The Callovian-Oxfordian Boundary In
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Or Early Callovian) Ammonites from Alaska and Montana
Jurassic (Bathonian or Early Callovian) Ammonites From Alaska and Montana By RALPH W. IMLAY SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 374-C Descr$tions and illustrations of ctphalopods of possible late Middle Jurasric (Bathonian) age UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1962 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. CONTENTS Page Page C- 1 Age of the faunas-Continued C- 1 Callovian versus Bathonian in Greenland- - - - _ - - _ - - C-2 Callovian versus Bathonian in Alaska and Montana- -- - Stratigraphic summary- __ --______ _ - - - -- - ---.- -- -.- - - C-2 Paleogeographic considerations- - -_-- -- ---- ---- Cook Inlet region, Alaska -______--------.-.--..--c-2 Summation of the evidence- - - _._ _ - _ _ - - - - - - - - - - - - Iniskin Peninsula-_-_______----.--------~.--C-2 Comparisons with other faunas---------___----------- Peninsula north of Chinitna Bay----- __._ _ _._ - C-3 \Vestern interior of Canada- - - -- -- -____------- --- Talkeetna Mountains ----___-_ - - -- ---- - - -- - -- C-3 Arctic region-_-_---___-_----------------------- Western Montana- - -----__-----------------.---C-5 other regions--__-__-____----------------------- Rocky Mountain front north of the Sun River- (2-5 Geographic distribution ___-___ --- - ---------- ------ -- - Drummond area--- ---_____ _--- -- -.-- ---- -- - C-10 Summary of results- --_-____-_----_---_-_----------- Age ofthe faunas-----------_----------------------- GI0 Systematic descriptions--_ _ _ - _ - - - - - - - - - - - - - - - - - - - - - - - Evidence from Alaska---____________--------------C-10 Literature cited _-_-_---______----------------------- Evidence from Montana --_-_____ --- - - -- .--- --- - - C-12 Index---__--___-_-_------------------------------- ILLUSTRATIONS [Plates 1-3 follow index] PLATE 1. Holcophylloceras, Oecotraustes (Paroecotraustes) ?, and Arctocephalites (Cranocephalites). 2. -
Callovian (Middle Jurassic) Dinoflagellate Cysts from the Algarve Basin, Southern
1 Callovian (Middle Jurassic) dinoflagellate cysts from the Algarve Basin, southern 2 Portugal 3 4 Marisa E.N. Borges a,b, James B. Riding c,*, Paulo Fernandes a, Vasco Matos a, Zélia 5 Pereira b 6 7 a CIMA - Centro de Investigação Marinha e Ambiental, Universidade do Algarve, 8 Campus de Gambelas, 8005-139 Faro, Portugal 9 b LNEG-LGM, Rua da Amieira, 4465-965 S. Mamede Infesta, Portugal 10 c British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 11 5GG, UK 12 13 * Corresponding author. Tel.: +44(0)115 9363447 14 E-mail addresses: [email protected] (M.E.N. Borges), [email protected] (J.B. 15 Riding), [email protected] (P. Fernandes), [email protected] (V. Matos), 16 [email protected] (Z. Pereira). 