Development, Anatomy, and Phylogenetic Relationships of Jawless Vertebrates and Tests of Hypotheses About Early Vertebrate Evolution
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The Phylum Vertebrata: a Case for Zoological Recognition Naoki Irie1,2* , Noriyuki Satoh3 and Shigeru Kuratani4
Irie et al. Zoological Letters (2018) 4:32 https://doi.org/10.1186/s40851-018-0114-y REVIEW Open Access The phylum Vertebrata: a case for zoological recognition Naoki Irie1,2* , Noriyuki Satoh3 and Shigeru Kuratani4 Abstract The group Vertebrata is currently placed as a subphylum in the phylum Chordata, together with two other subphyla, Cephalochordata (lancelets) and Urochordata (ascidians). The past three decades, have seen extraordinary advances in zoological taxonomy and the time is now ripe for reassessing whether the subphylum position is truly appropriate for vertebrates, particularly in light of recent advances in molecular phylogeny, comparative genomics, and evolutionary developmental biology. Four lines of current research are discussed here. First, molecular phylogeny has demonstrated that Deuterostomia comprises Ambulacraria (Echinodermata and Hemichordata) and Chordata (Cephalochordata, Urochordata, and Vertebrata), each clade being recognized as a mutually comparable phylum. Second, comparative genomic studies show that vertebrates alone have experienced two rounds of whole-genome duplication, which makes the composition of their gene family unique. Third, comparative gene-expression profiling of vertebrate embryos favors an hourglass pattern of development, the most conserved stage of which is recognized as a phylotypic period characterized by the establishment of a body plan definitively associated with a phylum. This mid-embryonic conservation is supported robustly in vertebrates, but only weakly in chordates. Fourth, certain complex patterns of body plan formation (especially of the head, pharynx, and somites) are recognized throughout the vertebrates, but not in any other animal groups. For these reasons, we suggest that it is more appropriate to recognize vertebrates as an independent phylum, not as a subphylum of the phylum Chordata. -
Alfred Romer – Wikipedia
Alfred Romer – Wikipedia https://de.wikipedia.org/wiki/Alfred_Romer aus Wikipedia, der freien Enzyklopädie Alfred Sherwood Romer (* 28. Dezember 1894 in White Plains, New York; † 5. November 1973) war ein US-amerikanischer Paläontologe. Sein Fachgebiet war die Evolution der Wirbeltiere. Inhaltsverzeichnis 1 Leben 2 Romer-Lücke 3 Auszeichnungen und Ehrungen 4 Schriften 5 Weblinks 6 Einzelnachweise Leben Alfred Sherwood Romer wurde in White Plains, New York geboren, wo er seinen High-School-Abschluss machte. Danach arbeitete er ein Jahr lang als Angestellter bei der Eisenbahn und entschloss sich dann doch für den Besuch eines College. Mit Hilfe eines Stipendiums vom Amherst College konnte er dort Geschichte und deutsche Literatur studieren. Durch häufige Besuche des American Museum of Natural History entdeckte er seine Begeisterung für naturkundliche Fossilien. Bei Ausbruch des Ersten Weltkriegs meldete er sich als Freiwilliger zum Kriegsdienst und wurde sofort in Frankreich eingesetzt. 1919 kam er zurück nach New York und nahm das Studium der Biologie an der Columbia University auf, das er bereits zwei Jahre später mit der Promotion abschloss. Danach war er als wissenschaftliche Hilfskraft an der Bellevue Medical School der New York University beschäftigt und lehrte insbesondere Histologie, Embryologie und Allgemeine Anatomie. 1923 erhielt er einen Ruf von der Universität Chicago, wo er seine spätere Ehefrau Ruth kennenlernte, mit der er drei Kinder hatte. In Chicago fand er Bedingungen vor, die es ihm ermöglichten, sein Hauptinteresse zu intensivieren - die Paläontologie. So entstanden in den Jahren von 1925 bis 1935 37 Fachartikel, die sich mit diesem Thema befassten. 1934 wurde er zum Professor für Biologie an der Harvard University ernannt. -
Illinois Fossils Doc 2005
