DOCSLIB.ORG

Recent Progress in Paleontological Methods for Dating the Tree of Life

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Recent Progress in Paleontological Methods for Dating the Tree of Life REVIEW ARTICLE published: 13 July 2012 doi: 10.3389/fgene.2012.00130 Recent progress in paleontological methods for dating theTree of Life Michel Laurin* UMR 7207, CNRS/MNHN/UPMC, Earth History Department, Muséum National d’Histoire Naturelle, Paris, France Edited by: Dating the Tree of Life (TOL) has become a major goal of biological research. Beyond the Alex Pyron, The George Washington intrinsic interest of reconstructing the history of taxonomic diversification, time-calibrated University, USA trees (timetrees for short, as used throughout below) are required in many types of com- Reviewed by: parative analyses, where branch lengths are used to assess the conservation importance Michael S. Lee, South Australian Museum, Australia of lineages, correlation between characters, or to assess phylogenetic niche conservatism, Alex Pyron, The George Washington among other uses. Improvements in dating the TOL would thus benefit large segments of University, USA the biological community, ranging from conservation biology and ecology through func- Chris Organ, Harvard University, USA tional biology and paleontology. Recently, progress has been made on several fronts: *Correspondence: in compiling databases and supertrees incorporating paleontological data, in computing Michel Laurin, UMR 7207, CNRS/MNHN/UPMC, Earth History confidence intervals on the true stratigraphic range of taxa, and in using birth-and-death Department, Muséum National processes to assess the probability distribution of the time of origin of specified taxa. d’Histoire Naturelle, 43 rue Buffon, Combined paleontological and molecular dating has also progressed through the inser- CP 48, 75005 Paris, France. e-mail: [email protected] tion of extinct taxa into data matrices, which allows incorporation of their phylogenetic uncertainty into the dating analysis. Keywords: phylogenetics, molecular dating, molecular clock, paleontological dating, stratigraphic range, fossil record, confidence intervals INTRODUCTION much biodiversity as possible), but all these approaches are prob- WHY DATE THE TREE OF LIFE? lematic to various extents. There is no universally accepted species Some of the most basic questions about the evolution of life con- concept, despite repeated attempts to unify species concepts (e.g., cern the chronology of events. When did a given taxon appear? de Queiroz, 1998). As such, the entities that we call “species” and When did it diversify? Was its diversification slow and gradual, or that are registered into various databases are not ontologically did it occur in bursts (evolutionary radiations), and if so, when comparable; some are clades, some are reproductive communities, were these bursts, and what caused them? Answering such ques- some are evolutionary lineages, others are phenetic clusters, and tions is important not only to satisfy our intellectual curiosity yet others belong to two or more of these categories. This problem about the history of life, but also to allow sophisticated analyses in has far-reaching consequences for conservation biology (Bertrand other fields. et al., 2006), and it has hampered developments of a new, phylo- Dating the Tree of Life (TOL) has become a major goal of bio- genetic code of biological nomenclature for species (Laurin and logical research, as shown by various well-funded initiatives (at Cantino, 2007). Taxa belonging to higher categories are even more least in the USA), such as the Assembling the Tree of Life program problematic in conservation biology because, like species, they of the National Science Foundation (http://www.nsf.gov/funding/ share no objective properties, and they often differ rather strongly pgm_summ.jsp?pims_id=5129), which has distributed over US $ in many important aspects, such as geological age of origin, num- 57 000 000 since 2006. Dating the TOL has also been the exclu- ber of included species, or phenotypic variability (Laurin, 2005, sive subject of a large, recent edited book (Hedges and Kumar, 2008; Bertrand et al., 2006). The most objective solution that has 2009a), and some molecular systematics laboratories now special- been advocated (and widely applied) to circumvent all these prob- ize in this task. This interest in dating the TOL is not surprising lems is to use phylogenetic diversity (the sum of branch lengths because beyond the intrinsic goal of reconstructing the history of expressed as time), as this captures the sum of the unique his- taxonomic diversification, timetrees are required in many types of tory of a given clade, or of a given fauna or flora of a region comparative analyses. In fact, time data are so useful that Avise and (Faith, 1992). Liu (2011) have suggested to systematically add this information In comparative biology, timetrees have become essential since to taxon names. we have realized that comparative data are not statistically inde- These advances in evolutionary biology, which require time- pendent from each other. This is because closely related taxa trees, have revolutionized modern science by allowing more tend to resemble each other more closely than distantly related rigorous analyses. For instance, conservation studies