APS Bulletin, September 2014, Volume 29, Number 3
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Integrative and Comparative Biology Integrative and Comparative Biology, Volume 58, Number 4, Pp
Integrative and Comparative Biology Integrative and Comparative Biology, volume 58, number 4, pp. 605–622 doi:10.1093/icb/icy088 Society for Integrative and Comparative Biology SYMPOSIUM INTRODUCTION The Temporal and Environmental Context of Early Animal Evolution: Considering All the Ingredients of an “Explosion” Downloaded from https://academic.oup.com/icb/article-abstract/58/4/605/5056706 by Stanford Medical Center user on 15 October 2018 Erik A. Sperling1 and Richard G. Stockey Department of Geological Sciences, Stanford University, 450 Serra Mall, Building 320, Stanford, CA 94305, USA From the symposium “From Small and Squishy to Big and Armored: Genomic, Ecological and Paleontological Insights into the Early Evolution of Animals” presented at the annual meeting of the Society for Integrative and Comparative Biology, January 3–7, 2018 at San Francisco, California. 1E-mail: [email protected] Synopsis Animals originated and evolved during a unique time in Earth history—the Neoproterozoic Era. This paper aims to discuss (1) when landmark events in early animal evolution occurred, and (2) the environmental context of these evolutionary milestones, and how such factors may have affected ecosystems and body plans. With respect to timing, molecular clock studies—utilizing a diversity of methodologies—agree that animal multicellularity had arisen by 800 million years ago (Ma) (Tonian period), the bilaterian body plan by 650 Ma (Cryogenian), and divergences between sister phyla occurred 560–540 Ma (late Ediacaran). Most purported Tonian and Cryogenian animal body fossils are unlikely to be correctly identified, but independent support for the presence of pre-Ediacaran animals is recorded by organic geochemical biomarkers produced by demosponges. -
(2014). Haootia Quadriformis N. Gen., N. Sp., Interpreted As a Muscular Cnidarian Impression from the Late Ediacaran Period (Approx
Liu, A. G. S., Matthews, J., Menon, L. R., McIlroy, D., & Brasier, M. D. (2014). Haootia quadriformis n. gen., n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran period (approx. 560 Ma). Proceedings of the Royal Society B: Biological Sciences, 281(1793), [20141202]. https://doi.org/10.1098/rspb.2014.1202 Peer reviewed version License (if available): Unspecified Link to published version (if available): 10.1098/rspb.2014.1202 Link to publication record in Explore Bristol Research PDF-document University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ 1 Title: Haootia quadriformis n. gen., n. sp., interpreted as a 2 muscular cnidarian impression from the late Ediacaran Period 3 (~560 Ma) 4 Authors: Alexander G. Liu1, *, Jack J. Matthews2, Latha R. Menon2, Duncan McIlroy3 and 5 Martin D. Brasier2, 3 6 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 7 3EQ, U.K. 8 2Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, 9 U.K. 10 3Department of Earth Sciences, Memorial University of Newfoundland, 300 Prince Philip 11 Drive, St. John’s, NL, A1B 3X5, Canada 12 *Corresponding Author. Email: [email protected] 13 14 Key words: Ediacaran, metazoan, Newfoundland, Cnidaria, muscle 15 16 Abstract 17 Muscle tissue is a fundamentally eumetazoan attribute. The oldest evidence for fossilized 18 muscular tissue before the early Cambrian has hitherto remained moot, being reliant upon 19 indirect evidence in the form of late Ediacaran ichnofossils. -
Annual Meeting 2014
The Palaeontological Association 58th Annual Meeting 16th–19th December 2014 University of Leeds PROGRAMME abstracts and AGM papers Public transport to the University of Leeds BY TRAIN: FROM TRAIN STATION ON FOOT: Leeds Train Station links regularly to all major UK cities. You The University campus is a 20 minute walk from the train can get from the station to the campus on foot, by taxi or by station. The map below will help you find your way. bus. A taxi ride will take about 10 minutes and it will cost Leave the station through the exit facing the main concourse. approximately £5. Turn left past the bus stops and walk down towards City Square. Keeping City Square on your left, walk straight up FROM TRAIN STATION BY BUS: Park Row. At the top of the road turn right onto The Headrow, We advise you to take bus number 1 which departs from passing The Light shopping centre on your left. After The Light Infirmary Street. The bus runs approximately every 10 minutes turn left onto Woodhouse Lane to continue uphill. Keep going, and the journey takes 10 minutes. passing Morrisons, Leeds Metropolitan and the Dry Dock You should get off the bus just outside the Parkinson Building. boat pub heading for the large white clock tower. This is the (There is also the £1 Leeds City Bus which takes you from the Parkinson building. train station to the lower end of campus but the journey time is much longer). BY COACH: If you arrive by coach you can catch bus numbers 6,28 or 97 to the University (Parkinson Building). -
The Origin of Animals: Can Molecular Clocks and the Fossil Record Be Reconciled?