17 18 ABSTRACT 19 The palynology of three Callovian (Middle Jurassic) limestone-marl successions from 20 the Algarve Basin in southern Portugal was studied. These localities are Baleeira 21 Harbour, Mareta Beach and Telheiro Quarry; they provide a composite succession, tied 1 22 to ammonite zones, through the Lower, Middle and Upper Callovian from the western 23 and eastern subbasins of the Algarve Basin. The three sections generally yielded 24 relatively abundant marine and continental palynofloras. Diversity is low to moderate 25 and the dinoflagellate cyst associations are dominated by Ctenidodinium spp., the 26 Ellipsoidictyum/Valensiella group, Gonyaulacysta jurassica subsp. adecta, 27 Korystocysta spp., Meiourogonyaulax spp., Pareodinia ceratophora, Sentusidinium 28 spp., Surculosphaeridium? vestitum and Systematophora spp. Some intra-Callovian 29 marker bioevents were recorded; these include the range bases of Ctenidodinium 30 ornatum, Gonyaulacysta eisenackii, Korystocysta pachyderma, Mendicodinium 31 groenlandicum, Rigaudella spp. -
Upper Bajocian– Callovian) of the Polish Jura Chain and Holy Cross Mountains (South-Central Poland)
1661-8726/07/010153-12 Swiss j. geosci. 100 (2007) 153–164 DOI 10.1007/s00015-007-1207-3 Birkhäuser Verlag, Basel, 2007 A diverse crinoid fauna from the Middle Jurassic (Upper Bajocian– Callovian) of the Polish Jura Chain and Holy Cross Mountains (south-central Poland) MARIUSZ A. SALAMON*& MICHA¸ ZATO¡ Key words: crinoids, Middle Jurassic, Poland, palaeobiogeography, taphonomy, epibiontism ABSTRACT ZUSAMMENFASSUNG A systematic account of a diverse crinoid fauna from the Middle Jurassic Aus mitteljurassischen (Bajocian–Callovian) Sedimenten des südlichen (Upper Bajocian–Callovian) of the Polish Jura Chain and Holy Cross Moun- Zentralpolens (Krakow–Cz´stochowa Hochland und Heilig-Kreuz Gebirge) tains (south-central Poland) is presented. The description is supplemented wird eine diverse Crinoidenfauna systematisch beschrieben und stratigra- with a list of all crinoid species found hitherto in the Tatra Mountains and the phisch eingestuft. Die Beschreibung wird durch eine Zusammenstellung sämt- Pieniny Klippen Belt (Poland), which were a part of the northern margin of licher Crinoiden-Spezies ergänzt, die bislang im Tatra-Gebirge und im Pieniny the Tethys during Middle Jurassic time. Balanocrinus hessi seems to be en- Klippen-Gürtel gefunden wurden. Beide Regionen waren während des Mitt- demic and established its own population in the epicontinental sea. Other leren Jura Teil des Nordrandes der Tethys. Balanocrinus hessi bildete eigen- stalked crinoids entered from the Tethys through the East-Carpathian Gate or ständige Populationen in diesem epikontinentalen Meeresbereich und scheint from a westerly way, and constitute a typical Mediterranean fauna. Stemless endemisch gewesen zu sein. Andere gestielte Crinoiden drangen aus der forms are regarded to be unsuccessful immigrants. -
Ammonites from Bathonian and Callovian (Middle Jurassic)
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Universität München: Elektronischen Publikationen 253 Zitteliana 89 Ammonites from Bathonian and Callovian (Middle Jurassic) North of Damghan, Paläontologie Bayerische EasternGeoBio- Alborz, North Iran & Geobiologie Staatssammlung Center LMU München LMU München für Paläontologie und Geologie Kazem Seyed-Emami1* & Ahmad Raoufian2 München, 01.07.2017 1School of Mining Engineering, University College of Engineering, University of Tehran, Manuscript received P.O. Box 