previously taxa. Thus, all modern comparative techniques for inter-specific used species counts (at best) or higher taxon count (of genera, fam- datasets incorporate phylogenetic information, ideally in the form ilies, or even orders) to assess the biodiversity of various regions of timetrees. The interest of this approach is demonstrated by the (hotspots or simply areas that could be protected to preserve as high number of ISI citations (1371) of the paper by Felsenstein www.frontiersin.org July 2012 | Volume 3 | Article 130 | 1 “fgene-03-00130” — 2012/7/12 — 15:10 — page1—#1 Laurin Recent Progress in paleontological dating (1985a) that presented the method of phylogenetically inde- and lissamphibians (Ruta and Coates, 2007; Anderson et al., 2008; pendent contrasts (ISI databanks consulted on March 4, 2011). Marjanovi´c and Laurin, 2009). Similarly, the related method called phylogenetic generalized least More recently, use of the fossil record has increasingly been squares (PGLS; Martins and Hansen, 1997; Pagel, 1997) is increas- complemented by molecular timetrees, a change allowed by the ingly used in such studies (e.g., Spoor et al., 2007; Organ et al., tremendous growth of molecular phylogenetics in the last two 2011a,b). Branch lengths are also needed to study phylogenetic decades (e.g., Sanderson, 2003; Hedges and Kumar, 2009a), even niche conservatism (Patterson and Givnish,2002; Desdevises et al., though the roots of molecular dating hark back to the 1960s 2003; Losos, 2008), evolutionary trends from paleontological data (Zuckerkandl and Pauling, 1962). The basic principle of molecular (Laurin, 2010a), or to determine ancestral conditions through dating rests on inferring how much molecular change has occurred methods such as squared-change parsimony (e.g., Laurin, 2004; on each branch of the reconstructed tree (or trees, when Bayesian Finarelli and Flynn, 2006), Maximum Likelihood (Pagel, 1999), or methods are used). This is not straightforward because multiple Bayesian inference (e.g., Organ et al., 2011a,b). changes can occur at a given nucleotide site, and given that there Various evolutionary problems, such as the search of a corre- are only four possible states (A, T, C, or G), a given site may revert lation between past climatic changes or geological events (i.e., the to its initial condition. Furthermore, all sites do not evolve at the break-up of Pangea) and taxonomic or phenotypic diversification, same speed; some genes evolve faster than others, mitochondrial require timetrees to be meaningfully studied (e.g., Paradis, 2004; genes tend to evolve faster than most nuclear genes, silent portions San Mauro et al., 2005). Thus, timetrees are at the core of several of the genome tend to evolve faster than functionally important biological fields, so any project that would significantly improve portions, and third codon positions evolve faster than first and sec- how they are built would benefit a large segment of the biological ond codon positions because many changes in the third position community. result in the same amino acid. Thus, molecular biologists have From an economic perspective, the applications of timetrees developed various evolutionary models that attempt to account in conservation biology (Faith, 1992), through better-informed for these factors, as well as sophisticated methods to select the choices in conservation priorities (of regions or taxa), are prob- best-supported model (e.g., Posada, 2008). ably the most important. Indeed, the twenty-first century faces The resulting tree is usually not ultrametric because each lin- a major biodiversity crisis and may well be the “century of eage evolves at its own rate; thus, the tips (extant terminal taxa) extinction” (Dubois, 2003), in addition to (and partly because are each at a slightly different patristic distance from the root of) facing climate change caused by greenhouse gas emissions. of the tree. The differences in height represent deviations from Biodiversity is important for the maintenance of ecosystems, the hypothesis of a molecular clock. The tree can be ultrametri- and the crucial role of “ecosystem services” (in maintaining a cized using various algorithms, which, in a best-case scenario, climate favorable to agriculture and human health, in absorb- results in a tree in which branch lengths are proportional to ing greenhouse gases, etc.) are
Load more

Recommended publications
  • Para Conhecer a Terra: Memórias E Notícias De Geociências No Espaço Lusófono Autor(Es): Lopes, F.C. (Coord.); Andrade, A. I
    Para conhecer a Terra: memórias e notícias de Geociências no espaço lusófono Lopes, F.C. (coord.); Andrade, A. I. (coord.); Henriques, M. H. (coord.); Autor(es): Quinta-Ferreira, M. (coord.); Reis, R. Pena dos (coord.); Barata, M. T. (coord.) Publicado por: Imprensa da Universidade de Coimbra URL persistente: URI:http://hdl.handle.net/10316.2/24406 DOI: DOI:http://dx.doi.org/10.14195/978-989-26-0534-0 Accessed : 11-Oct-2021 03:52:55 A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso. pombalina.uc.pt digitalis.uc.pt 9 789892 605111 Série Documentos A presente obra reúne um conjunto de contribuições apresentadas no I Congresso Imprensa da Universidade de Coimbra Internacional de Geociências na CPLP, que decorreu de 14 a 16 de maio de 2012 no Coimbra University Press Auditório da Reitoria da Universidade de Coimbra.