Prospects & Overviews Review essays The origin of animals: Can molecular clocks and the fossil record be reconciled? John A. Cunningham1)2)Ã, Alexander G. Liu1)†, Stefan Bengtson2) and Philip C. J. Donoghue1) The evolutionary emergence of animals is one of the most Introduction significant episodes in the history of life, but its timing remains poorly constrained. Molecular clocks estimate that The apparent absence of a fossil record prior to the appearance of trilobites in the Cambrian famously troubled Darwin. He animals originated and began diversifying over 100 million wrote in On the origin of species that if his theory of evolution years before the first definitive metazoan fossil evidence in were true “it is indisputable that before the lowest [Cambrian] the Cambrian. However, closer inspection reveals that clock stratum was deposited ... the world swarmed with living estimates and the fossil record are less divergent than is creatures.” Furthermore, he could give “no satisfactory answer” often claimed. Modern clock analyses do not predict the as to why older fossiliferous deposits had not been found [1]. In the intervening century and a half, a record of Precambrian presence of the crown-representatives of most animal phyla fossils has been discovered extending back over three billion in the Neoproterozoic. Furthermore, despite challenges years (popularly summarized in [2]). Nevertheless, “Darwin’s provided by incomplete preservation, a paucity of phylo- dilemma” regarding the origin and early evolution of Metazoa genetically informative characters, and uncertain expecta- arguably persists, because incontrovertible fossil evidence for tions of the anatomy of early animals, a number of animals remains largely, or some might say completely, absent Neoproterozoic fossils can reasonably be interpreted as from Neoproterozoic rocks [3]. -
Evolution, Origins and Diversification of Parasitic Cnidarians
1 Evolution, Origins and Diversification of Parasitic Cnidarians Beth Okamura*, Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom. Email: [email protected] Alexander Gruhl, Department of Symbiosis, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany *Corresponding author 12th August 2020 Keywords Myxozoa, Polypodium, adaptations to parasitism, life‐cycle evolution, cnidarian origins, fossil record, host acquisition, molecular clock analysis, co‐phylogenetic analysis, unknown diversity Abstract Parasitism has evolved in cnidarians on multiple occasions but only one clade – the Myxozoa – has undergone substantial radiation. We briefly review minor parasitic clades that exploit pelagic hosts and then focus on the comparative biology and evolution of the highly speciose Myxozoa and its monotypic sister taxon, Polypodium hydriforme, which collectively form the Endocnidozoa. Cnidarian features that may have facilitated the evolution of endoparasitism are highlighted before considering endocnidozoan origins, life cycle evolution and potential early hosts. We review the fossil evidence and evaluate existing inferences based on molecular clock and co‐phylogenetic analyses. Finally, we consider patterns of adaptation and diversification and stress how poor sampling might preclude adequate understanding of endocnidozoan diversity. 2 1 Introduction Cnidarians are generally regarded as a phylum of predatory free‐living animals that occur as benthic polyps and pelagic medusa in the world’s oceans. They include some of the most iconic residents of marine environments, such as corals, sea anemones and jellyfish. Cnidarians are characterised by relatively simple body‐plans, formed entirely from two tissue layers (the ectoderm and endoderm), and by their stinging cells or nematocytes. -
How Cnidaria Got Its Cnidocysts
