The Evolutionary Paths to Diversity
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Relaxed Selection in the Wild
TREE-1109; No of Pages 10 Review Relaxed selection in the wild David C. Lahti1, Norman A. Johnson2, Beverly C. Ajie3, Sarah P. Otto4, Andrew P. Hendry5, Daniel T. Blumstein6, Richard G. Coss7, Kathleen Donohue8 and Susan A. Foster9 1 Department of Biology, University of Massachusetts, Amherst, MA 01003, USA 2 Department of Plant, Soil, and Insect Sciences, University of Massachusetts, Amherst, MA 01003, USA 3 Center for Population Biology, University of California, Davis, CA 95616, USA 4 Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada 5 Redpath Museum and Department of Biology, McGill University, Montreal, QC H3A 2K6, Canada 6 Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA 7 Department of Psychology, University of California, Davis, CA 95616, USA 8 Department of Biology, Duke University, Durham, NC 02138, USA 9 Department of Biology, Clark University, Worcester, MA 01610, USA Natural populations often experience the weakening or are often less clear than typical cases of trait evolution. removal of a source of selection that had been important When an environmental change results in strong selection in the maintenance of one or more traits. Here we refer to on a trait from a known source, a prediction for trait these situations as ‘relaxed selection,’ and review recent evolution often follows directly from this fact [2]. When studies that explore the effects of such changes on traits such a strong source of selection is removed, however, no in their ecological contexts. In a few systems, such as the clear prediction emerges. Rather, the likelihood of various loss of armor in stickleback, the genetic, developmental consequences can only be understood by integrating the and ecological bases of trait evolution are being discov- remaining sources of selection and processes at all levels of ered. -
The Phylogenetic Position of Ambiortus: Comparison with Other Mesozoic Birds from Asia1 J
ISSN 00310301, Paleontological Journal, 2013, Vol. 47, No. 11, pp. 1270–1281. © Pleiades Publishing, Ltd., 2013. The Phylogenetic Position of Ambiortus: Comparison with Other Mesozoic Birds from Asia1 J. K. O’Connora and N. V. Zelenkovb aKey Laboratory of Evolution and Systematics, Institute of Vertebrate Paleontology and Paleoanthropology, 142 Xizhimenwai Dajie, Beijing China 10044 bBorissiak Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya ul. 123, Moscow, 117997 Russia email: [email protected], [email protected] Received August 6, 2012 Abstract—Since the last description of the ornithurine bird Ambiortus dementjevi from Mongolia, a wealth of Early Cretaceous birds have been discovered in China. Here we provide a detailed comparison of the anatomy of Ambiortus relative to other known Early Cretaceous ornithuromorphs from the Chinese Jehol Group and Xiagou Formation. We include new information on Ambiortus from a previously undescribed slab preserving part of the sternum. Ambiortus is superficially similar to Gansus yumenensis from the Aptian Xiagou Forma tion but shares more morphological features with Yixianornis grabaui (Ornithuromorpha: Songlingorni thidae) from the Jiufotang Formation of the Jehol Group. In general, the mosaic pattern of character distri bution among early ornithuromorph taxa does not reveal obvious relationships between taxa. Ambiortus was placed in a large phylogenetic analysis of Mesozoic birds, which confirms morphological observations and places Ambiortus in a polytomy with Yixianornis and Gansus. Keywords: Ornithuromorpha, Ambiortus, osteology, phylogeny, Early Cretaceous, Mongolia DOI: 10.1134/S0031030113110063 1 INTRODUCTION and articulated partial skeleton, preserving several cervi cal and thoracic vertebrae, and parts of the left thoracic Ambiortus dementjevi Kurochkin, 1982 was one of girdle and wing (specimen PIN, nos. -
Anchiornis and Scansoriopterygidae