    [Show full text]
  • Biostratigraphy and Paleoecology of Continental Tertiary Vertebrate Faunas in the Lower Rhine Embayment (NW-Germany)
    Netherlands Journal of Geosciences / Geologie en Mijnbouw 81 (2): 177-183 (2002) Biostratigraphy and paleoecology of continental Tertiary vertebrate faunas in the Lower Rhine Embayment (NW-Germany) Th. Mors Naturhistoriska Riksmuseet/Swedish Museum of Natural History, Department of Palaeozoology, P.O. Box 50007, SE-104 05 Stockholm, Sweden; e-mail: [email protected] Manuscript received: October 2000; accepted: January 2002 ^ Abstract This paper discusses the faunal content, the mammal biostratigraphy, and the environmental ecology of three important con­ tinental Tertiary vertebrate faunas from the Lower Rhine Embayment. The sites investigated are Rott (MP 30, Late Oligocene), Hambach 6C (MN 5, Middle Miocene), Frechen and Hambach 11 (both MN 16, Late Pliocene). Comparative analysis of the entire faunas shows the assemblages to exhibit many conformities in their general composition, presumably re­ sulting from their preference for wet lowlands. It appears that very similar environmental conditions for vertebrates reoc- curred during at least 20 Ma although the sites are located in a tectonically active region with high subsidence rates. Differ­ ences in the faunal composition are partly due to local differences in the depositional environment of the sites: lake deposits at the margin of the embayment (Rott), coal swamp and estuarine conditions in the centre of the embayment (Hambach 6C), and flood plain environments with small rivulets (Frechen and Hambach 1 l).The composition of the faunal assemblages (di­ versity and taxonomy) also documents faunal turnovers with extinctions and immigrations (Oligocene/Miocene and post- Middle Miocene), as a result of changing climate conditions. Additional vertebrate faunal data were retrieved from two new assemblages collected from younger strata at the Hambach mine (Hambach 11C and 14).
    [Show full text]
  • Ontogenetic Evidence for the Paleozoic Ancestry of Salamanders
    EVOLUTION & DEVELOPMENT 5:3, 314–324 (2003) Ontogenetic evidence for the Paleozoic ancestry of salamanders Rainer R. Schocha and Robert L. Carrollb aStaatlilches Museum für Naturkunde, Rosenstein 1, D-70191 Stuttgart, Germany bRedpath Museum, McGill University, Montréal, Québec, Canada, H3A 2K6 Authors for correspondence (e-mail: [email protected], [email protected]) SUMMARY The phylogenetic positions of frogs, sala- tire developmental sequence from hatching to metamor- manders, and caecilians have been difficult to establish. phosis is revealed in an assemblage of over 600 Data matrices based primarily on Paleozoic taxa support a specimens from a single locality, all belonging to the genus monophyletic origin of all Lissamphibia but have resulted in Apateon. Apateon forms the most speciose genus of the widely divergent hypotheses of the nature of their common neotenic temnospondyl family Branchiosauridae. The se- ancestor. Analysis that concentrates on the character quence of ossification of individual bones and the changing states of the stem taxa of the extant orders, in contrast, configuration of the skull closely parallel those observed in suggests a polyphyletic origin from divergent Paleozoic the development of primitive living salamanders. These clades. Comparison of patterns of larval development in fossils provide a model of how derived features of the sala- Paleozoic and modern amphibians provides a means to mander skull may have evolved in the context of feeding test previous phylogenies based primarily on adult charac- specializations that appeared in early larval stages of mem- teristics. This proves to be highly informative in the case of bers of the Branchiosauridae. Larvae of Apateon share the origin of salamanders.
