Articulo Agnostida (Trilobita)
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A New Middle Cambrian Trilobite with a Specialized Cephalon from Shandong Province, North China
Editors' choice A new middle Cambrian trilobite with a specialized cephalon from Shandong Province, North China ZHIXIN SUN, HAN ZENG, and FANGCHEN ZHAO Sun, Z., Zeng, H., and Zhao, F. 2020. A new middle Cambrian trilobite with a specialized cephalon from Shandong Province, North China. Acta Palaeontologica Polonica 65 (4): 709–718. Trilobites achieved their maximum generic diversity in the Cambrian, but the peak of morphological disparity of their cranidia occurred in the Middle to Late Ordovician. Early to middle Cambrian trilobites with a specialized cephalon are rare, especially among the ptychoparioids, a group of libristomates featuring the so-called “generalized” bauplan. Here we describe an unusual ptychopariid trilobite Phantaspis auritus gen. et sp. nov. from the middle Cambrian (Miaolingian, Wuliuan) Mantou Formation in the Shandong Province, North China. This new taxon is characterized by a cephalon with an extended anterior area of double-lobate shape resembling a pair of rabbit ears in later ontogenetic stages; a unique type of cephalic specialization that has not been reported from other trilobites. Such a peculiar cephalon as in Phantaspis provides new insights into the variations of cephalic morphology in middle Cambrian trilobites, and may represent a heuristic example of ecological specialization to predation or an improved discoidal enrollment. Key words: Trilobita, Ptychopariida, ontogeny, specialization, Miaolingian, Paleozoic, Longgang, Asia. Zhixin Sun [[email protected]], Han Zeng [[email protected]], and Fangchen Zhao [[email protected]] (cor responding author), State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palae ontology and Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China. -
Available Generic Names for Trilobites
AVAILABLE GENERIC NAMES FOR TRILOBITES P.A. JELL AND J.M. ADRAIN Jell, P.A. & Adrain, J.M. 30 8 2002: Available generic names for trilobites. Memoirs of the Queensland Museum 48(2): 331-553. Brisbane. ISSN0079-8835. Aconsolidated list of available generic names introduced since the beginning of the binomial nomenclature system for trilobites is presented for the first time. Each entry is accompanied by the author and date of availability, by the name of the type species, by a lithostratigraphic or biostratigraphic and geographic reference for the type species, by a family assignment and by an age indication of the type species at the Period level (e.g. MCAM, LDEV). A second listing of these names is taxonomically arranged in families with the families listed alphabetically, higher level classification being outside the scope of this work. We also provide a list of names that have apparently been applied to trilobites but which remain nomina nuda within the ICZN definition. Peter A. Jell, Queensland Museum, PO Box 3300, South Brisbane, Queensland 4101, Australia; Jonathan M. Adrain, Department of Geoscience, 121 Trowbridge Hall, Univ- ersity of Iowa, Iowa City, Iowa 52242, USA; 1 August 2002. p Trilobites, generic names, checklist. Trilobite fossils attracted the attention of could find. This list was copied on an early spirit humans in different parts of the world from the stencil machine to some 20 or more trilobite very beginning, probably even prehistoric times. workers around the world, principally those who In the 1700s various European natural historians would author the 1959 Treatise edition. Weller began systematic study of living and fossil also drew on this compilation for his Presidential organisms including trilobites. -
Malformed Agnostids from the Middle Cambrian Jince Formation of the Pøíbram-Jince Basin, Czech Republic