State of Illinois Illinois Department of Natural Resources Illinois Fossils Illinois Department of Natural Resources he Illinois Fossils activity book from the Illinois Department of Natural Resources’ (IDNR) Division of Education is designed to supplement your curriculum in a vari- ety of ways. The information and activities contained in this publication are targeted toT grades four through eight. The Illinois Fossils resources trunk and lessons can help you T teach about fossils, too. You will find these and other supplemental items through the Web page at https://www2.illinois.gov/dnr/education/Pages/default.aspx. Contact the IDNR Division of Education at 217-524-4126 or [email protected] for more information. Collinson, Charles. 2002. Guide for beginning fossil hunters. Illinois State Geological Survey, Champaign, Illinois. Geoscience Education Series 15. 49 pp. Frankie, Wayne. 2004. Guide to rocks and minerals of Illinois. Illinois State Geological Survey, Champaign, Illinois. Geoscience Education Series 16. 71 pp. Killey, Myrna M. 1998. Illinois’ ice age legacy. Illinois State Geological Survey, Champaign, Illinois. Geoscience Education Series 14. 67 pp. Much of the material in this book is adapted from the Illinois State Geological Survey’s (ISGS) Guide for Beginning Fossil Hunters. Special thanks are given to Charles Collinson, former ISGS geologist, for the use of his fossil illustrations. Equal opportunity to participate in programs of the Illinois Department of Natural Resources (IDNR) and those funded by the U.S. Fish and Wildlife Service and other agencies is available to all individuals regardless of race, sex, national origin, disability, age, reli-gion or other non-merit factors. -
Brains of Primitive Chordates 439
Brains of Primitive Chordates 439 Brains of Primitive Chordates J C Glover, University of Oslo, Oslo, Norway although providing a more direct link to the evolu- B Fritzsch, Creighton University, Omaha, NE, USA tionary clock, is nevertheless hampered by differing ã 2009 Elsevier Ltd. All rights reserved. rates of evolution, both among species and among genes, and a still largely deficient fossil record. Until recently, it was widely accepted, both on morpholog- ical and molecular grounds, that cephalochordates Introduction and craniates were sister taxons, with urochordates Craniates (which include the sister taxa vertebrata being more distant craniate relatives and with hemi- and hyperotreti, or hagfishes) represent the most chordates being more closely related to echinoderms complex organisms in the chordate phylum, particu- (Figure 1(a)). The molecular data only weakly sup- larly with respect to the organization and function of ported a coherent chordate taxon, however, indicat- the central nervous system. How brain complexity ing that apparent morphological similarities among has arisen during evolution is one of the most chordates are imposed on deep divisions among the fascinating questions facing modern science, and it extant deuterostome taxa. Recent analysis of a sub- speaks directly to the more philosophical question stantially larger number of genes has reversed the of what makes us human. Considerable interest has positions of cephalochordates and urochordates, pro- therefore been directed toward understanding the moting the latter to the most closely related craniate genetic and developmental underpinnings of nervous relatives (Figure 1(b)). system organization in our more ‘primitive’ chordate relatives, in the search for the origins of the vertebrate Comparative Appearance of Brains, brain in a common chordate ancestor. -
The Origins of Chordate Larvae Donald I Williamson* Marine Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
lopmen ve ta e l B Williamson, Cell Dev Biol 2012, 1:1 D io & l l o l g DOI: 10.4172/2168-9296.1000101 e y C Cell & Developmental Biology ISSN: 2168-9296 Research Article Open Access The Origins of Chordate Larvae Donald I Williamson* Marine Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom Abstract The larval transfer hypothesis states that larvae originated as adults in other taxa and their genomes were transferred by hybridization. It contests the view that larvae and corresponding adults evolved from common ancestors. The present paper reviews the life histories of chordates, and it interprets them in terms of the larval transfer hypothesis. It is the first paper to apply the hypothesis to craniates. I claim that the larvae of tunicates were acquired from adult larvaceans, the larvae of lampreys from adult cephalochordates, the larvae of lungfishes from adult craniate tadpoles, and the larvae of ray-finned fishes from other ray-finned fishes in different families. The occurrence