Tesis De Grado Valentina Blandon 201511522

Total Page:16

File Type:pdf, Size:1020Kb

Tesis De Grado Valentina Blandon 201511522 Reconstrucción científica del Macizo Devónico de Floresta, ilustrada en un diorama. Por Valentina Blandón Hurtado 201511522 Director Dr. Leslie F. Noè Uniandes Co director Dr. Jaime Reyes Abril S.G.C. Universidad de los Andes Facultad de Ciencias Departamento de Geociencias Bogotá, Colombia Noviembre 2019 Leslie F. Noè Jaime A. Reyes Valentina Blandón Hurtado II Tabla de contenido Dedicación .................................................................................................................................V Agradecimiento ..........................................................................................................................V Resumen ...................................................................................................................................VI Abstract ...................................................................................................................................VII Introducción ................................................................................................................................1 Metodología y Materiales ...........................................................................................................5 Resultados y Discusiones ...........................................................................................................7 Devónico Inferior – Formación El Tibet ....................................................................................7 Descripción organismos Formación El Tibet .........................................................................8 Devónico Medio – Formación Floresta ....................................................................................11 Descripción especies de la Formación Floresta ...................................................................12 1.Braquiópodos ...............................................................................................................12 I. Leptaena boyaca .................................................................................................12 II.Brachyspirifer palmerae ....................................................................................14 III.Chonetes ...........................................................................................................15 2. Antozoos .....................................................................................................................16 I. Tetracoralarios ..................................................................................................16 3. Crinoideos ...................................................................................................................17 I. Bogotacrinus scheibei .......................................................................................17 4. Bryozoa .......................................................................................................................19 I. Fenestella sp ......................................................................................................19 5. Molusca....................................................................................................................... 20 I. Palaeoneilo sp ...................................................................................................20 III II. Actinopteria sp ..................................................................................................21 III.Gasterópodos y cefalópodos .............................................................................23 6. Trilobites .....................................................................................................................24 I. Phacops .............................................................................................................24 II. Dalmanites ........................................................................................................25 Devónico Superior - Formación Cuche ....................................................................................27 Descripción especies Formación Cuche ..............................................................................28 1. Quitinozoos. ................................................................................................................28 2. Peces ...........................................................................................................................29 I. Antiarcos ...........................................................................................................29 II. Artrodiros ..........................................................................................................30 III.Porolepiformes.................................................................................................. 