Malformed agnostids from the Middle Cambrian Jince Formation of the Pøíbram-Jince Basin, Czech Republic OLDØICH FATKA, MICHAL SZABAD & PETR BUDIL Two agnostids from Cambrian of the Barrandian area bear different types of skeletal malformations. The tiny pathologi- cal exoskeleton of Hypagnostus parvifrons (Linnarsson, 1869) has asymmetrically developed pygidial axis, while the posterior pygidial rim in the larger Phalagnostus prantli Šnajdr, 1957 has an irregular outline. • Key words: agnostids, Middle Cambrian, Jince Formation, Příbram-Jince Basin, Barrandian area, Czech Republic. FATKA, O., SZABAD,M.&BUDIL, P. 2009. Malformed agnostids from the Middle Cambrian Jince Formation of the Příbram-Jince Basin, Czech Republic. Bulletin of Geosciences 84(1), 121–126 (2 figures). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received November 11, 2008; accepted in revised form January 9, 2009; published online January 23, 2009; issued March 31, 2009. Oldřich Fatka, Department of Geology and Palaeontology, Faculty of Science, Charles University, Albertov 6, Praha 2, CZ -128 43, Czech Republic; [email protected] • Michal Szabad, Obránců míru 75, 261 02 Příbram VII, Czech Re- public • Petr Budil, Czech Geological Survey, Klárov 3, Praha 1, CZ -118 21, Czech Republic; [email protected] Numerous examples of exoskeletal abnormalities have discussed by Babcock and Peng (2001). Öpik (1967) de- been described in various polymerid trilobites (e.g., Owen scribed and figured one pathological pygidium of Glyp- 1985, Babcock 1993, Whittington 1997), including para- tagnostus stolidotus Öpik, 1961 with hypertrophic devel- doxidid trilobites from the Cambrian Příbram-Jince Basin opment of the left side of the pygidium. of the Barrandian area (Šnajdr 1978). -
1416 Esteve.Vp
Enrolled agnostids from Cambrian of Spain provide new insights about the mode of life in these forms JORGE ESTEVE & SAMUEL ZAMORA Enrolled agnostids have been known since the beginning of the nineteenth century but assemblages with high number of enrolled specimens are rare. There are different hypotheses about the life habits of this arthropod group and why they en- rolled. These include: a planktic or epiplanktic habit, with the rolled-up posture resulting from clapping cephalon and pygidium together, ectoparasitic habit or a sessile lifestyle, either attached to seaweeds or on the sea floor. Herein we de- scribe two new assemblages from the middle Cambrian of Purujosa (Iberian Chains, North Spain) where agnostids are minor components of the fossil assemblages but occasionally appear enrolled. The taphonomic and sedimentological data suggest that these agnostids were suddenly buried and rolled up as a response to adverse palaeoenvironmental con- ditions. Their presence with typical benthic components supports a benthic mode of life for at least some species of agnostids. • Key words: middle Cambrian, Gondwana, arthropods, behavior, Spain. ESTEVE,J.&ZAMORA, S. 2014. Enrolled agnostids from Cambrian of Spain provide new insights about the mode of life in these forms. Bulletin of Geosciences 89(2), 283–291 (7 figures). Czech Geological Survey, Prague, ISSN 1214-1119. Manuscript received February 5, 2013; accepted in revised form August 6, 2013; published online March 11, 2014; is- sued May 19, 2014. Jorge Esteve, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, No. 39 East Beijing Road, Nanjing 210008, China and University of West Bohemia, Center of Biology, Geosciences and Environment, Klatovská 51, 306 14 Pilsen, Czech Republic; [email protected] • Samuel Zamora, Department of Paleobiology, National Mu- seum of Natural History, Smithsonian Institution, Washington DC, 20013-7012, USA Agnostids were lower Paleozoic (Cambrian–Ordovician) 2011). -
001-012 Primeras Páginas
PUBLICACIONES DEL INSTITUTO GEOLÓGICO Y MINERO DE ESPAÑA Serie: CUADERNOS DEL MUSEO GEOMINERO. Nº 9 ADVANCES IN TRILOBITE RESEARCH ADVANCES IN TRILOBITE RESEARCH IN ADVANCES ADVANCES IN TRILOBITE RESEARCH IN ADVANCES planeta tierra Editors: I. Rábano, R. Gozalo and Ciencias de la Tierra para la Sociedad D. García-Bellido 9 788478 407590 MINISTERIO MINISTERIO DE CIENCIA DE CIENCIA E INNOVACIÓN E INNOVACIÓN ADVANCES IN TRILOBITE RESEARCH Editors: I. Rábano, R. Gozalo and D. García-Bellido Instituto Geológico y Minero de España Madrid, 2008 Serie: CUADERNOS DEL MUSEO GEOMINERO, Nº 9 INTERNATIONAL TRILOBITE CONFERENCE (4. 2008. Toledo) Advances in trilobite research: Fourth International Trilobite Conference, Toledo, June,16-24, 2008 / I. Rábano, R. Gozalo and D. García-Bellido, eds.- Madrid: Instituto Geológico y Minero de España, 2008. 448 pgs; ils; 24 cm .- (Cuadernos del Museo Geominero; 9) ISBN 978-84-7840-759-0 1. Fauna trilobites. 2. Congreso. I. Instituto Geológico y Minero de España, ed. II. Rábano,I., ed. III Gozalo, R., ed. IV. García-Bellido, D., ed. 562 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system now known or to be invented, without permission in writing from the publisher. References to this volume: It is suggested that either of the following alternatives should be used for future bibliographic references to the whole or part of this volume: Rábano, I., Gozalo, R. and García-Bellido, D. (eds.) 2008. Advances in trilobite research. Cuadernos del Museo Geominero, 9. -
