Misplaced Pages

#660339

58-505: Triassic geologic unit in southern China Zhuganpo Formation Stratigraphic range : Upper Ladinian - Lower Carnian Type Geological formation Underlies Xiaowa Formation Overlies Yangliujing Formation Lithology Primary limestone , marl Location Region Guizhou Province , Yunnan Province Country China Extent Yunnan–Guizhou Plateau The Zhuganpo Formation

116-2140: A Ladinian to Carnian age for the sediments of the formation. Paleobiota [ edit ] Invertebrates [ edit ] Ammonites : Clionitites sp., Detoniceras sp., Haoceras xingyiense , Parasturia sp., Protrachyceras sp., Ptychites sp., Sinomeginoceras ( S. wangi, S. xingyiense ), Trachyceras sp., Xenoprotrachyceras cf. primum , Yangites densicostatus , Bivalves : Daonella sp. Conodonts : Gladigondolella malayensis , Metapolygnathus / Paragondolella / Quadralella ( Q. aff . acuminatus, P. foliata, P. inclinata, Q. intermedius, Q. langdaiensis, P. maantangensis, P. navicula, M. nodosus, M. parafoliata, Q. aff . praelindae, P. polygnathiformis, Q. shijiangjunensis, Q. tadpole, Q. uniformis, Q. wanlanensis, Q. aff . wayaoensis, Q. yongueensis, Q. aff. zonneveldi ) Crinoids : Traumatocrinus hsui Crustaceans ("shrimps"): Schimperella acanthocercus ( Lophogastrida ) Fish [ edit ] Acrolepidae indet. Archaesemionotus sp . aff. Arctacanthus sp. ( Chimaeriformes ?) Asialepidotus shingyiensis ( Ionoscopiformes ) Birgeria liui Caturidae indet. Eosemionotus sp . Favusodus orientalis ( Euselachii ) Fuyuanichthys wangi ( Ginglymodi ) Fuyuanperleidus dengi Guizhouamia bellula Guizhoubrachysomus minor Guizhoucoelacanthus guanlingensis Guizhouniscus microlepidus Habroichthys sp . Keichouodus nimaiguensis (Euselachii) Luganoia fortuna ( Luganoiidae ) Malingichthys ( M. nimaiguensis, M. wanfendlinensis ; Pholidophoridae ) Marcopoloichthys sp . Peltopleurus (P. orientalis, P. tyrannos) Peripeltopleurus sp . ( Wushaichthyidae ) Pholidophoridae indet. Potanichthys xingyiensis ( Thoracopteridae ) Rosaodus xingyiensis ( Elasmobranchii ) Saurichthys sp . Sinoeugnathus kueichowensis Wushaichthys exquisitus (Wushaichthyidae) Xingyia gracilis Reptiles [ edit ] Reptiles of

174-1898: A basal phytosaur Dingxiaosaurus D. luyinensis A pistosauroid of uncertain validity. Previously believed to have been from the Yangliujing Formation . Fuyuansaurus F. acutirostris A " protorosaur " archosauromorph , possibly a tanystropheid Glyphoderma G. kangi A placochelyid placodont Guizhouichthyosaurus G. sp. A large predatory merriamosaurian ichthyosaur Keichousaurus K. hui A keichousaurid pachypleurosaur Lariosaurus L. xingyiensis A small nothosaur Litorosuchus L. somnii A semiaquatic archosauriform related to Vancleavea campi Macrocnemus M. fuyuanensis A small basal tanystropheid Nothosaurus N. youngi A large nothosaur Qianichthyosaurus Q. xingyiensis A small toretocnemid ichthyosaur Qianxisaurus Q. chajiangensis A basal eosauropterygian , possibly related to pachypleurosaurs or nothosaurs Tanystropheus T. cf. hydroides A large tanystropheid, previously classified as T. cf. longobardicus T. sp. A small tanystropheid, previously classified as T. cf. longobardicus Wangosaurus W. brevirostris A pistosauroid Xinpusaurus X. xingyiensis A thalattosauroid thalattosaur Yunguisaurus Y. liae A pistosauroid References [ edit ] ^ Benton, Michael J.; Zhang, Qiyue; Hu, Shixue; Chen, Zhong-Qiang; Wen, Wen; Liu, Jun; Huang, Jinyuan; Zhou, Changyong; Xie, Tao; Tong, Jinnan; Choo, Brian (2013-10-01). "Exceptional vertebrate biotas from

