DOCSLIB.ORG

Thermal Excursions in the Ocean at the Cretaceous-Tertiary Boundary (Northern Morocco): 6 So Record of Phosphatic Fish Debris

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermal Excursions in the Ocean at the Cretaceous-Tertiary Boundary (Northern Morocco): 6 So Record of Phosphatic Fish Debris Palaeogeography, Palaeoclimatology, Palaeoecologv 105 (1993): 235-243 235 Elsevier Science Publishers B.V., Amsterdam Thermal excursions in the ocean at the Cretaceous-Tertiary boundary (northern Morocco): 6 sO record of phosphatic fish debris C. L6cuyer a, P. Grandjean b, J.R. O'Neil b, H. Cappetta c and F. Martineau a aLaboratoire de GOochimie Isotopique, GOosciences Rennes, UPR 4661 CNRS, UniversitO de Rennes I, 35042 Rennes codex, France hStable Isotope Laboratory, Department of Geological Sciences, University (~/Michigan, 1006 C.C. Little Building, Ann Arbor MI 48109-1063, USA ¢Laboratoire de PalOontologie, Place EugOne Bataillon, UniversitO de Montpellier H, 34060 Montpellier, France (Received November 24, 1992; revised and accepted May 27, 1993) ABSTRACT C. Lecuyer, P. Grandjean, J.R. O'Neil, H. Cappetta and F. Martineau, 1993. Thermal excursions in the ocean at the Cretaceous-Tertiary boundary (northern Morocco): c~lsO record of phosphatic fish debris. Palaeogeogr., Palaeoclimatol., Palaeoecol., 105: 235-243. High precision oxygen isotope analyses were made of phosphate extracted from 17 samples of nektonic and benthic fish debris sampled across the stratigraphic Cretaceous-Tertiary boundary in northern Morocco. A refinement of the silver phos- phate method was used to isolate phosphate from biogenic materials. Measured ~180 values of 18.6-20.5%o are interpreted as reflecting high-resolution thermal variations that affected the ocean water column of the western Tethys. The warm (27°C) water masses that characterized Maastrichtian times underwent rapid cooling and stabilized at an average temperature of 19°C during the Dano-Montian and Thanetian. This period of constant and cool temperature was followed by a relatively rapid but more gradual warming to about 25°C achieved in the Middle Ypresian. Significant small shifts in 6180 values between nektonic and benthic fauna recorded only during the stages of rapid warming or cooling may correspond to averaged thermal differences within the water column that developed in response to global climatic changes. The indicated temperature distribution could have been caused by thermal changes in the atmosphere rather than some signal carried by deep ocean currents. The oxygen isotope data coupled with previous measurements of REE and eNd~TIon the same samples support the suggestion that paleo-Pacific westward currents progressed as far as the northwestern part of the African platform at the end of the Cretaceous period. Introduction changes in the temperature of surface or bottom waters of the ocean can be examined in detail and There is increasing interest in the study of global possibly elucidated. The temperature may vary at changes and its effect on terrestrial and marine any location in the ocean as a result of (1) global environments. Most paleoclimatic information has warming or cooling, (2) changes in ocean circula- been derived from the study of exceptional features tion patterns as a result of Earth-scale climatic that are preserved in the geologic record and variations, or (3) changes in circulation patterns exposed in a geographically restricted area. as a result of regional tectonic events. Conclusions concerning climate can be drawn only One of the most spectacular examples of global if the area under examination is free of strong change occurred at the Cretaceous-Tertiary regional control. While the ultimate cause of global boundary, a time characterized by major faunal change is a matter of great debate, the role and extinctions and large-scale climatic variations importance of immediate second-order effects like (Alvarez et al., 1980; Shackleton, 1985; Officer 0031-0182/93/$06.00 ~ 1993 -- Elsevier Science Publishers B.V. All rights reserved. 