11365-4563, Tehran, Iran 2 26.09.2016; revision Daneshvar Center, Farhangian University, Neyshapour, Iran accepted 30.10.2016 *Corresponding author; E-mail: [email protected] ISSN 0373-9627 ISBN 978-3-946705-00-0 Zitteliana 89, 253–270. Abstract The following Middle Jurassic ammonite families (subfamilies) are described from the Dalichai Formation north of Damghan (eastern Alborz), some of them for the first time: Phylloceratidae, Lytoceratidae, Oppeliidae (Hecticoceratinae), Stephanoceratidae (Cadomitinae), Tulitidae and Reineckeiidae. The fauna is typically Northwest-Tethyan and closely related to Central Europe (Subboreal – Submediterra- nean Provinces). Key words: Ammonites, Dalichai Formation, Middle Jurassic, Alborz, Iran Zusammenfassung Aus der Dalichai Formation nördlich von Damghan (Ostalborz) werden einige mitteljurassische Ammoniten, teils zum ersten Mal, beschrieben. Folgende Familien und Unterfamilien sind vertreten: Phylloceratidae, Lytoceratidae, Oppeliidae (Hecticoceratinae), Steph- anoceratidae (Cadomitinae), Tulitidae und Reineckeiidae. Die Fauna ist typisch für die Nordwest-Tethys und zeigt enge Beziehungen zu Zentraleuropa (Subboreale und Submediterrane Faunenprovinz). Schlüsselwörter: Ammoniten, Dalichai Formation, Mittlerer Jura, Alborz, Iran Introduction the frame of a MSc. thesis. For the present study, a new section nearby was chosen and collections The present study is a continuation of a larger re- were made by A. -
Pliensbachian Nannofossils from Kachchh: Implications on the Earliest Jurassic Transgressive Event on the Western Indian Margin
53 he A Rei Series A/ Zitteliana An International Journal of Palaeontology and Geobiology Series A /Reihe A Mitteilungen der Bayerischen Staatssammlung für Paläontologie und Geologie 53 An International Journal of Palaeontology and Geobiology München 2013 Zitteliana Zitteliana A 53 (2013) 105 Pliensbachian nannofossils from Kachchh: Implications on the earliest Jurassic transgressive event on the western Indian margin Jyotsana Rai1 & Sreepat Jain2* Zitteliana A 53, 105 – 120 1Birbal Sahni Institute of Palaeobotany, 53 University Road, 226007, Lucknow, India München, 31.12.2013 2DG–2, Flat no. 52D, SFS Flats, Vikas Puri, New Delhi, 110018, India Manuscript received *Author for correspondence and reprint requests: E-mail: [email protected] 05.04.2013; revision accepted 16.11.2013 ISSN 1612 - 412X Abstract The oldest rocks within the Kachchh Basin belong to the sediments of Kaladongar Formation exposed in Kuar Bet, Pachchham Island (western India). The Formation’s lowest unit, the Dingi Hill Member has yielded a moderately diversified calcareous nannofossil assembla- ge that includes the marker species of Lotharingius contractus and Triscutum sullivanii of late Early Aalenian age associated with reworked species of Biscutum finchii, Bussonius prinsii, Crucirhabdus primulus, Crepidolithus pliensbachensis, Discorhabdus criotus and D. striatus suggesting an age spanning NJ4a to NJ7 Zones (Early Pliensbachian, Tethyan ammonite Jamesoni Zone to Middle Toarcian, Variabilis Zone). Additionally, samples from four other Kachchh domal localities (Kachchh Mainland: Jara, Jumara and Habo and the Island belt, Waagad) have also yielded reworked Pliensbachian-Toarcian age (~183 Ma) nannotaxa viz. Crepidolithus granulatus, Diductius constans, Mazaganella protensa, Mitrolithus elegans, Parhabdolithus liasicus, Similiscutum orbiculus, and Triscutum tiziense. This nannotaxa age is much earlier than the ammonite-based Earliest Bajocian date (~171.6 Ma) based on the presence of ammonite Calliphylloceras hetero- phylloides (Oppel). -