232-775: 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

290-487: 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

348-922: A sustainable level, though Callorhinchus milii (the Australian ghostshark ) experienced severe overfishing in the 20th century before protections were enacted. Neoharriotta pinnata ( sicklefin chimaera ) is targeted along the coast of India for its liver oil, and a recent decline of catch rates may indicate a population crash. Even species without commercial exploitation can fall victim to bycatch: Callorhinchus callorynchus ( American elephantfish ), Neoharriotta carri ( dwarf sicklefin chimaera ), Chimaera monstrosa ( rabbit fish ), Chimaera ogilbyi ( Ogilby's ghostshark ), Hydrolagus colliei ( spotted ratfish ), and Hydrolagus melanophasma ( eastern Pacific black ghostshark ) all have bycatch rates exceeding 10% in certain parts of their range, and some are experiencing steep declines. Chimaeras have mostly avoided harvesting for

406-424: A unique hypermineralized tissue called pleromin . Pleromin is an extremely hard enamel -like tissue, arranged into sheets or beaded rods, but it is deposited by mesenchyme -derived cells similar to those that form bone . In addition, pleuromin's hardness is due to the mineral whitlockite , which crystalizes within the teeth as the animal matures. Other vertebrates with hypermineralized teeth rely on enamel, which

464-701: Is Protochimaera from the Early Carboniferous (338–332 million years ago) of Russia, which is more closely related to modern chimeras (Chimaeroidei) than any other known extinct groups of Chimaeriformes. The earliest known remains attributable to modern chimaeras are known from the Early Jurassic ( Pliensbachian ) of Europe, but egg cases from the Late Triassic of Yakutia, Russia and New Zealand that resemble those of rhinochimaerids and callorhinchids respectively indicates that they had

522-621: Is holostylic , meaning that the palatoquadrate (upper jaw cartilage) is completely fused to the neurocranium (cranial cartilage). This contrasts with modern sharks, where the palatoquadrate is movable and detachable, a trait known as hyostyly . The back of the head is supported by a complex of fused vertebrae called the synarcual, which also connects to the dorsal fin spine. Instead of sharks' many sharp, consistently-replaced teeth, chimaeras have just six large, permanent tooth-plates, which grow continuously throughout their entire life. These tooth-plates are arranged in three pairs, with one pair at

580-726: Is a Triassic geologic unit found in southern China . It has historically been known as the Zhuganpo Member of the Falang Formation. A diverse fossil assemblage known as the Xingyi biota or Xingyi Fauna can be found in the upper part of the Zhuganpo Formation. Fossils of the Xingyi biota include articulated skeletons of marine reptiles, abundant fish, and a plentiful assortment of invertebrates indicating

638-669: Is a monogenean parasite of the gills of Chimaera monstrosa ; the species can attain 50 mm (2.0 in) in length. Despite their secluded habits, some chimaera species may be threatened by overfishing through bycatch or commercial exploitation. No species are listed as Endangered according to the IUCN , but four are listed as Vulnerable , four more as Near Threatened , and many more as Data Deficient (too rare to evaluate). Many species have restricted ranges and practically none have had their movement patterns studied. In addition, bycatch reports are usually insufficiently precise to

SECTION 10

#1732786650661

696-721: 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. Chimaeriformes Chimaeras are cartilaginous fish in

754-500: 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

812-406: Is derived from ameloblasts and encases round crystals of the mineral apatite . Chimaeras also differ from sharks in that they have separate anal and urogenital openings. Chimaeras live in temperate ocean floors, with some species inhabiting depths exceeding 2,000 m (6,600 ft), with relatively few modern species regularly inhabiting shallow water. Exceptions include the members of

870-461: 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

928-532: 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

986-469: The fin trade , which threatens many true sharks. Another threat is habitat destruction of coastal nurseries (by urban development) or deepwater reefs (by deep sea mining and trawling ). Near-shore species such as Callorhinchus milii are vulnerable to the effects of climate change : stronger storms and warmer seawater are predicted to increase egg mortality by disrupting the stable environments necessary to complete incubation. In some classifications,