of larvae in some fishes and their absence in others is correlated with reproductive behavior. Adult amphibians evolved from adult fishes, but larval amphibians did not evolve from either adult or larval fishes. I submit that [1] early amphibians had no larvae and that several families of urodeles and one subfamily of anurans have retained direct development, [2] the tadpole larvae of anurans and urodeles were acquired separately from different Mesozoic adult tadpoles, and [3] the post-tadpole larvae of salamanders were acquired from adults of other urodeles. Reptiles, birds and mammals probably evolved from amphibians that never acquired larvae. -
Origin and Beyond
EVOLUTION ORIGIN ANDBEYOND Gould, who alerted him to the fact the Galapagos finches ORIGIN AND BEYOND were distinct but closely related species. Darwin investigated ALFRED RUSSEL WALLACE (1823–1913) the breeding and artificial selection of domesticated animals, and learned about species, time, and the fossil record from despite the inspiration and wealth of data he had gathered during his years aboard the Alfred Russel Wallace was a school teacher and naturalist who gave up teaching the anatomist Richard Owen, who had worked on many of to earn his living as a professional collector of exotic plants and animals from beagle, darwin took many years to formulate his theory and ready it for publication – Darwin’s vertebrate specimens and, in 1842, had “invented” the tropics. He collected extensively in South America, and from 1854 in the so long, in fact, that he was almost beaten to publication. nevertheless, when it dinosaurs as a separate category of reptiles. islands of the Malay archipelago. From these experiences, Wallace realized By 1842, Darwin’s evolutionary ideas were sufficiently emerged, darwin’s work had a profound effect. that species exist in variant advanced for him to produce a 35-page sketch and, by forms and that changes in 1844, a 250-page synthesis, a copy of which he sent in 1847 the environment could lead During a long life, Charles After his five-year round the world voyage, Darwin arrived Darwin saw himself largely as a geologist, and published to the botanist, Joseph Dalton Hooker. This trusted friend to the loss of any ill-adapted Darwin wrote numerous back at the family home in Shrewsbury on 5 October 1836. -
Constraints on the Timescale of Animal Evolutionary History
Palaeontologia Electronica palaeo-electronica.org Constraints on the timescale of animal evolutionary history Michael J. Benton, Philip C.J. Donoghue, Robert J. Asher, Matt Friedman, Thomas J. Near, and Jakob Vinther ABSTRACT Dating the tree of life is a core endeavor in evolutionary biology. Rates of evolution are fundamental to nearly every evolutionary model and process. Rates need dates. There is much debate on the most appropriate and reasonable ways in which to date the tree of life, and recent work has highlighted some confusions and complexities that can be avoided. Whether phylogenetic trees are dated after they have been estab- lished, or as part of the process of tree finding, practitioners need to know which cali- brations to use. We emphasize the importance of identifying crown (not stem) fossils, levels of confidence in their attribution to the crown, current chronostratigraphic preci- sion, the primacy of the host geological formation and asymmetric confidence intervals. Here we present calibrations for 88 key nodes across the phylogeny of animals, rang- ing from the root of Metazoa to the last common ancestor of Homo sapiens. Close attention to detail is constantly required: for example, the classic bird-mammal date (base of crown Amniota) has often been given as 310-315 Ma; the 2014 international time scale indicates a minimum age of 318 Ma. Michael J. Benton. School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, U.K. [email protected] Philip C.J. Donoghue. School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, U.K. [email protected] Robert J. -
Primitive Soft-Bodied Cephalopods from the Cambrian