GEOLOGIC TIME SCALE V
GSA GEOLOGIC TIME SCALE v. 4.0 CENOZOIC MESOZOIC PALEOZOIC PRECAMBRIAN MAGNETIC MAGNETIC BDY. AGE POLARITY PICKS AGE POLARITY PICKS AGE PICKS AGE . N PERIOD EPOCH AGE PERIOD EPOCH AGE PERIOD EPOCH AGE EON ERA PERIOD AGES (Ma) (Ma) (Ma) (Ma) (Ma) (Ma) (Ma) HIST HIST. ANOM. (Ma) ANOM. CHRON. CHRO HOLOCENE 1 C1 QUATER- 0.01 30 C30 66.0 541 CALABRIAN NARY PLEISTOCENE* 1.8 31 C31 MAASTRICHTIAN 252 2 C2 GELASIAN 70 CHANGHSINGIAN EDIACARAN 2.6 Lopin- 254 32 C32 72.1 635 2A C2A PIACENZIAN WUCHIAPINGIAN PLIOCENE 3.6 gian 33 260 260 3 ZANCLEAN CAPITANIAN NEOPRO- 5 C3 CAMPANIAN Guada- 265 750 CRYOGENIAN 5.3 80 C33 WORDIAN TEROZOIC 3A MESSINIAN LATE lupian 269 C3A 83.6 ROADIAN 272 850 7.2 SANTONIAN 4 KUNGURIAN C4 86.3 279 TONIAN CONIACIAN 280 4A Cisura- C4A TORTONIAN 90 89.8 1000 1000 PERMIAN ARTINSKIAN 10 5 TURONIAN lian C5 93.9 290 SAKMARIAN STENIAN 11.6 CENOMANIAN 296 SERRAVALLIAN 34 C34 ASSELIAN 299 5A 100 100 300 GZHELIAN 1200 C5A 13.8 LATE 304 KASIMOVIAN 307 1250 MESOPRO- 15 LANGHIAN ECTASIAN 5B C5B ALBIAN MIDDLE MOSCOVIAN 16.0 TEROZOIC 5C C5C 110 VANIAN 315 PENNSYL- 1400 EARLY 5D C5D MIOCENE 113 320 BASHKIRIAN 323 5E C5E NEOGENE BURDIGALIAN SERPUKHOVIAN 1500 CALYMMIAN 6 C6 APTIAN LATE 20 120 331 6A C6A 20.4 EARLY 1600 M0r 126 6B C6B AQUITANIAN M1 340 MIDDLE VISEAN MISSIS- M3 BARREMIAN SIPPIAN STATHERIAN C6C 23.0 6C 130 M5 CRETACEOUS 131 347 1750 HAUTERIVIAN 7 C7 CARBONIFEROUS EARLY TOURNAISIAN 1800 M10 134 25 7A C7A 359 8 C8 CHATTIAN VALANGINIAN M12 360 140 M14 139 FAMENNIAN OROSIRIAN 9 C9 M16 28.1 M18 BERRIASIAN 2000 PROTEROZOIC 10 C10 LATE -
The Callovian Unconformity and the Ophiolite Obduction Onto the Pelagonian Carbonate Platform of the Internal Hellenides
Δελτίο της Ελληνικής Γεωλογικής Εταιρίας, τόμος L, σελ. 144-152 Bulletin of the Geological Society of Greece, vol. L, p. 144-152 Πρακτικά 14ου Διεθνούς Συνεδρίου, Θεσσαλονίκη, Μάιος 2016 Proceedings of the 14th International Congress, Thessaloniki, May 2016 THE CALLOVIAN UNCONFORMITY AND THE OPHIOLITE OBDUCTION ONTO THE PELAGONIAN CARBONATE PLATFORM OF THE INTERNAL HELLENIDES Scherreiks R.1, Meléndez G.2, Bouldagher-Fadel M.3, Fermeli G.4 and Bosence D.5 1Bayerische Staaatssammlung, Department of Geology, University of Munich, Luisenstr. 33, 80333 Munich, Germany, [email protected] 2Departamento de Geologia (Paleontologia), Universidad de Zaragoza, 50009 Saragossa, Spain, [email protected] 3Earth Sciences, University College London, Gower Street, London WC1E6BT, UK, [email protected] 4Department of Historical Geology and Paleontology, University of Athens, Panepistimioupolis, Zographou, 15784 Athens, Greece, [email protected] 5Department of Earth Sciences, Royal Holloway University of London, Egham TW20 0EX, UK, [email protected] Abstract