1044-617: The genus Callorhinchus , the rabbit fish and the spotted ratfish , which locally or periodically can be found at shallower depths. Consequently, these are also among the few species kept in public aquaria . They live in all the oceans except for the Arctic and Antarctic oceans. The usual diet of chimaeras consist of crustaceans , and more specifically, they include ophiurans and molluscs. Modern species are demersal durophages , but they used to be more diverse. The Carboniferous period had forms that lived as specialised suction feeders in

1102-636: The order Chimaeriformes ( / k ɪ ˈ m ɛ r ɪ f ɔːr m iː z / ), known informally as ghost sharks , rat fish , spookfish , or rabbit fish ; the last three names are not to be confused with rattails , Opisthoproctidae , or Siganidae , respectively. At one time a "diverse and abundant" group (based on the fossil record ), their closest living relatives are sharks and rays , though their last common ancestor with them lived nearly 400 million years ago. Living species are largely confined to deep water. Chimaeras are soft-bodied, shark-like fish with bulky heads and long, tapered tails; measured from

1160-474: The pectoral fins . The pectoral fins are large enough to generate lift at a relaxed forward momentum, giving the chimaera the appearance of "flying" through the water. Further back on the body are also a pair of smaller pelvic fins , and some genera bear an anal fin in front of the tail. In chimaerids and rhinochimaerids , the tail is leptocercal , meaning that it is thin and whip-like, edged from above and below by fins of similar size. In callorhinchids ,

1218-750: The Ladinian (Middle Triassic) Zhuganpo Member, Falang Formation, Guizhou, China and the restudy of Dingxiaosaurus" . Palaeoworld . 29 (1): 137–150. doi : 10.1016/j.palwor.2019.05.006 . S2CID   181711576 . ^ Fraser, Nicholas C.; Rieppel, Olivier; Chun, Li (2013). "A long-snouted protorosaur from the Middle Triassic of southern China" . Journal of Vertebrate Paleontology . 33 (5): 1120–1126. Bibcode : 2013JVPal..33.1120F . doi : 10.1080/02724634.2013.764310 . ISSN   0272-4634 . S2CID   83521468 . ^ Ezcurra, Martín D.; Butler, Richard J. (2018-06-13). "The rise of

SECTION 20

#1732786650661

1276-490: The Ladinian (Middle Triassic) of Xingyi, Guizhou, southwestern China" . Journal of Vertebrate Paleontology . 36 (6): e1218340. Bibcode : 2016JVPal..36E8340L . doi : 10.1080/02724634.2016.1218340 . ISSN   0272-4634 . S2CID   132418823 . ^ Sato, Tamaki; Zhao, Li-Jun; Wu, Xiao-Chun; Li, Chun (2014). Ruta, Marcello (ed.). "A new specimen of the Triassic pistosauroid Yunguisaurus, with implications for

1334-547: The Ladinian–Carnian interval of South China" . Papers in Palaeontology . 8 (1). Bibcode : 2022PPal....8E1404L . doi : 10.1002/spp2.1404 . ISSN   2056-2799 . S2CID   241980979 . ^ Xu, Guang-Hui; Ma, Xin-Ying (2018-01-27). "Redescription and phylogenetic reassessment of Asialepidotus shingyiensis (Holostei: Halecomorphi) from the Middle Triassic (Ladinian) of China" . Zoological Journal of

1392-741: The Linnean Society . 184 (1): 95–114. doi : 10.1093/zoolinnean/zlx105 . ISSN   0024-4082 . ^ Ni, Peigang; Tintori, Andrea; Sun, Zuoyu; Lombardo, Cristina; Jiang, Dayong (2019-12-01). "Postcranial skeleton of Birgeria liui (Osteichthyes, Actinopterygii) from the Longobardian (Ladinian, Middle Triassic) of Xingyi, Guizhou, South China" . Swiss Journal of Geosciences . 112 (2): 307–324. doi : 10.1007/s00015-018-0329-0 . ISSN   1661-8734 . S2CID   135305199 . ^ Xu, Guang-Hui; Ma, Xin-Ying; Ren, Yi (2018-12-20). "Fuyuanichthys wangi gen. et sp. nov. from