ACCEPTED DRAFT Please note that this is not the final manuscript version. Links to the published manuscript, figures, and supplementary information can be found at http://individual.utoronto.ca/martinsmith/nectocaris.html doi: 10.1038/nature09068 Smith & Caron 2010, Page 1 Primitive soft-bodied cephalopods from the Cambrian Martin R. Smith 1, 2* & Jean-Bernard Caron 2, 1 1Departent of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord Street, Ontario, M5S 3G5, Canada 2Department of Palaeobiology, Royal Ontario Museum, 100 Queen ’s Park, Toronto, Ontario M5S 2C6, Canada *Author for correspondence The exquisite preservation of soft-bodied animals in Burgess Shale-type deposits provides important clues into the early evolution of body plans that emerged during the Cambrian explosion 1. Until now, such deposits have remained silent regarding the early evolution of extant molluscan lineages – in particular the cephalopods. Nautiloids, traditionally considered basal within the cephalopods, are generally depicted as evolving from a creeping Cambrian ancestor whose dorsal shell afforded protection and buoyancy 2. Whilst nautiloid-like shells occur from the Late Cambrian onwards, the fossil record provides little constraint on this model, or indeed on the early evolution of cephalopods. Here, we reinterpret the problematic Middle Cambrian animal Nectocaris pteryx 3, 4 as a primitive (i.e. stem-group), non-mineralized cephalopod, based on new material from the Burgess Shale. Together with Nectocaris, the problematic Lower Cambrian taxa Petalilium 5 and (probably) Vetustovermis 6, 7 form a distinctive clade, Nectocarididae, characterized by an open axial cavity with paired gills, wide lateral fins, a single pair of long, prehensile tentacles, a pair of non-faceted eyes on short stalks, and a large, flexible anterior funnel. -
Contributions in BIOLOGY and GEOLOGY
MILWAUKEE PUBLIC MUSEUM Contributions In BIOLOGY and GEOLOGY Number 51 November 29, 1982 A Compendium of Fossil Marine Families J. John Sepkoski, Jr. MILWAUKEE PUBLIC MUSEUM Contributions in BIOLOGY and GEOLOGY Number 51 November 29, 1982 A COMPENDIUM OF FOSSIL MARINE FAMILIES J. JOHN SEPKOSKI, JR. Department of the Geophysical Sciences University of Chicago REVIEWERS FOR THIS PUBLICATION: Robert Gernant, University of Wisconsin-Milwaukee David M. Raup, Field Museum of Natural History Frederick R. Schram, San Diego Natural History Museum Peter M. Sheehan, Milwaukee Public Museum ISBN 0-893260-081-9 Milwaukee Public Museum Press Published by the Order of the Board of Trustees CONTENTS Abstract ---- ---------- -- - ----------------------- 2 Introduction -- --- -- ------ - - - ------- - ----------- - - - 2 Compendium ----------------------------- -- ------ 6 Protozoa ----- - ------- - - - -- -- - -------- - ------ - 6 Porifera------------- --- ---------------------- 9 Archaeocyatha -- - ------ - ------ - - -- ---------- - - - - 14 Coelenterata -- - -- --- -- - - -- - - - - -- - -- - -- - - -- -- - -- 17 Platyhelminthes - - -- - - - -- - - -- - -- - -- - -- -- --- - - - - - - 24 Rhynchocoela - ---- - - - - ---- --- ---- - - ----------- - 24 Priapulida ------ ---- - - - - -- - - -- - ------ - -- ------ 24 Nematoda - -- - --- --- -- - -- --- - -- --- ---- -- - - -- -- 24 Mollusca ------------- --- --------------- ------ 24 Sipunculida ---------- --- ------------ ---- -- --- - 46 Echiurida ------ - --- - - - - - --- --- - -- --- - -- - - --- -
Proceedings of the Open University Geological Society
Proceedings of the Open University Geological Society Volume 4 2018 Including lecture articles from the AGM 2017, the Milton Keynes Symposium 2017, OUGS Members’ field trip reports, the Annual Report for 2017, and the 2017 Moyra Eldridge Photographic Competition winning and highly commended photographs Edited and designed by: Dr David M. Jones 41 Blackburn Way, Godalming, Surrey GU7 1JY e-mail: [email protected] The Open University Geological Society (OUGS) and its Proceedings Editor accept no responsibility for breach of copyright. Copyright for the work remains with the authors, but copyright for the published articles is that of the OUGS. ISSN 2058-5209 © Copyright reserved Proceedings of the OUGS 4 2018; published 2018; printed by Hobbs the Printers Ltd, Totton, Hampshire Evolution of life on land: how new Scottish fossils are re-writing our under- standing of this important transition Dr Tim Kearsey BGS Edinburgh Romer’s gap — a hole in our understanding t has long been understood that at some point in the evolution Meanwhile at a quarry called East Kirkton Quarry near Iof vertebrates there was a transition point where they moved Edinburgh in Scotland vertebrate fossils were discovered that are from mainly subsiding in water to living on land. However, until 10 million years younger than the Greenland fossils. These include recently there had been no fossil evidence that documented how Westlothiana, which is thought to be the first amniote (egg-layer) vertebrate life stepped from water to land. This significant hole in or possibly early reptile (Smithson and Rolfe 1990) and scientific knowledge of evolution is referred to as Romer’s gap Balanerpeton an extinct genus of temnospondyl amphibian. -