236 C. LECUYER ET AL. et al., 1987; Keller, 1989). We have made measure- rounding shelves. Phosphate samples collected in ments of the oxygen isotope compositions of phos- northern Morocco and Israel, however, appear to phatic fish remains from the Cretaceous-Tertiary have recorded deep-water REE characteristics and section in northern Morocco in an attempt to were not subjected to regional controls. The geo- understand the causes of oceanic thermal varia- chemical data for these materials suggest that deep tions that may have occurred around this time cold water from the North Atlantic or other water period. The usefulness of oxygen isotope composi- from the eastern Tethys with a strong negative Ce tions of natural phosphates for paleothermometry anomaly and a eNd(T) value of ~ --5 flushed out has been well documented (e.g. Longinelli and shallow epicontinental seawater as early as the Nuti, 1973; Kolodny et al., 1983; Shemesh et al., Middle Cretaceous. 1983; Luz et al., 1984; Karhu and Epstein, 1986). In the present study we integrate the REE and Thus if well-preserved marine fish remains (teeth Nd isotope database with oxygen isotope analysis and bones) are available for analysis, it may be of the same phosphates and then address the possible to determine paleotemperatures of past following questions: (1) can thermal variations in oceans (Kolodny and Raab, 1988). In addition, the ancient water column be identified? (2) are REE contents and eNd values of such fish remains such thermal variations caused by introduction of provide an effective means of elucidating circula- an exotic deep water from the North Atlantic or tion patterns of ancient ocean water masses Tethys or rather by a global thermal change in the (Grandjean et al., 1987; 1988). atmosphere?, and (3) is there a regional climatic Shark and ray teeth from a section in northern correlation with the Eastern Tethys where samples Morocco were selected for this study because: (1) from Israel and Jordan have previously provided Northern Morocco was situated between the paleotemperatures for Cretaceous to Eocene Atlantic Ocean and the Tethys Sea in a region waters (Kolodny and Raab, 1988). where tectonic processes operative in the past are of great geologic interest and are relatively well- Analytical procedures understood through the time span under investiga- tion (Scotese et al., 1988; Bardossy and Dercourt, The Ag3PO 4 method 1990). (2) Splits of the same samples examined for REE contents and Nd isotope ratios by Grandjean Phosphatic oxygen in biogenic materials appears et al. (1988) were available for oxygen isotope to form in isotopic equilibrium with body fluids analysis. (3) The samples provide a very good time and, after the death of the animals, to be relatively resolution from Lower Maastrichtian to Upper resistant to oxygen isotope exchange with environ- Ypresian. (4) The combination of oxygen isotope mental fluids, especially during apatite recrystalli- data with the results of Grandjean et al. (1988) zation at the sediment-water interface (Luz and should provide a powerful geochemical tool to Kolodny, 1989). The first method of isolating the gain insight into the direction, amplitude and phosphate radical from fossil phosphatic materials origin of thermal variations of the oceans during for oxygen isotope analysis was published by this time interval. Tudge (1960) and modified successively by Grandjean et al. (1988) suggested that REE Longinelli (1965, 1966), Longinelli and Nuti contents and Nd isotope compositions of seawater (1973), Longinelli et al. (1976) and Kolodny et al. from continental shelves and platforms result (1983). This is a laborious method involving the largely from regionally controlled diagenetic fluxes. precipitation of a hygroscopic, low-temperature They proposed, furthermore, that the weak Ce form of BiPO4 after six days of wet chemistry. anomalies measured in modern phosphates are a The method presented here is a refinement of the reflection of the isolation of these materials from Ag3PO4 technique developed by Crowson et al. deep oceanic waters and that the Nd isotope (1992) and was selected because (1) the Ag3PO 4 