The carbonate-platform-complex and the oceanic formations of the central Pelagonian zone of the Hellenides evolved in response to a sequence of plate-tectonic episodes of ocean spreading, plate convergence and ophiolite obduction. The bio- stratigraphies of the carbonate platform and the oceanic successions, show that the Triassic-Early Jurassic platform was coeval with an ocean where pillow basalts and radiolarian cherts were being deposited. After convergence began during late Early- Jurassic - Middle Jurassic time, the oceanic leading edge of the Pelagonian plate was subducted beneath the leading edge of the oceanic, overriding plate. The platform subsided while a supra-subduction, volcanic-island-arc evolved. -
The Jurassic (Pliensbachian to Oxfordian) Palynology of the Algarve Basin and the Carrapateira Outlier, Southern Portugal
1 The Jurassic (Pliensbachian to Kimmeridgian) palynology of the Algarve Basin and the 2 Carrapateira outlier, southern Portugal 3 4 Marisa E.N. Borges a,b, James B. Riding c*, Paulo Fernandes a, Zélia Pereira b 5 6 a CIMA - Centro de Investigação Marinha e Ambiental. Universidade do Algarve, 7 Campus de Gambelas, 8005-139 Faro, Portugal 8 b LNEG-LGM, Rua da Amieira, 4465-965 S. Mamede Infesta, Portugal 9 c British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 10 5GG, UK 11 12 * Corresponding author. Tel.: +44(0)115 9363447. 13 E-mail addresses: [email protected] (M.E.N. Borges), [email protected] (J.B. 14 Riding), [email protected] (P. Fernandes), [email protected] (Z. Pereira). 15 16 ABSTRACT 17 The palynology of the Jurassic (Upper Pliensbachian to Lower Kimmeridgian) 18 fill of the Algarve Basin and the Carrapateira outlier, southern Portugal was 19 investigated. Samples were collected from Armação Nova Bay, Mareta Beach, Cilheta 20 Beach and the Carrapateira outlier. At Armação Nova Bay the Upper Pliensbachian- 21 Lower Toarcian succession proved barren, or yielded sparse, non age-diagnostic 22 palynomorphs. Dinoflagellate cysts are confined to the Upper Bajocian to Upper 23 Callovian sedimentary rocks exposed at Mareta and Cilheta beaches and the Lower 24 Kimmeridgian strata of the Carrapateira outlier. At Mareta Beach, the Upper Bajocian, 25 Bathonian and Callovian produced relatively low to moderate diversity dinoflagellate 26 cyst assemblages. Several key bioevents confirm the Bathonian and Callovian ages of 27 the succession; no age-significant Late Bajocian bioevents were noted. -
The First Record of Freshwater Plesiosaurian from the Middle
Gao et al. Journal of Palaeogeography (2019) 8:27 https://doi.org/10.1186/s42501-019-0043-5 Journal of Palaeogeography ORIGINALARTICLE Open Access The first record of freshwater plesiosaurian from the Middle Jurassic of Gansu, NW China, with its implications to the local palaeobiogeography Ting Gao, Da-Qing Li* , Long-Feng Li and Jing-Tao Yang Abstract Plesiosaurs are one of the common groups of aquatic reptiles in the Mesozoic, which mainly lived in marine environments. Freshwater plesiosaurs are rare in the world, especially from the Jurassic. The present paper reports the first freshwater plesiosaur, represented by four isolated teeth from the Middle