SpringerBriefs in Earth System Sciences SpringerBriefs South America and the Southern Hemisphere Series Editors Gerrit Lohmann Lawrence A. Mysak Justus Notholt Jorge Rabassa Vikram Unnithan For further volumes: http://www.springer.com/series/10032 Federico L. Agnolín · Fernando E. Novas Avian Ancestors A Review of the Phylogenetic Relationships of the Theropods Unenlagiidae, Microraptoria, Anchiornis and Scansoriopterygidae 1 3 Federico L. Agnolín “Félix de Azara”, Departamento de Ciencias Naturales Fundación de Historia Natural, CEBBAD, Universidad Maimónides Buenos Aires Argentina Fernando E. Novas CONICET, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” Buenos Aires Argentina ISSN 2191-589X ISSN 2191-5903 (electronic) ISBN 978-94-007-5636-6 ISBN 978-94-007-5637-3 (eBook) DOI 10.1007/978-94-007-5637-3 Springer Dordrecht Heidelberg New York London Library of Congress Control Number: 2012953463 © The Author(s) 2013 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. -
From the Late Cretaceous of Patagonia
AMEGHINIANA (Rev. Asoc. Paleontol. Argent.) - 40 (1): 119-122. Buenos Aires, 30-03-2003 ISSN0002-7014 NOTA PALEONTOLÓGICA A new specimen of Patagonykus puertai (Theropoda: Alvarezsauridae) from the Late Cretaceous of Patagonia Luis M. CHIAPPE1and Rodolfo A. CORIA2 Introduction Systematic paleontology With their short and robust forelimbs, highly ki- THEROPODA netic skulls, and a host of unique skeletal features, COELUROSAURIA alvarezsaurids are highly specialized Mesozoic ALVAREZSAURIDAEBonaparte, 1991 coelurosaurian theropods known from the Late Cretaceous of Asia, North, and South America Genus PatagonykusNovas, 1997a (Chiappe et al., 2002). Despite abundant and well- preserved material from the Gobi Desert of Patagonykussp. cf. P. puertaiNovas, 1997a Mongolia, the phylogenetic relationships of al- Figures 1 and 2 varezsaurids have remained unclear (Chiappe et Material. MCF-PVPH-102 (Museo Carmen Funes, al., 2002; Novas and Pol, 2002; Suzuki et al., 2002). Paleontología de Vertebrados; Plaza Huincul, The most basal alvarezsaurids are from South Neuquén, Argentina), an articulated phalanx 1 and 2 America and are limited to just two taxa from the (ungual) of the left manual digit I. Patagonian province of Neuquén (Argentina), Geographical provenance and geological horizon. Alvarezsaurus calvoi (Bonaparte, 1991) and Northern shore of Los Barriales lake, approximately Patagokykus puertai (Novas, 1997a), which although 80 km north Plaza Huincul. Because the specimen poorly represented are important because they was not collected by professionals, no precise strati- have been consistently interpreted as the most ple- graphic information is available; nonetheless, only siomorphic members of the group (Novas, 1996; the Late Cretaceous Neuquén Group outcrops in this Chiappe et al., 1998). area. Also, considering that the holotype specimen of Here we report on a second specimen of Patagonykus puertaiwas found in beds attributed to Patagonykus, which we assign to the species P. -
The Braincase, Brain and Palaeobiology of the Basal Sauropodomorph Dinosaur Thecodontosaurus Antiquus
applyparastyle “fig//caption/p[1]” parastyle “FigCapt” Zoological Journal of the Linnean Society, 2020, XX, 1–22. With 10 figures. Downloaded from https://academic.oup.com/zoolinnean/advance-article/doi/10.1093/zoolinnean/zlaa157/6032720 by University of Bristol Library user on 14 December 2020 The braincase, brain and palaeobiology of the basal sauropodomorph dinosaur Thecodontosaurus antiquus ANTONIO BALLELL1,*, J. LOGAN KING1, JAMES M. NEENAN2, EMILY J. RAYFIELD1 and MICHAEL J. BENTON1 1School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK 2Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK Received 27 May 2020; revised 15 October 2020; accepted for publication 26 October 2020 Sauropodomorph dinosaurs underwent drastic changes in their anatomy and ecology throughout their evolution. The Late Triassic Thecodontosaurus antiquus occupies a basal position within Sauropodomorpha, being a key taxon for documenting how those morphofunctional transitions occurred. Here, we redescribe the braincase osteology and reconstruct the neuroanatomy of Thecodontosaurus, based on computed tomography data. The braincase of Thecodontosaurus shares the presence of medial basioccipital components of the basal tubera and a U-shaped basioccipital–parabasisphenoid suture with other basal sauropodomorphs and shows a distinct combination of characters: a straight outline of the braincase floor, an undivided metotic foramen, an unossified gap, large floccular fossae, basipterygoid processes perpendicular to the cultriform process in lateral view and a rhomboid foramen magnum. We reinterpret these braincase features in the light of new discoveries in dinosaur anatomy. Our endocranial reconstruction reveals important aspects of the palaeobiology of Thecodontosaurus, supporting a bipedal stance and cursorial habits, with adaptations to retain a steady head and gaze while moving. -