Biodiversity Patterns of Early–Middle Ordovician Marine Microphytoplankton in South China
Palaeogeography, Palaeoclimatology, Palaeoecology 299 (2011) 318–334 Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo Biodiversity patterns of Early–Middle Ordovician marine microphytoplankton in South China Kui Yan a,b,c,⁎, Thomas Servais c, Jun Li a,b, Rongchang Wu a, Peng Tang a,b a Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39, East Beijing Road, 210008 Nanjing, China b State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing 210008, China c FRE 3298 du CNRS, Géosystèmes, Université de Lille1, SN5, USTL, F-59655 Villeneuve d'Ascq, France article info abstract Article history: Based on new materials from six sections and all available literature data, new diversity curves are presented Received 22 June 2010 for the phytoplankton (acritarchs) from South China, covering the Early–Middle Ordovician interval, when Received in revised form 18 October 2010 the Great Ordovician Biodiversification Event took place. The total diversity curve and the origination data Accepted 9 November 2010 imply that a major radiation of the phytoplankton occurred during the analysed interval. A peak of the total Available online 13 November 2010 acritarch diversity curve appears in the A. suecicus graptolite biozone. The diversity changes vary in the different parts of the investigated area, most probably depending on the position of the analysed sections on Keywords: the carbonate shelf or the slope, reflecting diversity differences due to the position on an inshore–offshore Acritarchs Early–Middle Ordovician transect. South China The Early–Middle Ordovician diversity pattern of the phytoplankton is compared with those of several marine Biodiversity invertebrate groups. -
Fossils from South China Redefine the Ancestral Euarthropod Body Plan Cédric Aria1 , Fangchen Zhao1, Han Zeng1, Jin Guo2 and Maoyan Zhu1,3*
Aria et al. BMC Evolutionary Biology (2020) 20:4 https://doi.org/10.1186/s12862-019-1560-7 RESEARCH ARTICLE Open Access Fossils from South China redefine the ancestral euarthropod body plan Cédric Aria1 , Fangchen Zhao1, Han Zeng1, Jin Guo2 and Maoyan Zhu1,3* Abstract Background: Early Cambrian Lagerstätten from China have greatly enriched our perspective on the early evolution of animals, particularly arthropods. However, recent studies have shown that many of these early fossil arthropods were more derived than previously thought, casting uncertainty on the ancestral euarthropod body plan. In addition, evidence from fossilized neural tissues conflicts with external morphology, in particular regarding the homology of the frontalmost appendage. Results: Here we redescribe the multisegmented megacheirans Fortiforceps and Jianfengia and describe Sklerolibyon maomima gen. et sp. nov., which we place in Jianfengiidae, fam. nov. (in Megacheira, emended). We find that jianfengiids show high morphological diversity among megacheirans, both in trunk ornamentation and head anatomy, which encompasses from 2 to 4 post-frontal appendage pairs. These taxa are also characterized by elongate podomeres likely forming seven-segmented endopods, which were misinterpreted in their original descriptions. Plesiomorphic traits also clarify their connection with more ancestral taxa. The structure and position of the “great appendages” relative to likely sensory antero-medial protrusions, as well as the presence of optic peduncles and sclerites, point to an overall -
Gutturu Pala (Iglesiente, Sluf Sardinia, Itdy) Cambrian