Jurassic fluviolacustrine strata of Qingtujing area, Jinchang City, Gansu Province, Northwest China. These teeth are considered to come from one individual. The comparative analysis of the corresponding relationship between the body and tooth sizes of the known freshwater plesiosaur shows that Jinchang teeth represent a small-sized plesiosaurian. Based on the adaptive radiation of plesiosaurs and the palaeobiogeographical context, we propose a scenario of a river leading to the Meso-Tethys in the Late Middle Jurassic in Jinchang area, which may have provided a channel for the seasonal migration of plesiosaurs. Keywords: Freshwater plesiosaur, Middle Jurassic, Jinchang, Gansu Province, Palaeobiogeography 1 Introduction Warren 1980;Satoetal.2003; Kear 2012). Up to now, Plesiosaurs are one of the most familiar groups of Mesozoic the taxonomic affinities of most freshwater plesio- marine reptiles, which mainly lived in marine environ- saurs have remained unclear; some of them are re- ments. The records of plesiosaurs in non-marine deposits ferred to Plesiosauroidea (Cruickshank and Fordyce are sparse in comparison to those from marine sediments. -
Paleogeographic Maps Earth History
History of the Earth Age AGE Eon Era Period Period Epoch Stage Paleogeographic Maps Earth History (Ma) Era (Ma) Holocene Neogene Quaternary* Pleistocene Calabrian/Gelasian Piacenzian 2.6 Cenozoic Pliocene Zanclean Paleogene Messinian 5.3 L Tortonian 100 Cretaceous Serravallian Miocene M Langhian E Burdigalian Jurassic Neogene Aquitanian 200 23 L Chattian Triassic Oligocene E Rupelian Permian 34 Early Neogene 300 L Priabonian Bartonian Carboniferous Cenozoic M Eocene Lutetian 400 Phanerozoic Devonian E Ypresian Silurian Paleogene L Thanetian 56 PaleozoicOrdovician Mesozoic Paleocene M Selandian 500 E Danian Cambrian 66 Maastrichtian Ediacaran 600 Campanian Late Santonian 700 Coniacian Turonian Cenomanian Late Cretaceous 100 800 Cryogenian Albian 900 Neoproterozoic Tonian Cretaceous Aptian Early 1000 Barremian Hauterivian Valanginian 1100 Stenian Berriasian 146 Tithonian Early Cretaceous 1200 Late Kimmeridgian Oxfordian 161 Callovian Mesozoic 1300 Ectasian Bathonian Middle Bajocian Aalenian 176 1400 Toarcian Jurassic Mesoproterozoic Early Pliensbachian 1500 Sinemurian Hettangian Calymmian 200 Rhaetian 1600 Proterozoic Norian Late 1700 Statherian Carnian 228 1800 Ladinian Late Triassic Triassic Middle Anisian 1900 245 Olenekian Orosirian Early Induan Changhsingian 251 2000 Lopingian Wuchiapingian 260 Capitanian Guadalupian Wordian/Roadian 2100 271 Kungurian Paleoproterozoic Rhyacian Artinskian 2200 Permian Cisuralian Sakmarian Middle Permian 2300 Asselian 299 Late Gzhelian Kasimovian 2400 Siderian Middle Moscovian Penn- sylvanian Early Bashkirian -
2009 Geologic Time Scale Cenozoic Mesozoic Paleozoic Precambrian Magnetic Magnetic Bdy