Biological Sciences 1
Biological Sciences 1 Biological Sciences Marine Biology The Marine Biology major provides students with a strong foundation in basic biological concepts such as genetics, ecology, cell biology and marine systems as well as chemistry and mathematics. The plan of study provides the opportunity to choose elective courses from a wide variety of courses offered at Auburn University. In addition, students are required to take summer courses offered at marine labs around the United States, including Dauphin Island Sea Lab and Gulf Coast Research Lab. Students are also encouraged to consider internships and undergraduate research. Marine Biology graduates are well-prepared for advanced study in any marine science area or employment with marine labs, various governmental and nongovernmental agencies involved with coastal management and conservation, and tourism. Microbial, Cellular and Molecular Biology The Microbial, Cellular and Molecular Biology major provides students with an excellent foundation in the areas of microbiology, cellular and molecular biology that emphasizes the understanding of life at the cellular and molecular level. The choice of a formal option within the major allows students to concentrate on a particular area of interest. Each option provides a wide variety of courses and opportunities for undergraduate research. Students selecting the Microbiology option will be well prepared for postgraduate work or career advancement in a number of areas including food, environmental and medical microbiology. Students selecting the Cell and Molecular Biology option would also be well prepared for postgraduate study or career advancement in any area of eukaryotic cell or molecular biology. Both options provide excellent preparation for students interested in biotechnology or professional programs in the health sciences. -
Transformations of Lamarckism Vienna Series in Theoretical Biology Gerd B
Transformations of Lamarckism Vienna Series in Theoretical Biology Gerd B. M ü ller, G ü nter P. Wagner, and Werner Callebaut, editors The Evolution of Cognition , edited by Cecilia Heyes and Ludwig Huber, 2000 Origination of Organismal Form: Beyond the Gene in Development and Evolutionary Biology , edited by Gerd B. M ü ller and Stuart A. Newman, 2003 Environment, Development, and Evolution: Toward a Synthesis , edited by Brian K. Hall, Roy D. Pearson, and Gerd B. M ü ller, 2004 Evolution of Communication Systems: A Comparative Approach , edited by D. Kimbrough Oller and Ulrike Griebel, 2004 Modularity: Understanding the Development and Evolution of Natural Complex Systems , edited by Werner Callebaut and Diego Rasskin-Gutman, 2005 Compositional Evolution: The Impact of Sex, Symbiosis, and Modularity on the Gradualist Framework of Evolution , by Richard A. Watson, 2006 Biological Emergences: Evolution by Natural Experiment , by Robert G. B. Reid, 2007 Modeling Biology: Structure, Behaviors, Evolution , edited by Manfred D. Laubichler and Gerd B. M ü ller, 2007 Evolution of Communicative Flexibility: Complexity, Creativity, and Adaptability in Human and Animal Communication , edited by Kimbrough D. Oller and Ulrike Griebel, 2008 Functions in Biological and Artifi cial Worlds: Comparative Philosophical Perspectives , edited by Ulrich Krohs and Peter Kroes, 2009 Cognitive Biology: Evolutionary and Developmental Perspectives on Mind, Brain, and Behavior , edited by Luca Tommasi, Mary A. Peterson, and Lynn Nadel, 2009 Innovation in Cultural Systems: Contributions from Evolutionary Anthropology , edited by Michael J. O ’ Brien and Stephen J. Shennan, 2010 The Major Transitions in Evolution Revisited , edited by Brett Calcott and Kim Sterelny, 2011 Transformations of Lamarckism: From Subtle Fluids to Molecular Biology , edited by Snait B. -
The Origin and Early Evolution of Dinosaurs