31 4. Plantas. ........................................................................................................................33 I. Archaeopteris. ...................................................................................................33 Conclusiones .............................................................................................................................35 Propuesta para infogramas ........................................................................................................36 Referencias ...............................................................................................................................37 IV Dedicación Dedico este Proyecto de tesis a las personas que más amo: a mis padres Rigoberto y Gladys y a mi hermana Vannessa. Agradezco a ellos por su incondicional apoyo y amor que me permite ponerme retos y no dudar de mis capacidades, necesarias para completar esta retadora etapa, ya que siempre me dieron el cariño y las palabras alentadoras para que yo misma creyera que soy capaz con todos los retos que la vida me pone. Quiero también agradecer a mi amiga Va- nessa Rodríguez, quien me acompañó durante largas jornadas de estudio y me animaba a mantenerme siempre enfocada. Agradecimiento Agradezco a los profesores Leslie Noè y Jaime Reyes por siempre resolver mis dudas, por su atención y apoyo incondicional y por brindarme la mejor asesoría gracias a su increíble expe- riencia y espíritu de servicio. Asimismo, agradezco a mis padres y hermana por motivarme para lograr la exitosa culminación de este proyecto y por respaldarme siempre, sobre todo en momentos críticos a lo largo de mis estudios. De igual manera agradezco a Marcela Gómez del Servicio Geológico Colombiano, quien siempre estuvo atenta a cualquier duda que tuviera y dio las pautas para mi proyecto. También doy gracias a Andrés, ya que por sus capacidades artísticas mi proyecto se va a lograr ver reflejado de manera innovadora para que la informa- ción científica llegue al público en general. V Resumen El objetivo del presente trabajo es Desarrollar el marco teórico científico de un diorama inter- activo, del Devónico Inferior, Medio y Superior del Macizo de Floresta, que permita una di- vulgación eficiente a públicos en general, reconstruyendo la paleofauna, paleoflora y paleo- ambientes del Macizo de Floresta, Boyacá. Para lograr esto se va a reconocer la fauna y flora presente en Floresta en el periodo Devónico en tres unidades, en la época Inferior, Medio y Superior. De igual manera se va a generar la parte teórica de un diorama interactivo para que posteriormente diseñadores de la Universidad Nacional construyan el diseño del diorama, res- petando la escala y características de la fauna y flora del Devónico. Por otra parte, se van a obtener los elementos principales de una infografía para cada una de las tres épocas del De- vónico que complemente el diorama llevado acabo, teniendo en cuenta qué está dirigido al público y con las indicaciones dadas por el Museo Geológico Nacional José Royo Gómez. VI Abstract The objective of this paper is to develop the theoretical scientific framework of an interactive diorama, of the Lower, Middle and Upper Devonian of the Massif of Floresta, that allows an efficient dissemination to the general public, reconstructing the paleofauna, paleoflora and paleoenvironment of the Massif of Floresta, Boyacá. To achieve this, the fauna and flora pre- sent in Floresta in the Devonian period will be recognized in three units, in the Lower, Middle and Upper Period. In the same way, the theoretical part of an interactive diorama will be gene- rated so that later designers of the National University can design the diorama, respecting the scale and characteristics of the fauna and flora of the Devonian. On the other hand, there will be obtained the main elements of an infographic for each of the three epochs of Devonian that complements the diorama carried out, taking into account what is addressed to the public and with the indications given by the National Geological Museum José Royo Gómez. VII VIII IX Introducción El Devónico es un periodo geológico con un inicio hace 410 millones de años y culminó hace 360 millones de años atrás (Cohen et al., 2018). Geológicamente las rocas del Devónico en Colombia se exponen principalmente en la Cordillera Oriental y la Sierra de Perijá, con lito- logías dominantes de shales, limolitas y areniscas finas y medias, y un espesor variable de 200 m a 800 m (Mojica y Virraroel, 1984). En el Macizo de Floresta la base del Devónico es una inconformidad angular sobre rocas ígneas y metamórficas del basamento metamórfico del Macizo de Floresta. Continuando, su tope es una conformidad con las rocas Jurásicas, cabe
Recommended publications
  • JVP 26(3) September 2006—ABSTRACTS
    Neoceti Symposium, Saturday 8:45 acid-prepared osteolepiforms Medoevia and Gogonasus has offered strong support for BODY SIZE AND CRYPTIC TROPHIC SEPARATION OF GENERALIZED Jarvik’s interpretation, but Eusthenopteron itself has not been reexamined in detail. PIERCE-FEEDING CETACEANS: THE ROLE OF FEEDING DIVERSITY DUR- Uncertainty has persisted about the relationship between the large endoskeletal “fenestra ING THE RISE OF THE NEOCETI endochoanalis” and the apparently much smaller choana, and about the occlusion of upper ADAM, Peter, Univ. of California, Los Angeles, Los Angeles, CA; JETT, Kristin, Univ. of and lower jaw fangs relative to the choana. California, Davis, Davis, CA; OLSON, Joshua, Univ. of California, Los Angeles, Los A CT scan investigation of a large skull of Eusthenopteron, carried out in collaboration Angeles, CA with University of Texas and Parc de Miguasha, offers an opportunity to image and digital- Marine mammals with homodont dentition and relatively little specialization of the feeding ly “dissect” a complete three-dimensional snout region. We find that a choana is indeed apparatus are often categorized as generalist eaters of squid and fish. However, analyses of present, somewhat narrower but otherwise similar to that described by Jarvik. It does not many modern ecosystems reveal the importance of body size in determining trophic parti- receive the anterior coronoid fang, which bites mesial to the edge of the dermopalatine and tioning and diversity among predators. We established relationships between body sizes of is received by a pit in that bone. The fenestra endochoanalis is partly floored by the vomer extant cetaceans and their prey in order to infer prey size and potential trophic separation of and the dermopalatine, restricting the choana to the lateral part of the fenestra.