tems: ys Op l S e a n A ic c g c o l e s o i s Shostak, Biol syst Open Access 2015, 4:2 B Biological Systems: Open Access DOI: 10.4172/2329-6577.1000139 ISSN: 2329-6577 Review Article Open Access How Cnidaria Got Its Cnidocysts Stanley Shostak* Department of Biological Sciences, University of Pittsburgh, USA *Corresponding author: Stanley Shostak, Department of Biological Sciences, University of Pittsburgh, USA, Tel: 0114129156595, E-mail: [email protected] Received date: May 06, 2015; Accepted date: Aug 03, 2015; Published date: Aug 11, 2015 Copyright: © 2015 Shostak S. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract A complex hypothesis is offered for the origins of cnidarian cnidocysts through symbiogeny. The two-part hypothetical pathway links the origins of tissues through an early amalgamation of amoebic and epithelial cells to and the later introduction of an extrusion apparatus from bacterial parasites. The first part of the hypothesis is based on evidence for morphological, molecular, and developmental similarities of cnidarians and myxozoans indicative of common ancestry. Support is drawn from Ediacaran fossils suggesting that stem-metazoans consisted of symbiogenic pairs of epithelial-like shells enclosing amoeba-like cells. The amoeba-like cells would have evolved into germ cells and cells differentiating as or inducing nerve, muscle, and gland cells. The second part of the hypothesis proposes that cnidocysts evolved in a cnidarian/myxozoan branch of the metazoan tree through the horizontal transfer of bacterial genes encoding an extrusion apparatus to proto-cnidarian amoebic cells and consequently to the Cnidarian germ line. -
Mistaken Point, with Insets Showing Some of the Diverse Ediacaran Macrofossils Present at Mistake Point (Photo: A
Open File NFLD/3320 GEOLOGICAL ASSOCIATION OF CANADA Newfoundland and Labrador Section 2015 FALL FIELD TRIP The Ediacaran fossils of the Avalon Peninsula Alex G. Liu and James Conliffe with contributions from Liam Herringshaw, Jack Matthews, and Duncan McIlroy September 18–20th, 2015 Cover photo: Overview of the fossil bearing bedding planes at Mistaken Point, with insets showing some of the diverse Ediacaran macrofossils present at Mistake Point (photo: A. Liu) GAC Newfoundland and Labrador Section – 2015 Fall Field Trip Ediacaran macrofossils from the Mistaken Point ‘E’ Surface. 2 GAC Newfoundland and Labrador Section – 2015 Fall Field Trip TABLE OF CONTENTS INTRODUCTION AND OVERVIEW 4 ACKNOWLEDGEMENTS 4 SAFETY INFORMATION 5 MISTAKEN POINT ECOLOGICAL RESERVE (MPER) 7 PART 1: BACKGROUND MATERIAL 9 INTRODUCTION 9 Introduction to the Neoproterozoic‒Phanerozoic Transition 9 Stratigraphy, Structural Geology, and Depositional Environment of the Avalon Peninsula 13 EDICARAN PALEONTOLOGY OF THE AVALON PENINSULA 16 Preservation of Ediacaran macrofossils 16 The Avalon Assemblage 18 Current research into the Mistaken Point Ediacaran Fossils 21 PART 2: FIELD TRIP ITINERARY 24 Day One – Harbour Main and Spaniard’s Bay 25 Day Two – Mistaken Point Ecological Reserve 31 Day Three – Mistaken Point Ecological Reserve and Ferryland 46 INVENTORY OF TAXA IN MISTAKEN POINT ECOLOGICAL RESERVE 53 REFERENCES 54 3 GAC Newfoundland and Labrador Section – 2015 Fall Field Trip INTRODUCTION AND OVERVIEW The Mistaken Point Ecological Reserve (Fig. 1) is home to the some of the world’s most impressive Ediacaran fossil assemblages. Large bedding planes covered in thousands of exceptionally preserved specimens can be found in situ throughout a continuous ~2 km succession of sedimentary strata. -
SERIES Ontogeny, Taphonomy, Taxonomy and Morphology, Offering Insights Into the Possible Phylogenetic Positions of Ediacaran Taxa Within the Tree of Life
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by ESC Publications - Cambridge Univesity GEOSCIENCE CANADA Volume 44 2017 63 SERIES ontogeny, taphonomy, taxonomy and morphology, offering insights into the possible phylogenetic positions of Ediacaran taxa within the tree of life. Meanwhile, a thick and continuous geological record enables the fossils to be placed within a well- resolved temporal and paleoenvironmental context spanning an interval of at least 10 million years. This article reviews the history of paleontological research at MPER, and highlights key discoveries that have shaped global thinking on the Edi- acaran macrobiota. RÉSUMÉ Le site du Patrimoine mondial de la Réserve écologique de Mis- taken Point (MPER), sur la côte sud-est de Terre-Neuve, au Canada, est l'une des principales localités