Biol. Rev. (2010), 85, pp. 55–110. 55 doi:10.1111/j.1469-185X.2009.00094.x The origin and early evolution of dinosaurs Max C. Langer1∗,MartinD.Ezcurra2, Jonathas S. Bittencourt1 and Fernando E. Novas2,3 1Departamento de Biologia, FFCLRP, Universidade de S˜ao Paulo; Av. Bandeirantes 3900, Ribeir˜ao Preto-SP, Brazil 2Laboratorio de Anatomia Comparada y Evoluci´on de los Vertebrados, Museo Argentino de Ciencias Naturales ‘‘Bernardino Rivadavia’’, Avda. Angel Gallardo 470, Cdad. de Buenos Aires, Argentina 3CONICET (Consejo Nacional de Investigaciones Cient´ıficas y T´ecnicas); Avda. Rivadavia 1917 - Cdad. de Buenos Aires, Argentina (Received 28 November 2008; revised 09 July 2009; accepted 14 July 2009) ABSTRACT The oldest unequivocal records of Dinosauria were unearthed from Late Triassic rocks (approximately 230 Ma) accumulated over extensional rift basins in southwestern Pangea. The better known of these are Herrerasaurus ischigualastensis, Pisanosaurus mertii, Eoraptor lunensis,andPanphagia protos from the Ischigualasto Formation, Argentina, and Staurikosaurus pricei and Saturnalia tupiniquim from the Santa Maria Formation, Brazil. No uncontroversial dinosaur body fossils are known from older strata, but the Middle Triassic origin of the lineage may be inferred from both the footprint record and its sister-group relation to Ladinian basal dinosauromorphs. These include the typical Marasuchus lilloensis, more basal forms such as Lagerpeton and Dromomeron, as well as silesaurids: a possibly monophyletic group composed of Mid-Late Triassic forms that may represent immediate sister taxa to dinosaurs. The first phylogenetic definition to fit the current understanding of Dinosauria as a node-based taxon solely composed of mutually exclusive Saurischia and Ornithischia was given as ‘‘all descendants of the most recent common ancestor of birds and Triceratops’’. -
Massospondylus Carinatus Owen 1854 (Dinosauria: Sauropodomorpha) from the Lower Jurassic of South Africa: Proposed Conservation of Usage by Designation of a Neotype
Massospondylus carinatus Owen 1854 (Dinosauria: Sauropodomorpha) from the Lower Jurassic of South Africa: Proposed conservation of usage by designation of a neotype Adam M. Yates1* & Paul M. Barrett2 1Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Private Bag 3, WITS, 2050 Johannesburg, South Africa 2Department of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, U.K. Received 17 February 2010. Accepted 12 November 2010 The purpose of this article is to preserve the usage of the binomen Massospondylus carinatus by designating a neotype specimen. Massospondylus is the most abundant basal sauropodomorph dinosaur from the Early Jurassic strata of southern Africa. This taxon forms the basis for an extensive palaeobiological literature and is the eponym of Massospondylidae and the nominal taxon of a biostratigraphical unit in current usage, the ‘Massospondylus Range Zone’. The syntype series of M. carinatus (five disarticulated and broken vertebrae) was destroyed during World War II, but plaster casts and illustrations of the material survive. Nonetheless, these materials cannot act as type material for this taxon under the rules of the ICZN Code. In order to avoid nomenclatural instability, we hereby designate BP/1/4934 (a skull and largely complete postcranial skeleton) as the neotype of Massospondylus carinatus. Keywords: Dinosauria, Sauropodomorpha, Massospondylidae, Massospondylus, Massospondylus carinatus, neotype, South Africa, upper Elliot Formation, Early Jurassic. INTRODUCTION same taxon, possibly even the same individual, as at least Richard Owen described and named Massospondylus some of the syntype series of Massospondylus carinatus. carinatus (1854, p. 97) with carinatus as the type species of Their initial separation from Massospondylus carinatus the genus by monotypy. -
Implications for Predatory Dinosaur Macroecology and Ontogeny in Later Late Cretaceous Asiamerica
Canadian Journal of Earth Sciences Theropod Guild Structure and the Tyrannosaurid Niche Assimilation Hypothesis: Implications for Predatory Dinosaur Macroecology and Ontogeny in later Late Cretaceous Asiamerica Journal: Canadian Journal of Earth Sciences Manuscript ID cjes-2020-0174.R1 Manuscript Type: Article Date Submitted by the 04-Jan-2021 Author: Complete List of Authors: Holtz, Thomas; University of Maryland at College Park, Department of Geology; NationalDraft Museum of Natural History, Department of Geology Keyword: Dinosaur, Ontogeny, Theropod, Paleocology, Mesozoic, Tyrannosauridae Is the invited manuscript for consideration in a Special Tribute to Dale Russell Issue? : © The Author(s) or their Institution(s) Page 1 of 91 Canadian Journal of Earth Sciences 1 Theropod Guild Structure and the Tyrannosaurid Niche Assimilation Hypothesis: 2 Implications for Predatory Dinosaur Macroecology and Ontogeny in later Late Cretaceous 3 