    [Show full text]
  • Middle Permian Brachiopods from Setamai, the Type Locality of The
    Sci. Rep., Niigata Univ., Ser. E(Geology), No. 16, 1-33, 2001 Middle Permian brachiopods from Setamai,the type locality of the Kanokura Formation,southern Kitakami Mountains, northeast Japan Jun-ichi TAZAWA* and Yosuke IBARAKI** Abstract A Middle Permian (Kubergandian-Murgabian) brachiopod fauna is described from the type section of the lower Kanokura Formation in the Setamai area, southern Kitakami Moun tains, northeast Japan. This fauna contains the following nine species: Transennatia gratiosa, Tyloplecta cf. yangzeensis, Waagenoconcha sp., Linoproductus cora, Cancrinella sp., Leptodus nobilis, Derbyia grandis, Derbyia nipponica and Spiriferella keilhavii. The Setamai fauna is characterized by the mixuture of both the Boreal and Tethyan elements. Key words: Boreal-Tethyan mixed fauna, brachiopods. Middle Permian, Setamai, southern Kitakami Mountains. Introduction The Permian brachiopod specimens described in this paper were collected by the authors and late Prof. M. Minato of Hokkaido University from nine localities in the Kanokurasawa and Kacchizawa valleys in the Setamai area, the type locahty of the lower part of the Kanokura Formation, southern Kitakami Mountains, northeast Japan (Figs. 1,2). The Middle Permian Kanokura Formation was named by Onuki (1937) as the Kanokura Stage, but Onuki (1956)later changed the name to 'formation' with the outcrops along the Kanokurasawa valley as its type section. The stratigraphy of the Kanokura Formation in the Setamai area was described and discussed in detail by Minato et al.(1954,1978,1979), Onuki (1956, 1969), Murata (1964), Saito (1966, 1968) and Choi (1973, 1976). In palaeontology, many species of fusulinaceans (Choi, 1973), corals (Minato, 1955; Minato and Kato, 1965), brachiopods (Hayasaka, 1953; Hayasaka and Minato, 1956; Minato and Nakamura, 1956; * Department of Geology, Faculty of Science, Niigata University, Niigata 950-2181, Japan ** Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan (Manuscript received 24 November, 2(XX); accepted 21 December, 2000) J.
    [Show full text]
  • University of Michigan University Library
    CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY UNIVERSITY OF MICHIGAN VOL. XI NO.6, pp. 101-157 (12 pk., 1 map) MARCH25, 1953 TRILOBITES OF THE DEVONIAN TRAVERSE GROUP OF MICHIGAN BY ERWIN C. STUMM UNIVERSITY OF MICHIGAN PRESS ANN ARBOR CONTMBUTIONS FROM THE MUSEUM OF PALEONTOLOGY UNIVERSITY OF MICHIGAN MUSEUM OF PALEONTOLOGY Director: LEWIS B. KELLUM The series of contributions from the Museum of Paleontology is a medium for the publication of papers based chiefly upon the collections in the Museum. When the number of pages issued is sufficient to make a volume, a title page and a table of contents will be sent to libraries on the mailing list, and also to individuals upon request. Correspondence should be directed to the University of Michigan Press. A list of the separate papers in Volumes II-IX will be sent upon request. VOL. I. The Stratigraphy and Fauna of the Hackberry Stage of the Upper Devonian, by C. L. Fenton and M. A. Fenton. Pages xi+260. Cloth. $2.75. VOL. 11. Fourteen papers. Pages ix+240. Cloth. $3.00. Parts sold separately in paper covers. VOL. 111. Thirteen papers. Pages viii+275. Cloth. $3.50. Parts sold separately in paper covers. VOL. IV. Eighteen papers. Pages viiif295. Cloth. $3.50. Parts sold separately in paper covers, VOL. V. Twelve papers. Pages viii+318. Cloth. $3.50. Parts sold separately in paper covers. VOL. VI. Ten papers. Pages vii+336. Paper covers. $3.00. Parts sold separately. VOLS. VII-IX. Ten numbers each, sold separately. (Continued on inside back cover) VOL.