1450-994: The Middle Triassic (Ladinian) of China highlights the early diversification of ginglymodian fishes" . PeerJ . 6 : e6054. doi : 10.7717/peerj.6054 . ISSN   2167-8359 . PMC   6304272 . PMID   30595977 . ^ Guang-Hui, Xu (2020). "A new species of Luganoia (Luganoiidae, Neopterygii) from the Middle Triassic Xingyi Biota, Guizhou, China" (PDF) . Vertebrata PalAsiatica . 58 (4): 267–282. doi : 10.19615/j.cnki.1000-3118.200624 . ^ TINTORI, ANDREA; SUN, ZUOYU; NI, PEIGANG; LOMBARDO, CRISTINA; JIANG, DAYONG; MOTANI, RYOSUKE (2015-11-19). "OLDEST STEM TELEOSTEI FROM THE LATE LADINIAN (MIDDLE TRIASSIC) OF SOUTHERN CHINA" . Rivista italiana di Paleontologia e Stratigrafia . 121 : 3. doi : 10.13130/2039-4942/6519 . ^ Xu Guang-Hi, Ma Xin-Ying, Zhao Li-Jun (2018). "A large peltopleurid fish (Actinopterygii: Peltopleuriformes) from

1508-1494: The Middle Triassic of China shows the earliest over-water gliding strategy of the vertebrates" . Proceedings of the Royal Society B: Biological Sciences . 280 (1750): 20122261. doi : 10.1098/rspb.2012.2261 . PMC   3574442 . PMID   23118437 . ^ Xu, Guang-Hui; Zhao, Li-Jun; Shen, Chen-Chen (2015). "A Middle Triassic thoracopterid from China highlights the evolutionary origin of overwater gliding in early ray-finned fishes" . Biology Letters . 11 (1): 20140960. doi : 10.1098/rsbl.2014.0960 . ISSN   1744-9561 . PMC   4321159 . PMID   25568155 . ^ Cheng, L.; Chen, X.; Wang, C. (2007). "A new species of Late Triassic Anshunsaurus (Reptilia: Thalattosauria) from Guizhou Province" . Acta Geologica Sinica (in Chinese). 81 (10): 1345–1351. ^ Long, Cheng; Xiaohong, Chen; Baomin, Zhang; Yongjian, Cai (2011). "New Study of Anshunsaurus huangnihensis Cheng, 2007 (Reptilia: Thalattosauria): Revealing its Transitional Position in Askeptosauridae" . Acta Geologica Sinica - English Edition . 85 (6): 1231–1237. Bibcode : 2011AcGlS..85.1231C . doi : 10.1111/j.1755-6724.2011.00584.x . S2CID   129819570 . ^ Rieppel, O.; Liu, J.; Li, C. (2006). "A new species of

1566-731: The Middle Triassic of Guizhou, China" . Journal of Vertebrate Paleontology . 34 (2): 465–470. Bibcode : 2014JVPal..34..465J . doi : 10.1080/02724634.2013.808204 . ISSN   0272-4634 . S2CID   84886121 . ^ Yang, P.F., Ji, C., Jiang, D.Y., Motani, R., Tintori, A., Sun, Y.L., Sun, Z.Y. (2013). "A new species of Qianichthyosaurus (Reptilia: Ichthyosauria) from Xingyi Fauna (Ladinian, Middle Triassic) of Guizhou". Acta Scientiarum Naturalium Universitatis Pekinensis (in Chinese). 49 : 1002–1008. {{ cite journal }} : CS1 maint: multiple names: authors list ( link ) ^ Cheng, Y. N.; Wu, X. C.; Sato, T.; Shan, H. Y. (2012). "A new eosauropterygian (Diapsida, Sauropterygia) from

1624-744: The Middle Triassic of Yunnan and Guizhou, China" . Vertebrata PalAsiatica . 56 (2): 106–120. doi : 10.19615/j.cnki.1000-3118.171225 . {{ cite journal }} : CS1 maint: multiple names: authors list ( link ) ^ Shen, Chenchen; Arratia, Gloria (2021-10-02). "Re-description of the sexually dimorphic peltopleuriform fish Wushaichthys exquisitus (Middle Triassic, China): taxonomic implications and phylogenetic relationships" . Journal of Systematic Palaeontology . 19 (19): 1317–1342. Bibcode : 2021JSPal..19.1317S . doi : 10.1080/14772019.2022.2029595 . ISSN   1477-2019 . S2CID   247731689 . ^ Xu, G. -H.; Zhao, L. -J.; Gao, K. -Q.; Wu, F. -X. (2012). "A new stem-neopterygian fish from