Asiamerica 4 5 6 Thomas R. Holtz, Jr. 7 8 Department of Geology, University of Maryland, College Park, MD 20742 USA 9 Department of Paleobiology, National Museum of Natural History, Washington, DC 20013 USA 10 Email address: [email protected] 11 ORCID: 0000-0002-2906-4900 Draft 12 13 Thomas R. Holtz, Jr. 14 Department of Geology 15 8000 Regents Drive 16 University of Maryland 17 College Park, MD 20742 18 USA 19 Phone: 1-301-405-4084 20 Fax: 1-301-314-9661 21 Email address: [email protected] 22 23 1 © The Author(s) or their Institution(s) Canadian Journal of Earth Sciences Page 2 of 91 24 ABSTRACT 25 Well-sampled dinosaur communities from the Jurassic through the early Late Cretaceous show 26 greater taxonomic diversity among larger (>50kg) theropod taxa than communities of the 27 Campano-Maastrichtian, particularly to those of eastern/central Asia and Laramidia. -
Appendix A. Supplementary Material
Appendix A. Supplementary material Comprehensive taxon sampling and vetted fossils help clarify the time tree of shorebirds (Aves, Charadriiformes) David Cernˇ y´ 1,* & Rossy Natale2 1Department of the Geophysical Sciences, University of Chicago, Chicago 60637, USA 2Department of Organismal Biology & Anatomy, University of Chicago, Chicago 60637, USA *Corresponding Author. Email: [email protected] Contents 1 Fossil Calibrations 2 1.1 Calibrations used . .2 1.2 Rejected calibrations . 22 2 Outgroup sequences 30 2.1 Neornithine outgroups . 33 2.2 Non-neornithine outgroups . 39 3 Supplementary Methods 72 4 Supplementary Figures and Tables 74 5 Image Credits 91 References 99 1 1 Fossil Calibrations 1.1 Calibrations used Calibration 1 Node calibrated. MRCA of Uria aalge and Uria lomvia. Fossil taxon. Uria lomvia (Linnaeus, 1758). Specimen. CASG 71892 (referred specimen; Olson, 2013), California Academy of Sciences, San Francisco, CA, USA. Lower bound. 2.58 Ma. Phylogenetic justification. As in Smith (2015). Age justification. The status of CASG 71892 as the oldest known record of either of the two spp. of Uria was recently confirmed by the review of Watanabe et al. (2016). The younger of the two marine transgressions at the Tolstoi Point corresponds to the Bigbendian transgression (Olson, 2013), which contains the Gauss-Matuyama magnetostratigraphic boundary (Kaufman and Brigham-Grette, 1993). Attempts to date this reversal have been recently reviewed by Ohno et al. (2012); Singer (2014), and Head (2019). In particular, Deino et al. (2006) were able to tightly bracket the age of the reversal using high-precision 40Ar/39Ar dating of two tuffs in normally and reversely magnetized lacustrine sediments from Kenya, obtaining a value of 2.589 ± 0.003 Ma. -
Postcranial Skeletal Pneumaticity in Sauropods and Its
Postcranial Pneumaticity in Dinosaurs and the Origin of the Avian Lung by Mathew John Wedel B.S. (University of Oklahoma) 1997 A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Integrative Biology in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Kevin Padian, Co-chair Professor William Clemens, Co-chair Professor Marvalee Wake Professor David Wake Professor John Gerhart Spring 2007 1 The dissertation of Mathew John Wedel is approved: Co-chair Date Co-chair Date Date Date Date University of California, Berkeley Spring 2007 2 Postcranial Pneumaticity in Dinosaurs and the Origin of the Avian Lung © 2007 by Mathew John Wedel 3 Abstract Postcranial Pneumaticity in Dinosaurs and the Origin of the Avian Lung by Mathew John Wedel Doctor of Philosophy in Integrative Biology University of California, Berkeley Professor Kevin Padian, Co-chair Professor William Clemens, Co-chair Among extant vertebrates, postcranial skeletal pneumaticity is present only in birds. In birds, diverticula of the lungs and air sacs pneumatize specific regions of the postcranial skeleton. The relationships among pulmonary components and the regions of the skeleton that they pneumatize form the basis for inferences about the pulmonary anatomy of non-avian dinosaurs. Fossae, foramina and chambers in the postcranial skeletons of pterosaurs and saurischian dinosaurs are diagnostic for pneumaticity. In basal saurischians only the cervical skeleton is pneumatized. Pneumatization by cervical air sacs is the most consilient explanation for this pattern. In more derived sauropods and theropods pneumatization of the posterior dorsal, sacral, and caudal vertebrae indicates that abdominal air sacs were also present.