compositions of phosphates are the same as those procedure is far less time-consuming than the of average labile sedimentary Nd from the sur- BiPO4 method, (2) measurements can be per- THE CRETACEOUS TERTIARY BOUNDARY (NORTHERN MOROCCO): 01~O RECORD OF PHOSPHATIC FISH DEBRIS 237 formed easily on natural samples as small as 15 mg regular addition of a few drops of DDW. The or less, (3) the Ag3PO4 crystals are stable and non- crystals are then collected on a millipore filter, hygroscopic, and (4) oxygen can be extracted washed three times with DDW and air dried at quantitatively from AgaPO 4 using BrF5 in a con- 60°C. The Ag3PO4 crystals produced this way are ventional silicate extraction line and the isotopic quite pure by the criterion that no contaminants measurements are reproducible with low standard were detected using either SEM or X-ray diffrac- deviations. tion analysis. After washing in distilled water, the samples are crushed in a stainless steel mortar and ground with Fluorination procedure and mass spectrometry an agate mortar and pestle. After dissolution of 15 30 mg of powdered sample in 2M HF at 2YC Aliquots of between 12 and 15 mg of Ag3PO 4 for 24 hours, the CaF 2 that precipitates is sepa- crystals are weighed into nickel reaction vessels rated from the phosphate solution by centrifu- and degassed 4 hours at room temperature and an gation. The CaF 2 precipitate is rinsed three times additional 4 hours at 150 200°C. This degassing using double deionized water (DDW) and the rinse procedure assures that atmospheric water is effi- water added to the phosphate solution which is ciently desorbed from the samples. A 5/1 mole finally neutralized with a 2M KOH solution. excess of BrF5 is reacted with the samples at 600°C Before use, the AmberliteTM-IRA-400(OH) ion for 12 hours. Chemical yields of near 100% were exchange resin is flushed with several liters of obtained routinely at the University of Michigan DDW to eliminate chloride and avoid precipitation and replicate analyses at the University of Rennes of AgC1. A 2-ml aliquot of cleaned resin is then (n= 25) of the NBS 120c Florida phosphate added along with the neutralized solution to a standard were very reproducible at a 6180 value polypropylene tube.
Load more

Recommended publications
  • OFR21 a Guide to Fossil Sharks, Skates, and Rays from The
    STATE OF DELAWARE UNIVERSITY OF DELAWARE DELAWARE GEOLOGICAL SURVEY OPEN FILE REPORT No. 21 A GUIDE TO FOSSIL SHARKS J SKATES J AND RAYS FROM THE CHESAPEAKE ANU DELAWARE CANAL AREA) DELAWARE BY EDWARD M. LAUGINIGER AND EUGENE F. HARTSTEIN NEWARK) DELAWARE MAY 1983 Reprinted 6-95 FOREWORD The authors of this paper are serious avocational students of paleontology. We are pleased to present their work on vertebrate fossils found in Delaware, a subject that has not before been adequately investigated. Edward M. Lauginiger of Wilmington, Delaware teaches biology at Academy Park High School in Sharon Hill, Pennsyl­ vania. He is especially interested in fossils from the Cretaceous. Eugene F. Hartstein, also of Wilmington, is a chemical engineer with a particular interest in echinoderm and vertebrate fossils. Their combined efforts on this study total 13 years. They have pursued the subject in New Jersey, Maryland, and Texas as well as in Delaware. Both authors are members of the Mid-America Paleontology Society, the Delaware Valley Paleontology Society, and the Delaware Mineralogical Society. We believe that Messrs. Lauginiger and Hartstein have made a significant technical contribution that will be of interest to both professional and amateur paleontologists. Robert R. Jordan State Geologist A GUIDE TO FOSSIL SHARKS, SKATES, AND RAYS FROM THE CHESAPEAKE AND DELAWARE CANAL AREA, DELAWARE Edward M. Lauginiger and Eugene F. Hartstein INTRODUCTION In recent years there has been a renewed interest by both amateur and professional paleontologists in the rich upper Cretaceous exposures along the Chesapeake and Delaware Canal, Delaware (Fig. 1). Large quantities of fossil material, mostly clams, oysters, and snails have been collected as a result of this activity.