2009 GEOLOGIC TIME SCALE CENOZOIC MESOZOIC PALEOZOIC PRECAMBRIAN MAGNETIC MAGNETIC BDY. AGE POLARITY PICKS AGE POLARITY PICKS AGE PICKS AGE . N PERIOD EPOCH AGE PERIOD EPOCH AGE PERIOD EPOCH AGE EON ERA PERIOD AGES (Ma) (Ma) (Ma) (Ma) (Ma) (Ma) (Ma) HIST. HIST. ANOM. ANOM. (Ma) CHRON. CHRO HOLOCENE 65.5 1 C1 QUATER- 0.01 30 C30 542 CALABRIAN MAASTRICHTIAN NARY PLEISTOCENE 1.8 31 C31 251 2 C2 GELASIAN 70 CHANGHSINGIAN EDIACARAN 2.6 70.6 254 2A PIACENZIAN 32 C32 L 630 C2A 3.6 WUCHIAPINGIAN PLIOCENE 260 260 3 ZANCLEAN 33 CAMPANIAN CAPITANIAN 5 C3 5.3 266 750 NEOPRO- CRYOGENIAN 80 C33 M WORDIAN MESSINIAN LATE 268 TEROZOIC 3A C3A 83.5 ROADIAN 7.2 SANTONIAN 271 85.8 KUNGURIAN 850 4 276 C4 CONIACIAN 280 4A 89.3 ARTINSKIAN TONIAN C4A L TORTONIAN 90 284 TURONIAN PERMIAN 10 5 93.5 E 1000 1000 C5 SAKMARIAN 11.6 CENOMANIAN 297 99.6 ASSELIAN STENIAN SERRAVALLIAN 34 C34 299.0 5A 100 300 GZELIAN C5A 13.8 M KASIMOVIAN 304 1200 PENNSYL- 306 1250 15 5B LANGHIAN ALBIAN MOSCOVIAN MESOPRO- C5B VANIAN 312 ECTASIAN 5C 16.0 110 BASHKIRIAN TEROZOIC C5C 112 5D C5D MIOCENE 320 318 1400 5E C5E NEOGENE BURDIGALIAN SERPUKHOVIAN 326 6 C6 APTIAN 20 120 1500 CALYMMIAN E 20.4 6A C6A EARLY MISSIS- M0r 125 VISEAN 1600 6B C6B AQUITANIAN M1 340 SIPPIAN M3 BARREMIAN C6C 23.0 345 6C CRETACEOUS 130 M5 130 STATHERIAN CARBONIFEROUS TOURNAISIAN 7 C7 HAUTERIVIAN 1750 25 7A M10 C7A 136 359 8 C8 L CHATTIAN M12 VALANGINIAN 360 L 1800 140 M14 140 9 C9 M16 FAMENNIAN BERRIASIAN M18 PROTEROZOIC OROSIRIAN 10 C10 28.4 145.5 M20 2000 30 11 C11 TITHONIAN 374 PALEOPRO- 150 M22 2050 12 E RUPELIAN -
Diversification of Insects Since the Devonian
www.nature.com/scientificreports OPEN Diversifcation of insects since the Devonian: a new approach based on morphological disparity of Received: 18 September 2017 Accepted: 12 February 2018 mouthparts Published: xx xx xxxx Patricia Nel1,2, Sylvain Bertrand2 & André Nel1 The majority of the analyses of the evolutionary history of the megadiverse class Insecta are based on the documented taxonomic palaeobiodiversity. A diferent approach, poorly investigated, is to focus on morphological disparity, linked to changes in the organisms’ functioning. Here we establish a hierarchy of the great geological epochs based on a new method using Wagner parsimony and a ‘presence/ absence of a morphological type of mouthpart of Hexapoda’ dataset. We showed the absence of major rupture in the evolution of the mouthparts, but six epochs during which numerous innovations and few extinctions happened, i.e., Late Carboniferous, Middle and Late Triassic, ‘Callovian-Oxfordian’, ‘Early’ Cretaceous, and ‘Albian-Cenomanian’. The three crises Permian-Triassic, Triassic-Jurassic, and Cretaceous-Cenozoic had no strong, visible impact on mouthparts types. We particularly emphasize the origination of mouthparts linked to nectarivory during the Cretaceous Terrestrial Revolution. We also underline the origination of mouthparts linked to phytophagy during the Middle and the Late Triassic, correlated to the diversifcation of the gymnosperms, especially in relation to the complex ‘fowers’ producing nectar of the Bennettitales and Gnetales. During their ca. 410 Ma history, hexapods have evolved morphologically to adapt in a continuously changing world, thereby resulting in a unique mega-biodiversity1. Age-old questions2–4 about insects’ macroevolution now- adays receive renewed interest thanks to the remarkable recent improvements in data and methods that allow incorporating full data, phylogenomic trees besides fossil record5–9.