    [Show full text]
  • BOA2.1 Caecilian Biology and Natural History.Key
    The Biology of Amphibians @ Agnes Scott College Mark Mandica Executive Director The Amphibian Foundation [email protected] 678 379 TOAD (8623) 2.1: Introduction to Caecilians Microcaecilia dermatophaga Synapomorphies of Lissamphibia There are more than 20 synapomorphies (shared characters) uniting the group Lissamphibia Synapomorphies of Lissamphibia Integumen is Glandular Synapomorphies of Lissamphibia Glandular Skin, with 2 main types of glands. Mucous Glands Aid in cutaneous respiration, reproduction, thermoregulation and defense. Granular Glands Secrete toxic and/or noxious compounds and aid in defense Synapomorphies of Lissamphibia Pedicellate Teeth crown (dentine, with enamel covering) gum line suture (fibrous connective tissue, where tooth can break off) basal element (dentine) Synapomorphies of Lissamphibia Sacral Vertebrae Sacral Vertebrae Connects pelvic girdle to The spine. Amphibians have no more than one sacral vertebrae (caecilians have none) Synapomorphies of Lissamphibia Amphicoelus Vertebrae Synapomorphies of Lissamphibia Opercular apparatus Unique to amphibians and Operculum part of the sound conducting mechanism Synapomorphies of Lissamphibia Fat Bodies Surrounding Gonads Fat Bodies Insulate gonads Evolution of Amphibians † † † † Actinopterygian Coelacanth, Tetrapodomorpha †Amniota *Gerobatrachus (Ray-fin Fishes) Lungfish (stem-tetrapods) (Reptiles, Mammals)Lepospondyls † (’frogomander’) Eocaecilia GymnophionaKaraurus Caudata Triadobatrachus Anura (including Apoda Urodela Prosalirus †) Salientia Batrachia Lissamphibia
    [Show full text]
  • Reptile Family Tree
    Reptile Family Tree - Peters 2015 Distribution of Scales, Scutes, Hair and Feathers Fish scales 100 Ichthyostega Eldeceeon 1990.7.1 Pederpes 91 Eldeceeon holotype Gephyrostegus watsoni Eryops 67 Solenodonsaurus 87 Proterogyrinus 85 100 Chroniosaurus Eoherpeton 94 72 Chroniosaurus PIN3585/124 98 Seymouria Chroniosuchus Kotlassia 58 94 Westlothiana Casineria Utegenia 84 Brouffia 95 78 Amphibamus 71 93 77 Coelostegus Cacops Paleothyris Adelospondylus 91 78 82 99 Hylonomus 100 Brachydectes Protorothyris MCZ1532 Eocaecilia 95 91 Protorothyris CM 8617 77 95 Doleserpeton 98 Gerobatrachus Protorothyris MCZ 2149 Rana 86 52 Microbrachis 92 Elliotsmithia Pantylus 93 Apsisaurus 83 92 Anthracodromeus 84 85 Aerosaurus 95 85 Utaherpeton 82 Varanodon 95 Tuditanus 91 98 61 90 Eoserpeton Varanops Diplocaulus Varanosaurus FMNH PR 1760 88 100 Sauropleura Varanosaurus BSPHM 1901 XV20 78 Ptyonius 98 89 Archaeothyris Scincosaurus 77 84 Ophiacodon 95 Micraroter 79 98 Batropetes Rhynchonkos Cutleria 59 Nikkasaurus 95 54 Biarmosuchus Silvanerpeton 72 Titanophoneus Gephyrostegeus bohemicus 96 Procynosuchus 68 100 Megazostrodon Mammal 88 Homo sapiens 100 66 Stenocybus hair 91 94 IVPP V18117 69 Galechirus 69 97 62 Suminia Niaftasuchus 65 Microurania 98 Urumqia 91 Bruktererpeton 65 IVPP V 18120 85 Venjukovia 98 100 Thuringothyris MNG 7729 Thuringothyris MNG 10183 100 Eodicynodon Dicynodon 91 Cephalerpeton 54 Reiszorhinus Haptodus 62 Concordia KUVP 8702a 95 59 Ianthasaurus 87 87 Concordia KUVP 96/95 85 Edaphosaurus Romeria primus 87 Glaucosaurus Romeria texana Secodontosaurus
    [Show full text]
  • A New Osteolepidid Fish From