Bollenino delk Societh Pahontohgica Italiana 43(3),2004 rssN0375-7633 383-40r 3 pls. Modena, Dicembre 2004 Cambrian microfauna and palaeoecologyof the Campo Pisano Formation at Gutturu Pala (Iglesiente, SlUf Sardinia, Itdy) Olaf EI-Icru Gian Luigi Ptllom TU BereakademieFreibere Universit)r deeli studi di Casliari Geologiscf,esInstitut, Freibirg Diparti-ento"Scienze della Terra I(EY lrfORDS - Microfossils,Palaeoecologl, Campo Pisano Formation, Cambrian, Sardir ABSTMCT - The microfossilcontent of nodukr limestonesof the late Early to Middle Gutturu Pala sectionofsouth*ritrrn Sardinia is describedand discusid with ,ttpttito pakeoeco tigations, the uerticaliuccasion of the sedimentaryeuolution andfossil distibuiion is intqrpretet to at hast deep-subt;dil con, tfaot conditionsa! tle bgginyini of yhe Campo.ri:f"y Formatioln tics, an interim shalhwing during that processu likely. A dramatic facies,toTntt*eit wit6 the onsetof tbe Cam\o PisanoFormation indicat€slt strt by tectonicinstahitity oftht pktfor*, Accompaniel.by modeiaterektiue sea-leuelrise and pakeol frott of the time, thi pirsistintiof onb onepaktott6hgical assembkgeindicates a more5r hssii for' mo,stof the,CarnpoPisano time. Aming the taxa representedin the highly fossiliferoussediments, trilobites, echinoderms,b elementsarZ chancelhrilids,hyolithids, ptk7leltih, hiolithelminthids, and bradoriid arthropods. is pubtished herefor the fii, tirye. The foaqwing bradoriid and trih_Qitesryciel are newly t Condylopyge aniiqua n.-sp.,and - dzscribedin optn nomenclature- Clavigellusi n.sP. -
The Evolution of Trilobite Body Patterning
ANRV309-EA35-14 ARI 20 March 2007 15:54 The Evolution of Trilobite Body Patterning Nigel C. Hughes Department of Earth Sciences, University of California, Riverside, California 92521; email: [email protected] Annu. Rev. Earth Planet. Sci. 2007. 35:401–34 Key Words First published online as a Review in Advance on Trilobita, trilobitomorph, segmentation, Cambrian, Ordovician, January 29, 2007 diversification, body plan The Annual Review of Earth and Planetary Sciences is online at earth.annualreviews.org Abstract This article’s doi: The good fossil record of trilobite exoskeletal anatomy and on- 10.1146/annurev.earth.35.031306.140258 togeny, coupled with information on their nonbiomineralized tis- Copyright c 2007 by Annual Reviews. sues, permits analysis of how the trilobite body was organized and All rights reserved developed, and the various evolutionary modifications of such pat- 0084-6597/07/0530-0401$20.00 terning within the group. In several respects trilobite development and form appears comparable with that which may have charac- terized the ancestor of most or all euarthropods, giving studies of trilobite body organization special relevance in the light of recent advances in the understanding of arthropod evolution and devel- opment. The Cambrian diversification of trilobites displayed mod- Annu. Rev. Earth Planet. Sci. 2007.35:401-434. Downloaded from arjournals.annualreviews.org ifications in the patterning of the trunk region comparable with by UNIVERSITY OF CALIFORNIA - RIVERSIDE LIBRARY on 05/02/07. For personal use only. those seen among the closest relatives of Trilobita. In contrast, the Ordovician diversification of trilobites, although contributing greatly to the overall diversity within the clade, did so within a nar- rower range of trunk conditions. -
Soft Anatomy of the Early Cambrian Arthropod Isoxys Curvirostratus from the Chengjiang Biota of South China with a Discussion on the Origination of Great Appendages
Soft anatomy of the Early Cambrian arthropod Isoxys curvirostratus from the Chengjiang biota of South China with a discussion on the origination of great appendages DONG−JING FU, XING−LIANG ZHANG, and DE−GAN SHU Fu, D.−J., Zhang, X.−L., and Shu, D.−G. 2011. Soft anatomy of the Early Cambrian arthropod Isoxys curvirostratus from the Chengjiang biota of South China with a discussion on the origination of great appendages. Acta Palaeontologica Polonica 56 (4): 843–852. An updated reconstruction of the body plan, functional morphology and lifestyle of the arthropod Isoxys curvirostratus is proposed, based on new fossil specimens with preserved soft anatomy found in several localities of the Lower Cambrian Chengjiang Lagerstätte. The animal was 2–4 cm long and mostly encased in a single carapace which is folded dorsally without an articulated hinge. The attachment of the body to the exoskeleton was probably cephalic and apparently lacked any well−developed adductor muscle system. Large stalked eyes with the eye sphere consisting of two layers (as corneal and rhabdomeric structures) protrude beyond the anterior margin of the carapace. This feature, together with a pair of frontal appendages with five podomeres that each bear a stout spiny outgrowth, suggests it was raptorial. The following 14 pairs of limbs are biramous and uniform in shape. The slim endopod is composed of more than 7 podomeres without terminal claw and the paddle shaped exopod is fringed with at least 17 imbricated gill lamellae along its posterior margin. The design of exopod in association with the inner vascular (respiratory) surface of the carapace indicates I. -