1682-881: The Triassic of China" . Canadian Journal of Earth Sciences . 40 (4): 621–634. Bibcode : 2003CaJES..40..621R . doi : 10.1139/e02-067 . ^ Wen-Bin Lin; Da-Yong Jiang; Olivier Rieppel; Ryosuke Motani; Cheng Ji; Andrea Tintori; Zuo-Yu Sun; Min Zhou (2017). "A new specimen of Lariosaurus xingyiensis (Reptilia, Sauropterygia) from the Ladinian (Middle Triassic) Zhuganpo Member, Falang Formation, Guizhou, China" . Journal of Vertebrate Paleontology . 37 (2). e1278703. Bibcode : 2017JVPal..37E8703L . doi : 10.1080/02724634.2017.1278703 . S2CID   90181915 . ^ Li, Chun; Wu, Xiao-chun; Zhao, Li-jun; Nesbitt, Sterling J.; Stocker, Michelle R.; Wang, Li-Ting (2016-11-09). "A new armored archosauriform (Diapsida: Archosauromorpha) from

1740-794: The Triassic of China". Journal of Vertebrate Paleontology . 32 (6): 1335. Bibcode : 2012JVPal..32.1335C . doi : 10.1080/02724634.2012.695983 . S2CID   85253142 . ^ Spiekman, Stephan N. F.; Neenan, James M.; Fraser, Nicholas C.; Fernandez, Vincent; Rieppel, Olivier; Nosotti, Stefania; Scheyer, Torsten M. (2020-11-20). "The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography" . PeerJ . 8 : e10299. doi : 10.7717/peerj.10299 . ISSN   2167-8359 . PMC   7682440 . PMID   33240633 . ^ Rieppel, Olivier; Jiang, Da-Yong; Fraser, Nicholas C.; Hao, Wei-Cheng; Motani, Ryosuke; Sun, Yuan-Lin; Sun, Zuo-Yu (2010). " Tanystropheus cf. T. Longobardicus from

1798-851: The Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction" . Earth-Science Reviews . 125 : 199–243. Bibcode : 2013ESRv..125..199B . doi : 10.1016/j.earscirev.2013.05.014 . ISSN   0012-8252 . ^ Lu, Hao; Jiang, Da-Yong; Motani, Ryosuke; Ni, Pei-Gang; Sun, Zuo-Yu; Tintori, Andrea; Xiao, Shi-Zhen; Zhou, Min; Ji, Cheng; Fu, Wan-Lu (2018). "Middle Triassic Xingyi Fauna: Showing turnover of marine reptiles from coastal to oceanic environments" . Palaeoworld . 27 (1): 107–116. doi : 10.1016/j.palwor.2017.05.005 . ^ Xiaodong Xu, Marco Balini, Da-Yong Jiang, Andrea Tintori, Zuo-Yu Sun, Yuan-Lin Sun (2015). "Ammonoids from

Zhuganpo Formation - Misplaced Pages Continue

1856-692: The Zhuganpo Formation Genus Species Notes Images Anshunsaurus A. huangnihensis An askeptosauroid thalattosaur [REDACTED] Diandongosuchus fuyuanensis [REDACTED] Keichousaurus hui [REDACTED] Guizhouichthyosaurus A. wushaensis An askeptosauroid thalattosaur Brevicaudosaurus B. jiyangshanensis A small nothosaur with an unusually short torso and tail Diandongosuchus D. fuyuanensis A semiaquatic archosauriform , interpreted as