fossilifères édiacari- ennes de la planète. Le MPER renferme quelques-uns des plus anciens assemblages connus de macrobiote édicarien à parties Great Canadian Lagerstätten 6. molles, et ses fossiles ont contribué de manière significative à Mistaken Point Ecological Reserve, la recherche paléobiologique édiacarienne depuis leur décou- verte en 1967. La préservation de multiples paléocommu- Southeast Newfoundland nautés benthiques in situ, dont certaines comptant des milliers de spécimens, a permis de faire des recherches en paléoécolo- Alexander G. Liu1 and Jack J. Matthews2, 3 gie, ontogenèse, taphonomie, taxonomie et morphologie de biotes édiacariens, ce qui a permis d’avoir un aperçu de dif- 1Department of Earth Sciences férentes positions phylogénétiques possibles des taxons édi- University of Cambridge acariens dans l'arborescence biologique. Aussi, grâce à une Downing Street, Cambridge, CB2 3EQ, United Kingdom colonne géologique épaisse et continue, on a pu placer ces fos- E-mail: [email protected] siles dans un contexte temporel et paléoenvironnemental bien circonscrit qui s’étend sur un intervalle d'au moins 10 millions 2Department of Earth Sciences d'années. -
'Savannah' Hypothesis for Early Bilaterian Evolution
Biol. Rev. (2017), 92, pp. 446–473. 446 doi: 10.1111/brv.12239 The origin of the animals and a ‘Savannah’ hypothesis for early bilaterian evolution Graham E. Budd1,∗ and Soren¨ Jensen2 1Palaeobiology Programme, Department of Earth Sciences, Uppsala University, Villav¨agen 16, SE 752 40 Uppsala, Sweden 2Area´ de Paleontología, Facultad de Ciencias, Universidad de Extremadura, 06006 Badajoz, Spain ABSTRACT The earliest evolution of the animals remains a taxing biological problem, as all extant clades are highly derived and the fossil record is not usually considered to be helpful. The rise of the bilaterian animals recorded in the fossil record, commonly known as the ‘Cambrian explosion’, is one of the most significant moments in evolutionary history, and was an event that transformed first marine and then terrestrial environments. We review the phylogeny of early animals and other opisthokonts, and the affinities of the earliest large complex fossils, the so-called ‘Ediacaran’ taxa. We conclude, based on a variety of lines of evidence, that their affinities most likely lie in various stem groups to large metazoan groupings; a new grouping, the Apoikozoa, is erected to encompass Metazoa and Choanoflagellata. The earliest reasonable fossil evidence for total-group bilaterians comes from undisputed complex trace fossils that are younger than about 560 Ma, and these diversify greatly as the Ediacaran–Cambrian boundary is crossed a few million years later. It is generally considered that as the bilaterians diversified after this time, their burrowing behaviour destroyed the cyanobacterial mat-dominated substrates that the enigmatic Ediacaran taxa were associated with, the so-called ‘Cambrian substrate revolution’, leading to the loss of almost all Ediacara-aspect diversity in the Cambrian. -
(2014). Haootia Quadriformis N. Gen., N. Sp., Interpreted As a Muscular Cnidarian Impression from the Late Ediacaran Period (Approx
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Explore Bristol Research Liu, A. G. S., Matthews, J., Menon, L. R., McIlroy, D., & Brasier, M. D. (2014). Haootia quadriformis n. gen., n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran period (approx. 560 Ma). Proceedings of the Royal Society B: Biological Sciences, 281(1793), [20141202]. https://doi.org/10.1098/rspb.2014.1202 Peer reviewed version License (if available): Unspecified Link to published version (if available): 10.1098/rspb.2014.1202 Link to publication record in Explore Bristol Research PDF-document University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms 1 Title: Haootia quadriformis n. gen., n. sp., interpreted as a 2 muscular cnidarian impression from the late Ediacaran Period 3 (~560 Ma) 4 Authors: Alexander G. Liu1, *, Jack J. Matthews2, Latha R. Menon2, Duncan McIlroy3 and 5 Martin D. Brasier2, 3 6 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 7 3EQ, U.K. 8 2Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, 9 U.K. 10 3Department of Earth Sciences, Memorial University of Newfoundland, 300 Prince Philip 11 Drive, St. John’s, NL, A1B 3X5, Canada 12 *Corresponding Author. Email: [email protected] 13 14 Key words: Ediacaran, metazoan, Newfoundland, Cnidaria, muscle 15 16 Abstract 17 Muscle tissue is a fundamentally eumetazoan attribute. -