Ptychopariid Trilobites in the Middle Cambrian of Central Bohemia (Taxonomy, Biostratigraphy, Synecology)
Ptychopariid trilobites in the Middle Cambrian of Central Bohemia (taxonomy, biostratigraphy, synecology) VRATISLAV KORDULE A revision of ptychopariid trilobites from the Middle Cambrian of central Bohemia is presented. With a few exceptions, they were previously referred only to Ptychoparia striata. Three genera are recently distinguished: Ptychoparia Hawle & Corda, 1847, Ptychoparioides Růžička, 1940, and Mikaparia gen. nov. Seven species are described: three are revised, four are new, and two is left in open nomenclature; their stratigraphical ranges and significance are discussed. A new stratigraphical subdivision of the Middle Cambrian of the Skryje-Týřovice area is suggested, including three assemblage zones and three barren zones. Four substrate and bathymetrically controlled trilobite associations are recognized in the Skryje-Týřovice area. • Key words: Bohemia, Middle Cambrian, trilobites, new taxa, biostratigraphy. KORDULE, V. 2006. Ptychopariid trilobites in the Middle Cambrian of Central Bohemia (taxonomy, biostratigraphy, synecology). Bulletin of Geosciences 81(4), 277–304 (13 figures). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript received February 17, 2005; accepted in revised form December 4, 2006; issued December 31, 2006. Vratislav Kordule, Dlouhá 104, 261 01 Příbram III, Czech Republic; [email protected] Representatives of the genera Ptychoparia Hawle & Corda to study the materials in Vokáč’s private collection, the 1847, Ptychoparioides Růžička, 1940, and Mikaparia gen. specimens described and figured by Vokáč (1997) can be nov. are significant components of the trilobite fauna of identified, and their taxonomic position is revised. the Middle Cambrian marine deposits in the Jince and Following the previous stratigraphical models (their Skryje-Týřovice areas. Specimens referred to these taxa summary is given in Havlíček 1998 and Fatka et al. -
The Late Ordovician Mass Extinction
P1: FXY/GBP P2: aaa February 24, 2001 19:23 Annual Reviews AR125-12 Annu. Rev. Earth Planet. Sci. 2001. 29:331–64 Copyright c 2001 by Annual Reviews. All rights reserved THE LATE ORDOVICIAN MASS EXTINCTION Peter M Sheehan Department of Geology, Milwaukee Public Museum, Milwaukee, Wisconsin 53233; e-mail: [email protected] Key Words extinction event, Silurian, glaciation, evolutionary recovery, ecologic evolutionary unit ■ Abstract Near the end of the Late Ordovician, in the first of five mass extinctions in the Phanerozoic, about 85% of marine species died. The cause was a brief glacial interval that produced two pulses of extinction. The first pulse was at the beginning of the glaciation, when sea-level decline drained epicontinental seaways, produced a harsh climate in low and mid-latitudes, and initiated active, deep-oceanic currents that aerated the deep oceans and brought nutrients and possibly toxic material up from oceanic depths. Following that initial pulse of extinction, surviving faunas adapted to the new ecologic setting. The glaciation ended suddenly, and as sea level rose, the climate moderated, and oceanic circulation stagnated, another pulse of extinction occurred. The second extinction marked the end of a long interval of ecologic stasis (an Ecologic-Evolutionary Unit). Recovery from the event took several million years, but the resulting fauna had ecologic patterns similar to the fauna that had become extinct. Other extinction events that eliminated similar or even smaller percentages of species had greater long-term ecologic effects. INTRODUCTION The Late Ordovician extinction was the first of five great extinction events of the by Universidad Nacional Autonoma de Mexico on 03/15/13.