    [Show full text]
  • Moscow Formation) in Erie County , Ny
    BIOSTRATIGRAPHY AND PALEOECOLO GY OF THE WINDOM SHALE MEMBER (MOSCOW FORMATION) IN ERIE COUNTY , NY. Carlton E. Brett) State University of New York at Buffalo INTRODUCTION The exposures of Hamilton strata along Lake Erie shore and in various creek beds in Erie County south of Buffalo a r e among the best- known and most thoroughly- studied Middle Devonian fossiliferous sequences in the world. The monumental studies of James Hall and A. W. Grabau (1898, 1899) provided a solid back­ ground for numerous later studies . Yet , in over a century of study, many biostratigraphic and paleoecological problems remain unlnvestigated . Recently , an exceptionally large and complete section of the Windom Shale (Moscow Formation) has been exposed 1n the shale quarries of Penn Dixie Cement Co . near Bayview , N. Y, This outcrop provides an excellent opportunity for detailed study of the fossil horizons of this upper Hamilton unit . Discovery of several new and little- known horizons at this quarry have led to the present restudy of biostratigraphy of the Windom in Erie County . STRATIGRAPHY From its type locality at Smokes Creek near Windom , Erie County N. Y., the Windom Member can be traced eastward nearly 200 miles to the vicinity of Skaneateles Lake (see Rickard, 1964) where the unit becomes sandy and grades into the Cooperstown shales and sandstones . Over mos t of this interval the Windom is a grey , calcareous shale . It is fossiliferous throughout most of its thickness and contains a characteristic IIMoscow Facies" suite fossils. In Erie County the Windom ranges from 9 to 50 ft . in thickness and is composed dominantly of soft, fissile medium- gray shale with thin bands of fossiliferous limestone .
    [Show full text]
  • Instituto De Geociências Revisão Sistemática E
    UNIVERSIDADE DE SÃO PAULO INSTITUTO DE GEOCIÊNCIAS REVISÃO SISTEMÁTICA E PALEOBIOGEOGRÁFICA DE TRILOBITAS PHACOPIDA (HOMALONOTIDAE E CALMONIIDAE) DO DEVONIANO DAS BACIAS DO PARNAÍBA E AMAZONAS, BRASIL Felipe van Enck Meira Tese apresentada ao Programa de Pós- Graduação em Geoquímica e Geotectônica do Instituto de Geociências da Universidade de São Paulo, como parte dos requisitos para a obtenção do título de doutor. Orientadora: Prof. Dra. Juliana de Moraes Leme TESE DE DOUTORAMENTO Programa de Pós-graduação em Geoquímica e Geotectônica São Paulo 2016 “Kites rise highest against the wind - not with it.” - Winston Churchill Agradecimentos Agradeço a Deus, por sempre iluminar o caminho durante esses anos de altos e baixos do Doutorado. Agradeço a Ele também por enviar dois verdadeiros anjos da guarda à minha vida – minha esposa Angela Faleiros van Enck Meira e meu filho, Thomas Faleiros van Enck Meira. Agradeço a meus pais, José Carlos e Sylvia, e à minha irmã, Patrícia, pelo apoio durante a jornada, ainda que à distância, por vezes. Sou grato aos meus sogros, Jair e Lucia, que sempre foram como verdadeiros pais e conselheiros. À FAPESP (Processo n° 2012/07075-3), pelo suporte financeiro, sem o qual o Doutorado não seria viável. À minha orientadora, Drª. Juliana de Moraes Leme, pela orientação, discussões e esclarecimentos pertinentes ao projeto. Ao Doutorando Fabio Carbonaro e ao Dr. Renato Ghilardi (UNESP-Bauru), pela parceria e por discussões importantes na realização do trabalho. À Drª. Niède Guidon (FUMDHAM), pelo empréstimo de fósseis da região de São João Vermelho (Piauí), estudados aqui. Sou grato às seguintes pessoas, por permitirem meu acesso às instituições para visita de acervos, e por sua disponibilidade, atenção e ajuda durante minha permanência: Bushra Hussaini (AMNH), Flávia Alessandra Figueiredo, Mônica de Medina Coeli, Dr.