    Rea. West. Aust. MU8. 1985, 12(3): 361-377 ANew Osteolepidid Fish from the Upper Devonian Gogo Formation, Western Australia J.A. Long* Abstract A new osteolepidid crossopterygian, Gogonasus andrewsi gen. et sp. nov., is des­ cribed from a single fronto-ethmoidal shield and associated ethmosphenoid, from the Late Devonian (Frasnian) Gogo Formation, Western Australia. Gogonasus is is distinguished from other osteolepids by the shape and proportions of the fronto­ ethmoidal shield, absence of palatal fenestrae, well developed basipterygoid pro­ cesses and moderately broad parasphenoid. The family Osteolepididae is found to be paraphyletic, with Gogonasus being regarded as a plesiomorphic osteolepidid at a similar level of organisation to Thursius. Introduction Much has been published on the well-preserved Late Devonian fish fauna from the Gogo Formation, Western Australia, although to date all the papers describing fish have been on placoderms (Miles 1971; Miles and Dennis 1979; Dennis and Miles 1979-1983; Young 1984), palaeoniscoids (Gardiner 1973, 1984; Gardiner and Bartram 1977) or dipnoans (Miles 1977; Campbell and Barwick 1982a, 1982b, 1983, 1984a). This paper describes the only osteolepiform from the fauna (Gardiner and Miles 1975), a small snout with associated braincase, ANU 21885, housed in the Geology Department, Australian National University. The specimen, collected by the Australian National University on the 1967 Gogo Expedition, was prepared by Dr S.M. Andrews (Royal Scottish Museum) and later returned to the ANU. Onychodus is the only other crossopterygian in the fauna. In its proportions and palatal structure the new specimen provides some additional new points of the anatomy of osteolepiforms. Few Devonian crossopte­ rygians are known from Australia, and so the specimen is significant in having resemblances to typical Northern Hemisphere species.
    [Show full text]
  • 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.
    [Show full text]
  • Baez NHM 1997.Pdf (3.622Mb)
    HERP QL 668 B33 l':iif;,O0i.U'.Z06l("'^ ocxentxpc Papers Natural History Museum The University of Kansas 29 October 1997 Number 4:1^1 Redescription of the Paleogene Shelania pascuali from Patagonia and Its Bearing on the Relationships of Fossil and Recent Pipoid Frogs >. By o O Ana Maria BAez^ and Linda Trueb- o ^Departamento de Geologia, FacuUad de Ciencias Exactas, Universidad de 0) w >. > t- Buenos Aires, Pabellon II, Ciudad Universitaria, 1428 Buenos Aires, Argentina CO !-> >^ ^ £ -^ '^Division of Herpetology, Natural Histoiy Museum, and Department of P Kansas 66045-2454, J3 o, Systematics and Ecology, The University of Kansas, Lawrence, USA a o t3 o CO ^ t. CONTENTS ° CO I ABSTRACT 2 « RESUMEN 2 5S INTRODUCTION 2 Previous Paleontological Work 4 Acknowledgments 4 MATERIALS AND METHODS 5 General Methodology 5 Cladistic Methodology 5 Specimens Examined 6 STRATIGRAPHIC PROVENANCE AND AGE OF MATERIAL 6 REDESCRIPTION OF SHELANIA 8 ANALYSIS OF CHARACTERS 16 RESULTS 31 DISCUSSION 35 Taxonomic Considerations 35 Characters 36 LITERATURE CITED 37 APPENDIX 40 © Natural History Museum, The University of Kansas ISSN No. 1094-0782 — 2 Scientific Papers, Natural History Museum, The University of Kansas 1960, is redescribed on the basis of a series of 30 recently I ABSTIMCT Shdania pascuali Casamiquela, .'-\ ' . discovered specimens, which range in estimated snout-vent length from 30-100 mm, from the Paleo- y ' gene of Patagonia. This large pipoid anuran is distinguished by possessing a long, narrow braincase; an hourglass-shaped frontoparietal; a robust antorbital process on the edentate maxilla; long, straight {/) '/^ I ilia that describe a V-shape in dorsal profile; and a trunk that is long relative to the lengths of the head and limbs.
