized to classify sublayers within a stratum. The science of geochronology is the prime tool used in the discipline of chronostratigraphy , which attempts to derive absolute age dates for all fossil assemblages and determine the geologic history of the Earth and extraterrestrial bodies . By measuring
651-466: The presence of a lateral line system and poorly ossified braincase imply that L. naga spent much of its time in the water. According to the paleontologists who described L. naga , Its placement in nonmarine sediment provides a line of support for the scenario that the North China Block , South China Block , and Indochina block were connected like a peninsula and linked to Laurussia during
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#1732790213838682-494: The pterygoid, contacting the maxilla. CT-scanning revealed an autapomorphic internal crest on the dorsal palate that follows the internal margin of the choanae. The parasphenoid bears a thin ventro-medial ridge, a condition also seen in Discosauriscus austriacus Its tabular horn and posterior squamosal contact, closing the otic notch. There are a number of traits that L. naga share with other chroniosuchians. It bears
713-426: The same age and of such distinctive composition and appearance that, despite their presence in different geographic sites, there is certainty about their age-equivalence. Fossil faunal and floral assemblages , both marine and terrestrial, make for distinctive marker horizons. Tephrochronology is a method for geochemical correlation of unknown volcanic ash (tephra) to geochemically fingerprinted, dated tephra . Tephra
744-700: The same continental block. The second method is used for the folded areas where tectonic rotations are possible. Magnetostratigraphy determines age from the pattern of magnetic polarity zones in a series of bedded sedimentary and/or volcanic rocks by comparison to the magnetic polarity timescale. The polarity timescale has been previously determined by dating of seafloor magnetic anomalies, radiometrically dating volcanic rocks within magnetostratigraphic sections, and astronomically dating magnetostratigraphic sections. Global trends in isotope compositions, particularly carbon-13 and strontium isotopes, can be used to correlate strata. Marker horizons are stratigraphic units of
775-481: The skull roof, but the orbits are proportionally smaller. Its choanae are relatively long compared to other chroniosuchians. L. naga has a number of traits that make it unique among chroniosuchia. It lacks palatal tusks, bearing only small denticles on the palate. Its pineal foramen is significantly reduced with a 1mm diameter( M. pustulatus, C. dongusensis , and B. schumanni have diameters of 2mm, 2.5mm, and 3.5mm respectively ). A transverse flange extends from
806-427: The tip of the snout and mandible are more complex and could be neurovascular canals, which modern animals use for thermoreception, electroreception , or mechanoreception . The paleontologists who described L. naga suggest that the lateral line system was used to detect prey beneath the water surface while the neurovascular system could let it detect movement at the water surface similar to modern crocodiles. L. hun
837-544: The upper Permian Naobaogou Formation of China: 10. Jimusaria monanensis sp. nov. (Dicynodontia) shows a unique epipterygoid" . PeerJ . 11 : e15783. doi : 10.7717/peerj.15783 . ISSN 2167-8359 . PMC 10399559 . PMID 37547715 . ^ Liu J, Abdala F (2019-02-22). "Jiufengia jiai gen. et sp. nov., a large akidnognathid therocephalian" . PeerJ . 7 : e6463. doi : 10.7717/peerj.6463 . PMC 6388668 . PMID 30809450 . ^ Liu, J.; Chen, J. (2021). "The tetrapod fauna of
868-850: The upper Permian Naobaogou Formation of China: 7. Laosuchus hun sp. nov. (Chroniosuchia) and interrelationships of chroniosuchians". Journal of Systematic Palaeontology . 18 (24): 2043–2058. doi : 10.1080/14772019.2021.1873435 . S2CID 232116225 . ^ Liu J, Abdala F (2017-12-06). "Shiguaignathus wangi gen. et sp. nov., the first akidnognathid therocephalian from China" . PeerJ . 5 : e4150. doi : 10.7717/peerj.4150 . PMC 5723136 . PMID 29230374 . Retrieved from " https://en.wikipedia.org/w/index.php?title=Naobaogou_Formation&oldid=1173277556 " Categories : Permian System of Asia Permian China Lopingian geology Hidden categories: Articles with short description Short description matches Wikidata Geochronology Geochronology
899-888: The upper Permian Naobaogou Formation of China: a new species of Elginia (Parareptilia, Pareiasauria)". Papers in Palaeontology . 4 (2): 197–209. doi : 10.1002/spp2.1105 . S2CID 135273110 . ^ Liu, Jun; Abdala, Fernando (2020-05-28). "The tetrapod fauna of the upper Permian Naobaogou Formation of China: 5. Caodeyao liuyufengi gen. et sp. nov., a new peculiar therocephalian" . PeerJ . 8 : e9160. doi : 10.7717/peerj.9160 . ISSN 2167-8359 . PMC 7261480 . PMID 32523808 . ^ Zhuh Y (1989). "The discovery of dicynodonts in Daqingshan Mountain, Nei Mongol (Inner Mongolia)" (PDF) . Vertebrata PalAsiatica . 27 (1): 9–27. ^ Liu, J. (2019). "The tetrapod fauna of
930-575: The upper Permian Naobaogou Formation of China— 4. the diversity of dicynodonts" . Vertebrata PalAsiatica : 173–180. doi : 10.19615/j.cnki.1000-3118.190522 . ^ Liu, J. (2021). "The tetrapod fauna of the upper Permian Naobaogou Formation of China: 6. Turfanodon jiufengensis sp. nov. (Dicynodontia)" . PeerJ . 9 (e10854): e10854. doi : 10.7717/peerj.10854 . PMC 7896508 . PMID 33643709 . ^ Reisz RR, Liu J, Li JL, Müller J (May 2011). "A new captorhinid reptile, Gansurhinus qingtoushanensis, gen. et sp. nov., from
961-515: Was discovered during a 2005 expedition to the area, along with remains of dicynodonts . It was later described by Arbez, Sidor, and Steyer in 2018. Its name comes from the Nāga , a snake-like deity that appears in multiple east Asian religions. In 2021 a new species L. hun was described from the Naobaogou Formation of the Daqing Mountains of Inner Mongolia , China. Laosuchus naga