1914-1966: The Zhuganpo Member of the Falang Formation at Nimaigu and their relevance for dating the Xingyi Fossil-Lagerstatte (Late Ladinian, Guizhou, China)" . Rivista Italiana di Paleontologia e Stratigrafia . 121 (2): 135–161. {{ cite journal }} : CS1 maint: multiple names: authors list ( link ) ^ Sun, Zuoyu; Jiang, Dayong; Ji, Cheng; Hao, Weicheng (2016). "Integrated biochronology for Triassic marine vertebrate faunas of Guizhou Province, South China" . Journal of Asian Earth Sciences . 118 : 101–110. Bibcode : 2016JAESc.118..101S . doi : 10.1016/j.jseaes.2016.01.004 . ^ Zhang, Z. T.; Sun, Y. D.; Lai, X. L.; Joachimski, M. M.; Wignall, P. B. (2017-11-15). "Early Carnian conodont fauna at Yongyue, Zhenfeng area and its implication for Ladinian-Carnian subdivision in Guizhou, South China" . Palaeogeography, Palaeoclimatology, Palaeoecology . The Palaeozoic-Mesozoic Transition in South China: Oceanic Environments and Life from Late Permian to Late Triassic. 486 : 142–157. Bibcode : 2017PPP...486..142Z . doi : 10.1016/j.palaeo.2017.02.011 . ISSN   0031-0182 . ^ Taylor, Rod S.; Schram, Frederick R.; Yan-Bin, Shen (2001). "A new upper Middle Triassic shrimp (Crustacea: Lophogastrida) from Guizhou, China, with discussion regarding other fossil "mysidaceans" " . Journal of Paleontology . 75 (2): 310–318. doi : 10.1666/0022-3360(2001)075<0310:ANUMTS>2.0.CO;2 . ISSN   0022-3360 . S2CID   131509616 . ^ Li, Jiachun; Sun, Zuoyu; Cuny, Gilles; Ji, Cheng; Jiang, Dayong; Zhou, Min (2022). Cavin, Lionel (ed.). "An unusual shark assemblage from

1972-409: 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

2030-413: The chimaeras are included (as subclass Holocephali ) in the class Chondrichthyes of cartilaginous fishes; in other systems, this distinction may be raised to the level of class. Chimaeras also have some characteristics of bony fishes . A renewed effort to explore deep water and to undertake taxonomic analysis of specimens in museum collections led to a boom during the first decade of the 21st century in

2088-436: 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

2146-408: The early Late Triassic of Guizhou Province, southwestern China". Journal of Vertebrate Paleontology . 30 (4): 1082–1089. Bibcode : 2010JVPal..30.1082R . doi : 10.1080/02724634.2010.483548 . JSTOR   40864387 . S2CID   86315078 . ^ Ma, Le-Tian; Jiang, Da-Yong; Rieppel, Olivier; Motani, Ryosuke; Tintori, Andrea (2015-01-02). "A new pistosauroid (Reptilia, Sauropterygia) from

2204-1172: The early evolution of stem archosaurs" . PeerJ . 9 : e11143. doi : 10.7717/peerj.11143 . ISSN   2167-8359 . PMC   8101476 . PMID   33986981 . ^ Zhao, L.-J.; Li, C.; Liu, J.; He, T. (2008). "A new armored placodont from the Middle Triassic of Yunnan Province, Southwestern China" (PDF) . Vertebrata PalAsiatica . 46 (3): 171–177. Archived from the original (PDF) on 3 March 2016. ^ Jiang, D. Y.; Motani, R.; Tintori, A.; Rieppel, O.; Ji, C.; Zhou, M.; Wang, X.; Lu, H.; Li, Z. G. (2020). "Evidence supporting predation of 4-m marine reptile by Triassic megapredator" . iScience . 23 (9): 101347. Bibcode : 2020iSci...23j1347J . doi : 10.1016/j.isci.2020.101347 . PMC   7520894 . PMID   32822565 . ^ Cheng, Yen-nien; Wu, Xiao-chun; Ji, Qiang (2004). "Triassic marine reptiles gave birth to live young" . Nature . 432 (7015): 383–386. Bibcode : 2004Natur.432..383C . doi : 10.1038/nature03050 . ISSN   1476-4687 . PMID   15549103 . S2CID   4391810 . ^ Holmes, Robert; Cheng, Yen-Nien; Wu, Xiao-Chun (2008-03-12). "New information on

2262-472: The evolution of these species has been problematic given the paucity of good fossils. DNA sequencing has become the preferred approach to understanding speciation. The group containing chimaeras and their close relatives ( Holocephali ) is thought to have diverged from Elasmobranchii (the group containing modern sharks and rays) during the Devonian , over 380 million years ago. The oldest known chimaeriform