    [Show full text]
  • Strophomenide and Orthotetide Silurian Brachiopods from the Baltic Region, with Particular Reference to Lithuanian Boreholes
    Strophomenide and orthotetide Silurian brachiopods from the Baltic region, with particular reference to Lithuanian boreholes PETRAS MUSTEIKIS and L. ROBIN M. COCKS Musteikis, P. and Cocks, L.R.M. 2004. Strophomenide and orthotetide Silurian brachiopods from the Baltic region, with particular reference to Lithuanian boreholes. Acta Palaeontologica Polonica 49 (3): 455–482. Epeiric seas covered the east and west parts of the old craton of Baltica in the Silurian and brachiopods formed a major part of the benthic macrofauna throughout Silurian times (Llandovery to Pridoli). The orders Strophomenida and Orthotetida are conspicuous components of the brachiopod fauna, and thus the genera and species of the superfamilies Plec− tambonitoidea, Strophomenoidea, and Chilidiopsoidea, which occur in the Silurian of Baltica are reviewed and reidentified in turn, and their individual distributions are assessed within the numerous boreholes of the East Baltic, particularly Lithua− nia, and attributed to benthic assemblages. The commonest plectambonitoids are Eoplectodonta(Eoplectodonta)(6spe− cies), Leangella (2 species), and Jonesea (2 species); rarer forms include Aegiria and Eoplectodonta (Ygerodiscus), for which the new species E. (Y.) bella is erected from the Lithuanian Wenlock. Eight strophomenoid families occur; the rare Leptaenoideidae only in Gotland (Leptaenoidea, Liljevallia). Strophomenidae are represented by Katastrophomena (4 spe− cies), and Pentlandina (2 species); Bellimurina (Cyphomenoidea) is only from Oslo and Gotland. Rafinesquinidae include widespread Leptaena (at least 11 species) and Lepidoleptaena (2 species) with Scamnomena and Crassitestella known only from Gotland and Oslo. In the Amphistrophiidae Amphistrophia is widespread, and Eoamphistrophia, Eocymostrophia, and Mesodouvillina are rare. In the Leptostrophiidae Mesoleptostrophia, Brachyprion,andProtomegastrophia are com− mon, but Eomegastrophia, Eostropheodonta, Erinostrophia,andPalaeoleptostrophia are only recorded from the west in the Baltica Silurian.
    [Show full text]
  • Introduction to the Trilobites: Morphology, Ecology, Macroevolution and More by Michelle M
    Introduction to the Trilobites: Morphology, Ecology, Macroevolution and More By Michelle M. Casey1, Perry Kennard2, and Bruce S. Lieberman1, 3 1Biodiversity Institute, University of Kansas, Lawrence, KS, 66045, 2Earth Science Teacher, Southwest Middle School, USD497, and 3Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045 Middle level laboratory exercise for Earth or General Science; supported provided by National Science Foundation (NSF) grants DEB-1256993 and EF-1206757. Learning Goals and Pedagogy This lab is designed for middle level General Science or Earth Science classes. The learning goals for this lab are the following: 1) to familiarize students with the anatomy and terminology relating to trilobites; 2) to give students experience identifying morphologic structures on real fossil specimens 3) to highlight major events or trends in the evolutionary history and ecology of the Trilobita; and 4) to expose students to the study of macroevolution in the fossil record using trilobites as a case study. Introduction to the Trilobites The Trilobites are an extinct subphylum of the Arthropoda (the most diverse phylum on earth with nearly a million species described). Arthropoda also contains all fossil and living crustaceans, spiders, and insects as well as several other extinct groups. The trilobites were an extremely important and diverse type of marine invertebrates that lived during the Paleozoic Era. They only lived in the oceans but occurred in all types of marine environments, and ranged in size from less than a centimeter to almost a meter across. They were once one of the most successful of all animal groups and in certain fossil deposits, especially in the Cambrian, Ordovician, and Devonian periods, they are extremely abundant.