Copyrighted Material
06_250317 part1-3.qxd 12/13/05 7:32 PM Page 15 Phylum Chordata Chordates are placed in the superphylum Deuterostomia. The possible rela- tionships of the chordates and deuterostomes to other metazoans are dis- cussed in Halanych (2004). He restricts the taxon of deuterostomes to the chordates and their proposed immediate sister group, a taxon comprising the hemichordates, echinoderms, and the wormlike Xenoturbella. The phylum Chordata has been used by most recent workers to encompass members of the subphyla Urochordata (tunicates or sea-squirts), Cephalochordata (lancelets), and Craniata (fishes, amphibians, reptiles, birds, and mammals). The Cephalochordata and Craniata form a mono- phyletic group (e.g., Cameron et al., 2000; Halanych, 2004). Much disagree- ment exists concerning the interrelationships and classification of the Chordata, and the inclusion of the urochordates as sister to the cephalochor- dates and craniates is not as broadly held as the sister-group relationship of cephalochordates and craniates (Halanych, 2004). Many excitingCOPYRIGHTED fossil finds in recent years MATERIAL reveal what the first fishes may have looked like, and these finds push the fossil record of fishes back into the early Cambrian, far further back than previously known. There is still much difference of opinion on the phylogenetic position of these new Cambrian species, and many new discoveries and changes in early fish systematics may be expected over the next decade. As noted by Halanych (2004), D.-G. (D.) Shu and collaborators have discovered fossil ascidians (e.g., Cheungkongella), cephalochordate-like yunnanozoans (Haikouella and Yunnanozoon), and jaw- less craniates (Myllokunmingia, and its junior synonym Haikouichthys) over the 15 06_250317 part1-3.qxd 12/13/05 7:32 PM Page 16 16 Fishes of the World last few years that push the origins of these three major taxa at least into the Lower Cambrian (approximately 530–540 million years ago). -
Testing the Quality of the Fossil Record by Groups and by Major Habitats
Histo-icalBiology, 1996, Vol 12,pp I 1I-157 © 1996 OPA (Overseas Publishers Association) Reprints available directly from the publisher Amsterdam B V Published in The Netherlands Photocopying available by license only By Harwood Academic Publishers GmbH Printed in Malaysia TESTING THE QUALITY OF THE FOSSIL RECORD BY GROUPS AND BY MAJOR HABITATS MICHAEL J BENTON and REBECCA HITCHIN Department of Geology, University of Bristol, Bristol, B 58 IRJ, United Kingdom (Received February 9 1996; in final form March 25, 1996) The evolution of life is a form of history and, as Karl Popper pointed out, that makes much of palaeontology and evolutionary biology metaphysical and not scientific, since direct testing is not possible: history cannot be re-run However, it is possible to cross-compare three sources of data on phylogeny stratigraphic, cladistic, and molecular Three metrics for comparing cladograms with stratigraphic information allow cross-testing of () the order of branching with the stratigraphic order of fossils, and of (2) the relative amount of cladistically-implied gap in proportion to known fossil record. Results of the metrics, based upon a data set of 376 cladograms, show that there are statistically significant differences in the results for echinoderms, fishes, and tetrapods Matching of rank- order data on stratigraphic age of first appearances and branching points in cladograms, using Spearman Rank Correlation (SRC), is poorer than reported before, with only 148 of the 376 cladograms tested (39 %) showing statistically significant matching Tests of the relative amount of cladistically-implied gap, using the Relative Completeness Index (RCI), indicated excellent results, with 288 of the cladograms tested (77 %) having records more than 50% complete.