2320-416: 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

2378-464: The females' pectoral fins during mating. The prepelvic tentacula are serrated hooked plates normally hidden in pouches in front of the pelvic fins, and they anchor the male to the female. Lastly, the pelvic claspers (sexual organs shared by sharks) are fused together by a cartilaginous sheathe before splitting into a pair of flattened lobes at their tip. As other fish, chimaeras have a number of parasites . Chimaericola leptogaster ( Chimaericolidae )

Zhuganpo Formation - Misplaced Pages Continue

2436-423: The late Ladinian Xingyi marine reptile level, southwestern China" . Journal of Vertebrate Paleontology . 35 (1): e881832. Bibcode : 2015JVPal..35E1832M . doi : 10.1080/02724634.2014.881832 . ISSN   0272-4634 . S2CID   130696958 . ^ Li, Z.-G.; Jiang, D.-Y.; Rieppel, O.; Motani, R.; Tintori, A.; Sun, Z.-Y.; Ji, C. (2016-11-01). "A new species of Xinpusaurus (Reptilia, Thalattosauria) from

2494-510: The marine Middle Triassic of China, with implications for the diverse life styles of archosauriforms prior to the diversification of Archosauria" . The Science of Nature . 103 (11): 95. Bibcode : 2016SciNa.103...95L . doi : 10.1007/s00114-016-1418-4 . ISSN   1432-1904 . PMID   27830290 . S2CID   253634068 . ^ Jiang, Da-Yong; Rieppel, Olivier; Fraser, Nicholas C.; Motani, Ryosuke; Hao, Wei-Cheng; Tintori, Andrea; Sun, Yuan-Lin; Sun, Zuo-Yu (2011). "New information on

2552-799: The marine Triassic of China" . Journal of Vertebrate Paleontology . 32 (5): 1064. Bibcode : 2012JVPal..32.1064L . doi : 10.1080/02724634.2012.694383 . S2CID   86797826 . ^ Michelle R. Stocker; Li-Jun Zhao; Sterling J. Nesbitt; Xiao-Chun Wu; Chun Li (2017). "A Short-Snouted, Middle Triassic Phytosaur and its Implications for the Morphological Evolution and Biogeography of Phytosauria" . Scientific Reports . 7 : Article number 46028. Bibcode : 2017NatSR...746028S . doi : 10.1038/srep46028 . PMC   5385495 . PMID   28393843 . ^ Wang, Xue; Lu, Hao; Jiang, Da-Yong; Zhou, Min; Sun, Zuo-Yu (2020). "A new specimen of Yunguisaurus (Reptilia; Sauropterygia) from

2610-478: The number of new species identified. A preliminary study found 8% of species to be threatened. There are over 50 extant species in six genera and three families, with other genera known from fossils. The extant species fall into three families—the Callorhinchidae, Rhinochimaeridae and Chimaeridae with the callorhinchids being the most basal clade . Suborder Chimaeroidei Patterson 1965 Tracing

2668-867: The origin of Plesiosauria (Reptilia, Sauropterygia)" . Palaeontology . 57 (1): 55–76. Bibcode : 2014Palgy..57...55S . doi : 10.1111/pala.12048 . S2CID   129457774 . Retrieved from " https://en.wikipedia.org/w/index.php?title=Zhuganpo_Formation&oldid=1255359736 " Categories : Geologic formations of China Triassic System of Asia Triassic China Carnian Stage Ladinian Stage Paleontology in Guizhou Paleontology in Yunnan Hidden categories: CS1 maint: multiple names: authors list CS1 Chinese-language sources (zh) Articles with short description Short description with empty Wikidata description Geochronology Geochronology

2726-459: 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

2784-538: The protorosaurian reptile Macrocnemus fuyuanensis Li et al., 2007, from the Middle/Upper Triassic of Yunnan, China" . Journal of Vertebrate Paleontology . 31 (6): 1230–1237. Bibcode : 2011JVPal..31.1230J . doi : 10.1080/02724634.2011.610853 . ISSN   0272-4634 . S2CID   131615836 . ^ Ji, Cheng; Jiang, Da-Yong; Rieppel, Olivier; Motani, Ryosuke; Tintori, Andrea; Sun, Zuo-Yu (2014-03-01). "A new specimen of Nothosaurus youngi from