    [Show full text]
  • The Classic Upper Ordovician Stratigraphy and Paleontology of the Eastern Cincinnati Arch
    International Geoscience Programme Project 653 Third Annual Meeting - Athens, Ohio, USA Field Trip Guidebook THE CLASSIC UPPER ORDOVICIAN STRATIGRAPHY AND PALEONTOLOGY OF THE EASTERN CINCINNATI ARCH Carlton E. Brett – Kyle R. Hartshorn – Allison L. Young – Cameron E. Schwalbach – Alycia L. Stigall International Geoscience Programme (IGCP) Project 653 Third Annual Meeting - 2018 - Athens, Ohio, USA Field Trip Guidebook THE CLASSIC UPPER ORDOVICIAN STRATIGRAPHY AND PALEONTOLOGY OF THE EASTERN CINCINNATI ARCH Carlton E. Brett Department of Geology, University of Cincinnati, 2624 Clifton Avenue, Cincinnati, Ohio 45221, USA ([email protected]) Kyle R. Hartshorn Dry Dredgers, 6473 Jayfield Drive, Hamilton, Ohio 45011, USA ([email protected]) Allison L. Young Department of Geology, University of Cincinnati, 2624 Clifton Avenue, Cincinnati, Ohio 45221, USA ([email protected]) Cameron E. Schwalbach 1099 Clough Pike, Batavia, OH 45103, USA ([email protected]) Alycia L. Stigall Department of Geological Sciences and OHIO Center for Ecology and Evolutionary Studies, Ohio University, 316 Clippinger Lab, Athens, Ohio 45701, USA ([email protected]) ACKNOWLEDGMENTS We extend our thanks to the many colleagues and students who have aided us in our field work, discussions, and publications, including Chris Aucoin, Ben Dattilo, Brad Deline, Rebecca Freeman, Steve Holland, T.J. Malgieri, Pat McLaughlin, Charles Mitchell, Tim Paton, Alex Ries, Tom Schramm, and James Thomka. No less gratitude goes to the many local collectors, amateurs in name only: Jack Kallmeyer, Tom Bantel, Don Bissett, Dan Cooper, Stephen Felton, Ron Fine, Rich Fuchs, Bill Heimbrock, Jerry Rush, and dozens of other Dry Dredgers. We are also grateful to David Meyer and Arnie Miller for insightful discussions of the Cincinnatian, and to Richard A.
    [Show full text]
  • The Larval Stages of Trilobites
    THE LARVAL STAGES OF TRILOBITES. CHARLES E. BEECHER, New Haven, Conn. [From The American Geologist, Vol. XVI, September, 1895.] 166 The American Geologist. September, 1895 THE LARVAL STAGES OF TRILOBITES. By CHARLES E. BEECHEE, New Haven, Conn. (Plates VIII-X.) CONTENTS. PAGE I. Introduction 166 II. The protaspis 167 III. Review of larval stages of trilobites 170 IV. Analysis of variations in trilobite larvae 177 V. Antiquity of the trilobites 181 "VI. Restoration of the protaspis 182 "VII. The crustacean nauplius 186 VIII. Summary 190 IX. References 191 X Explanation of plates 193 I. INTRODUCTION. It is now generally known that the youngest stages of trilobites found as fossils are minute ovate or discoid bodies, not more than one millimetre in length, in which the head por­ tion greatly predominates. Altogether they present very little likeness to the adult form, to which, however, they are trace­ able through a longer or shorter series of modifications. Since Barrande2 first demonstrated the metamorphoses of trilobites, in 1849, similar observations have been made upon a number of different genera by Ford,22 Walcott,34':*>':t6 Mat­ thew,28- 27' 28 Salter,32 Callaway,11' and the writer.4.5-7 The general facts in the ontogeny have thus become well estab­ lished and the main features of the larval form are fairly well understood. Before the recognition of the progressive transformation undergone by trilobites in their development, it was the cus­ tom to apply a name to each variation in the number of tho­ racic segments and in other features of the test.
    [Show full text]
  • Phylogenetic Analysis of the Brachiopod Genus Leptaena Stephanie M
    Family tree of a mass extinction survivor: Phylogenetic analysis of the brachiopod genus Leptaena Stephanie M. Plaza-Torres1, Simon A.F. Darroch2, Peter Wagner2 1University of Puerto Rico, Mayagüez Campus 2Department of Paleobiology, National Museum of Natural History, Smithsonian Institution Results Introduction Discussion Brachiopods are sessile, benthic invertebrates that occupy a wide range of water The weighted parsimony analysis of the species of Leptaena (Fig. 3) reconstructs two depths and are some of the most abundant organisms in the fossil record. Their abundance of the oldest Leptaena species (L. ventricosa [17] and L. infrunita [7]) as the most derived and diversity were their highest during the Paleozoic, having originated back in the species in the tree. Given the general improbability of these relationships, this likely reflects Cambrian, but there are still species that exist today[1]. Of all brachiopod genera, this study late members of a clade including L. delicata (4) through L. cooperi (3) converging upon focuses on Leptaena, a long ranging genus that extends from the Middle Ordovician through those taxa. There is good support for another clade including L. quadrata (11) through L. the Lower Devonian[3]. Leptaena is taxonomically diverse (it has over 50 named species)[3] gibbosa (6). This scenario is supported by very high early disparity (the typical anatomical and spans over two (the end-Ordovician and late-Devonian) of the ‘Big Five’ mass extinction difference among species; Fig. 9), which in turn suggests high early rates of change for events – making it a remarkable serial survivor of global biotic catastrophes. Moreover, Leptaena species.