    [Show full text]
  • Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha)
    Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) by Richard Kissel A thesis submitted in conformity with the requirements for the degree of doctor of philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto © Copyright by Richard Kissel 2010 Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) Richard Kissel Doctor of Philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto 2010 Abstract Based on dental, cranial, and postcranial anatomy, members of the Permo-Carboniferous clade Diadectidae are generally regarded as the earliest tetrapods capable of processing high-fiber plant material; presented here is a review of diadectid morphology, phylogeny, taxonomy, and paleozoogeography. Phylogenetic analyses support the monophyly of Diadectidae within Diadectomorpha, the sister-group to Amniota, with Limnoscelis as the sister-taxon to Tseajaia + Diadectidae. Analysis of diadectid interrelationships of all known taxa for which adequate specimens and information are known—the first of its kind conducted—positions Ambedus pusillus as the sister-taxon to all other forms, with Diadectes sanmiguelensis, Orobates pabsti, Desmatodon hesperis, Diadectes absitus, and (Diadectes sideropelicus + Diadectes tenuitectes + Diasparactus zenos) representing progressively more derived taxa in a series of nested clades. In light of these results, it is recommended herein that the species Diadectes sanmiguelensis be referred to the new genus
    [Show full text]
  • 71St Annual Meeting Society of Vertebrate Paleontology Paris Las Vegas Las Vegas, Nevada, USA November 2 – 5, 2011 SESSION CONCURRENT SESSION CONCURRENT
    ISSN 1937-2809 online Journal of Supplement to the November 2011 Vertebrate Paleontology Vertebrate Society of Vertebrate Paleontology Society of Vertebrate 71st Annual Meeting Paleontology Society of Vertebrate Las Vegas Paris Nevada, USA Las Vegas, November 2 – 5, 2011 Program and Abstracts Society of Vertebrate Paleontology 71st Annual Meeting Program and Abstracts COMMITTEE MEETING ROOM POSTER SESSION/ CONCURRENT CONCURRENT SESSION EXHIBITS SESSION COMMITTEE MEETING ROOMS AUCTION EVENT REGISTRATION, CONCURRENT MERCHANDISE SESSION LOUNGE, EDUCATION & OUTREACH SPEAKER READY COMMITTEE MEETING POSTER SESSION ROOM ROOM SOCIETY OF VERTEBRATE PALEONTOLOGY ABSTRACTS OF PAPERS SEVENTY-FIRST ANNUAL MEETING PARIS LAS VEGAS HOTEL LAS VEGAS, NV, USA NOVEMBER 2–5, 2011 HOST COMMITTEE Stephen Rowland, Co-Chair; Aubrey Bonde, Co-Chair; Joshua Bonde; David Elliott; Lee Hall; Jerry Harris; Andrew Milner; Eric Roberts EXECUTIVE COMMITTEE Philip Currie, President; Blaire Van Valkenburgh, Past President; Catherine Forster, Vice President; Christopher Bell, Secretary; Ted Vlamis, Treasurer; Julia Clarke, Member at Large; Kristina Curry Rogers, Member at Large; Lars Werdelin, Member at Large SYMPOSIUM CONVENORS Roger B.J. Benson, Richard J. Butler, Nadia B. Fröbisch, Hans C.E. Larsson, Mark A. Loewen, Philip D. Mannion, Jim I. Mead, Eric M. Roberts, Scott D. Sampson, Eric D. Scott, Kathleen Springer PROGRAM COMMITTEE Jonathan Bloch, Co-Chair; Anjali Goswami, Co-Chair; Jason Anderson; Paul Barrett; Brian Beatty; Kerin Claeson; Kristina Curry Rogers; Ted Daeschler; David Evans; David Fox; Nadia B. Fröbisch; Christian Kammerer; Johannes Müller; Emily Rayfield; William Sanders; Bruce Shockey; Mary Silcox; Michelle Stocker; Rebecca Terry November 2011—PROGRAM AND ABSTRACTS 1 Members and Friends of the Society of Vertebrate Paleontology, The Host Committee cordially welcomes you to the 71st Annual Meeting of the Society of Vertebrate Paleontology in Las Vegas.