2842-461: The ruling reptiles and ecosystem recovery from the Permo-Triassic mass extinction" . Proc. R. Soc. B . 285 (1880): 20180361. doi : 10.1098/rspb.2018.0361 . ISSN   0962-8452 . PMC   6015845 . PMID   29899066 . ^ Spiekman, Stephan N. F.; Fraser, Nicholas C.; Scheyer, Torsten M. (2021-05-03). "A new phylogenetic hypothesis of Tanystropheidae (Diapsida, Archosauromorpha) and other "protorosaurs", and its implications for

2900-426: 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

2958-700: 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

SECTION 50

#1732786650661

3016-403: The skull of Keichousaurus hui (Reptilia: Sauropterygia) with comments on sauropterygian interrelationships" . Journal of Vertebrate Paleontology . 28 (1): 76–84. doi : 10.1671/0272-4634(2008)28[76:NIOTSO]2.0.CO;2 . ISSN   0272-4634 . S2CID   85868385 . ^ Rieppel, Olivier; Jinling, Li; Jun, Liu (2003). "Lariosaurus xingyiensis (Reptilia: Sauropterygia) from

3074-471: The species or even genus level, so it is difficult to keep track of bycatch on a species-by-species basis. This lack of data renders chimaera species especially susceptible to overlooked population declines. Several near-shore species are purposefully caught for their meat, especially callorhinchids, Hydrolagus bemisi ( pale ghost shark ), and Hydrolagus novaezealandi ae ( dark ghost shark ). Modern quotas have helped to moderate collection of these species to

3132-465: The tail is instead heterocercal , with a larger upper lobe inclined upwards, similar to many sharks. There are two dorsal fins: a large triangular first dorsal fin and a low rectangular or depressed second dorsal fin. For defense, some chimaeras have a venomous spine on the front edge of the dorsal fin . In many species, the bulbous snout is modified into an elongated sensory organ, capable of electroreception to find prey. The cartilaginous skull

3190-410: The tail, they can grow up to 150 cm (4.9 ft) in length. Like other members of the class Chondrichthyes , chimaera skeletons are entirely cartilaginous, or composed of cartilage . Males use forehead denticles to grasp a female by a fin during copulation. The gill arches are condensed into a pouch-like bundle covered by a sheet of skin (an operculum ), with a single gill -opening in front of

3248-905: The thalattosaur genus Anshunsaurus (Reptilia: Thalattosauria) from the Middle Triassic of Guizhou Province, southwestern China" . Vertebrata PalAsiatica . 44 : 285–296. ^ Liu, J. (2007). "A juvenile specimen of Anshunsaurus (Reptilia: Thalattosauria)" . American Museum Novitates (3582): 1–9. doi : 10.1206/0003-0082(2007)3582[1:ajsoar]2.0.co;2 . ISSN   0003-0082 . S2CID   85916769 . ^ Shang, Qing-Hua; Wu, Xiao-Chun; Li, Chun (2020-05-03). "A New Ladinian Nothosauroid (Sauropterygia) from Fuyuan, Yunnan Province, China" . Journal of Vertebrate Paleontology . 40 (3): e1789651. Bibcode : 2020JVPal..40E9651S . doi : 10.1080/02724634.2020.1789651 . ISSN   0272-4634 . S2CID   227241106 . ^ Li, C.; Wu, X. C.; Zhao, L. J.; Sato, T.; Wang, L. T. (2012). "A new archosaur (Diapsida, Archosauriformes) from

3306-420: The tip of the lower jaws and two pairs along the upper jaws. They together form a protruding, beak-like crushing and grinding mechanism, comparable to the incisor teeth of rodents and lagomorphs (hence the name "rabbit fish"). Chimaera teeth are unique among vertebrates, due to their mode of mineralization. Most of each plate is formed by relatively soft osteodentin , but the active edges are supplemented by

3364-413: The water column. Chimaera reproduction resembles that of sharks in some ways: males employ claspers for internal fertilization of females and females lay eggs within spindle -shaped, leathery egg cases . Unlike sharks, male chimaeras have retractable sexual appendages (known as tentacula) to assist mating. The frontal tentaculum, a bulbous rod which extends out of the forehead, is used to clutch

#660339