    [Show full text]
  • The Earliest Phyllolepid (Placodermi, Arthrodira) from the Late Lochkovian (Early Devonian) of Yunnan (South China)
    Geol. Mag. 145 (2), 2008, pp. 257–278. c 2007 Cambridge University Press 257 doi:10.1017/S0016756807004207 First published online 30 November 2007 Printed in the United Kingdom The earliest phyllolepid (Placodermi, Arthrodira) from the Late Lochkovian (Early Devonian) of Yunnan (South China) V. DUPRET∗ &M.ZHU Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, P.O. Box 643, Xizhimenwai Dajie 142, Beijing 100044, People’s Republic of China (Received 1 November 2006; accepted 26 June 2007) Abstract – Gavinaspis convergens, a new genus and species of the Phyllolepida (Placodermi: Arthrodira), is described on the basis of skull remains from the Late Lochkovian (Xitun Formation, Early Devonian) of Qujing (Yunnan, South China). This new form displays a mosaic of characters of basal actinolepidoid arthrodires and more derived phyllolepids. A new hypothesis is proposed concerning the origin of the unpaired centronuchal plate of the Phyllolepida by a fusion of the paired central plates into one single dermal element and the loss of the nuchal plate. A phylogenetic analysis suggests the position of Gavinaspis gen. nov. as the sister group of the Phyllolepididae, in a distinct new family (Gavinaspididae fam. nov.). This new form suggests a possible Chinese origin for the Phyllolepida or that the common ancestor to Phyllolepida lived in an area including both South China and Gondwana, and in any case corroborates the palaeogeographic proximity between Australia and South China during the Devonian Period. Keywords: Devonian, China, Placodermi, phyllolepids, biostratigraphy, palaeobiogeography. 1. Introduction 1934). Subsequently, they were considered as either sharing an immediate common ancestor with the The Phyllolepida are a peculiar group of the Arthrodira Arthrodira (Denison, 1978), belonging to the Actin- (Placodermi), widespread in the Givetian–Famennian olepidoidei (Long, 1984), or being of indetermined of Gondwana (Australia, Antarctica, Turkey, South position within the Arthrodira (Goujet & Young,1995).
    [Show full text]
  • A Solution to Darwin's Dilemma: Differential Taphonomy of Ediacaran and Palaeozoic Non-Mineralised Discoidal Fossils
    Provided by the author(s) and NUI Galway in accordance with publisher policies. Please cite the published version when available. Title A Solution to Darwin's Dilemma: Differential Taphonomy of Ediacaran and Palaeozoic Non-Mineralised Discoidal Fossils Author(s) MacGabhann, Breandán Anraoi Publication Date 2012-08-29 Item record http://hdl.handle.net/10379/3406 Downloaded 2021-09-26T20:57:04Z Some rights reserved. For more information, please see the item record link above. A Solution to Darwin’s Dilemma: Differential taphonomy of Palaeozoic and Ediacaran non- mineralised discoidal fossils Volume 1 of 2 Breandán Anraoi MacGabhann Supervisor: Dr. John Murray Earth and Ocean Sciences, School of Natural Sciences, NUI Galway August 2012 Differential taphonomy of Palaeozoic and Ediacaran non-mineralised fossils Table of Contents List of Figures ........................................................................................................... ix List of Tables ........................................................................................................... xxi Taxonomic Statement ........................................................................................... xxiii Acknowledgements ................................................................................................ xxv Abstract ................................................................................................................. xxix 1. Darwin’s Dilemma ...............................................................................................
    [Show full text]