Late Ediacaran Organic Microfossils from Finland
Geological Magazine Late Ediacaran organic microfossils from www.cambridge.org/geo Finland Sebastian Willman and Ben J. Slater Original Article Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, SE-75236, Uppsala, Sweden Cite this article: Willman S and Slater BJ. Late Abstract Ediacaran organic microfossils from Finland. Geological Magazine https://doi.org/10.1017/ Here we present a detailed accounting of organic microfossils from late Ediacaran sediments S0016756821000753 of Finland, from the island of Hailuoto (northwest Finnish coast), and the Saarijärvi meteorite impact structure (~170 km northeast of Hailuoto, mainland Finland). Fossils were Received: 16 March 2021 recovered from fine-grained thermally immature mudstones and siltstones and are preserved Revised: 10 June 2021 Accepted: 24 June 2021 in exquisite detail. The majority of recovered forms are sourced from filamentous prokaryotic and protistan-grade organisms forming interwoven microbial mats. Flattened Nostoc-ball-like Keywords: masses of bundled Siphonophycus filaments are abundant, alongside Rugosoopsis and Ediacaran; Bilateria; microbial mats; acritarchs; Palaeolyngbya of probable cyanobacterial origin. Acritarchs include Chuaria, Leiosphaeridia, impact crater; organic-walled microfossils; Symplassosphaeridium and Synsphaeridium. Significantly, rare spine-shaped sclerites of Baltica bilaterian origin were recovered, providing new evidence for a nascent bilaterian fauna in Author for correspondence: the terminal Ediacaran. These findings offer a direct body-fossil insight into Ediacaran Sebastian Willman, mat-forming microbial communities, and demonstrate that alongside trace fossils, detection Email: [email protected]; of a bilaterian fauna prior to the Cambrian might also be sought among the emerging record Ben Slater, Email: [email protected] of small carbonaceous fossils (SCFs). -
Is Haootia Quadriformis Related to Extant Staurozoa (Cnidaria)? Evidence from the Muscular System Reconsidered
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP) Universidade de São Paulo Biblioteca Digital da Produção Intelectual - BDPI Centro de Biologia Marinha - CEBIMar Artigos e Materiais de Revistas Científicas - CEBIMar 2015-03 Is Haootia quadriformis related to extant Staurozoa (Cnidaria)? Evidence from the muscular system reconsidered http://www.producao.usp.br/handle/BDPI/49560 Downloaded from: Biblioteca Digital da Produção Intelectual - BDPI, Universidade de São Paulo Downloaded from http://rspb.royalsocietypublishing.org/ on December 17, 2015 Is Haootia quadriformis related to extant rspb.royalsocietypublishing.org Staurozoa (Cnidaria)? Evidence from the muscular system reconsidered L. S. Miranda1, A. G. Collins2 and A. C. Marques1,3 Comment 1Instituto de Biocieˆncias, Departamento de Zoologia, Universidade de Sa˜o Paulo, Sa˜o Paulo, Sa˜o Paulo, Brazil 2 Cite this article: Miranda LS, Collins AG, National Systematics Laboratory, National Marine Fisheries Service (NMFS), National Museum of Natural History, Smithsonian Institution, Washington, DC, USA Marques AC. 2015 Is Haootia quadriformis 3Centro de Biologia Marinha, Universidade de Sa˜o Paulo, Sa˜o Sebastia˜o, Sa˜o Paulo, Brazil related to extant Staurozoa (Cnidaria)? Evi- dence from the muscular system reconsidered. Proc. R. Soc. B 282: 20142396. Haootia quadriformis was described from the lower Fermeuse Formation of the http://dx.doi.org/10.1098/rspb.2014.2396 Bonavista Peninsula of Newfoundland (approx. 560 Ma) and its numerous regu- larly aligned impressions were interpreted as evidence of muscular tissue ([1, figs 1a and 3b]). Consequently, this fossil could represent the earliest preservation of metazoan musculature in the geological record.