    [Show full text]
  • Early Tetrapod Relationships Revisited
    Biol. Rev. (2003), 78, pp. 251–345. f Cambridge Philosophical Society 251 DOI: 10.1017/S1464793102006103 Printed in the United Kingdom Early tetrapod relationships revisited MARCELLO RUTA1*, MICHAEL I. COATES1 and DONALD L. J. QUICKE2 1 The Department of Organismal Biology and Anatomy, The University of Chicago, 1027 East 57th Street, Chicago, IL 60637-1508, USA ([email protected]; [email protected]) 2 Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire SL57PY, UK and Department of Entomology, The Natural History Museum, Cromwell Road, London SW75BD, UK ([email protected]) (Received 29 November 2001; revised 28 August 2002; accepted 2 September 2002) ABSTRACT In an attempt to investigate differences between the most widely discussed hypotheses of early tetrapod relation- ships, we assembled a new data matrix including 90 taxa coded for 319 cranial and postcranial characters. We have incorporated, where possible, original observations of numerous taxa spread throughout the major tetrapod clades. A stem-based (total-group) definition of Tetrapoda is preferred over apomorphy- and node-based (crown-group) definitions. This definition is operational, since it is based on a formal character analysis. A PAUP* search using a recently implemented version of the parsimony ratchet method yields 64 shortest trees. Differ- ences between these trees concern: (1) the internal relationships of aı¨stopods, the three selected species of which form a trichotomy; (2) the internal relationships of embolomeres, with Archeria
    [Show full text]
  • A Review of Neusibatrachus Wilferti, an Early Cretaceous Frog from the Montsec Range, Northeastern Spain
    A review of Neusibatrachus wilferti, an Early Cretaceous frog from the Montsec Range, northeastern Spain ANA M. BÁEZ and BORJA SANCHIZ Báez, A.M. and Sanchiz, B. 2007. A review of Neusibatrachus wilferti, an Early Cretaceous frog from the Montsec Range, northeastern Spain. Acta Palaeontologica Polonica 52 (3): 477–487. Neusibatrachus wilferti is an anuran from the late Berriasian–early Valanginian fossiliferous lacustrine limestones that are exposed in the eastern part of the Montsec Range, province of Lleida, Spain. It was originally described by Seiffert in 1972 and its phylogenetic position has since been discussed. Neusibatrachus has been considered an undeterminable fos− sil, an abnormal individual, or a primitive palaeobatrachid. Here we redescribe the only available specimen, and clarify features, such as absence of palatines, nine presacrals, and procoelous vertebral centra, that have been the subject of previ− ous debates. We consider the specimen to be a postmetamorphic individual and make developmental interpretations of some of its characters. In particular, we provide evidence of a living anuran (Rana iberica) that resembles Neusibatrachus in the development of intervertebral articulations. Neusibatrachus is considered a valid genus, which differs from other anurans, except for the pipoids, in the joint presence of an azygous frontoparietal and a parasphenoid lacking the subotic alae, although it differs from the pipoids in having nine presacral vertebrae. Morphological evidence indicates that Neusi− batrachus is related to Xenoanura, the pipoid branch in the living Amphibia Tree of Life based on molecular data. More− over, it might be a member of the pipoid clade proper, which presently includes the Pipidae, Rhinophrynidae, and several fossil taxa, including the Palaeobatrachidae, although the evidence is not conclusive.
    [Show full text]