    [Show full text]
  • Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism)
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1986 Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism). Barbara R. Standhardt Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Standhardt, Barbara R., "Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism)." (1986). LSU Historical Dissertations and Theses. 4209. https://digitalcommons.lsu.edu/gradschool_disstheses/4209 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a manuscript sent to us for publication and microfilming. While the most advanced technology has been used to pho­ tograph and reproduce this manuscript, the quality of the reproduction is heavily dependent upon the quality of the material submitted. Pages in any manuscript may have indistinct print. In all cases the best available copy has been filmed. The following explanation of techniques is provided to help clarify notations which may appear on this reproduction. 1. Manuscripts may not always be complete. When it is not possible to obtain missing pages, a note appears to indicate this. 2. When copyrighted materials are removed from the manuscript, a note ap­ pears to indicate this. 3.
    [Show full text]
  • Paleogene: Paleocene) Of
    Cainozoic Research, 8(1-2), pp. 13-28, December2011 Chondrichthyans from the Clayton Limestone Unit of the Midway Group (Paleogene: Paleocene) of Hot Spring County, Arkansas, USA ¹, ² Martin+A. Becker Lauren+C. Smith¹ & John+A. Chamberlain+Jr. 1 Department ofEnvironmentalScience, William Paterson University, Wayne, New Jersey 07470; e-mail: [email protected] 2 Department ofGeology, Brooklyn College andDoctoralProgram in Earth and EnvironmentalSciences, City University ofNew YorkGraduate Center, New York 10016; email:[email protected] Received 7 September 2010; revised version accepted 26 June 2011 LimestoneUnit of The Clayton the Midway Group (Paleocene) in southwestern Arkansas preserves one ofthe oldest chondrichthyan Cenozoic from the Gulf Coastal Plainofthe United assemblages yet reported States. Present are at least eight taxa, including; Odontaspis winkleriLeriche, Carcharias cf. whitei Carcharias Anomotodon 1905; (Arambourg, 1952); sp.; novus (Winkler, 1874); Cretalamnasp.; Otodus obliquus Agassiz, 1843; Hypolophodon sylvestris (White, 1931); Myliobatis dixoni Agassiz, 1843; and a chimaeridofindeterminate affiliation.Also present are lamnoid-type and carcharhinoid-type chondrichthyan vertebral centra. The Clayton chondrichthyan assem- blage derives from an outcrop locatedonly a few kilometersfrom a site exposing an assemblage ofMaastrichtianchondrichthyans from Because and the upper Arkadelphia Marl. these assemblages are closely spaced stratigraphically geographically, they provide data on chondrichthyan taxonomic turnover
    [Show full text]
  • Historical Biogeography of the Late Cretaceous Vertebrates of India: Comparison of Geophysical and Paleontological Data
    Khosla, A. and Lucas, S.G., eds., 2016, Cretaceous Period: Biotic Diversity and Biogeography. New Mexico Museum of Natural History and Science Bulletin 71. 317 HISTORICAL BIOGEOGRAPHY OF THE LATE CRETACEOUS VERTEBRATES OF INDIA: COMPARISON OF GEOPHYSICAL AND PALEONTOLOGICAL DATA OMKAR VERMA1, ASHU KHOSLA2, FRANCISCO J. GOIN3 AND JASDEEP KAUR2 1Geology Discipline Group, School of Sciences, Indira Gandhi National Open University, New Delhi – 110 068, India, e-mail: omkarverma@ ignou.ac.in; 2Department of Geology, Centre for Advanced Studies, Panjab University, Sector-14, Chandigarh – 160014, India, e-mail: [email protected], e-mail: [email protected]; 3Consejo Nacional de Investigaciones Científicas y Técnicas and División Paleontología Vertebrados, Museo de Ciencias Naturales de La Plata, B1900FWA La Plata, Argentina, e-mail: [email protected] Abstract—The Cretaceous was a special time for the Indian plate as it was separated from Gondwana landmasses and started its northward journey across the Tethys Sea towards the Equator. The northward movement of this plate implied shifting latitudes and climate belts, until it finally collided with Asia during the early Cenozoic. Geophysical data and plate tectonic models show that after splitting from Gondwana, the Indian plate remained as an isolated continent for more than 45 Ma during the Cretaceous; thus, it predicts a remarkable biotic endemism for the continent. Paleontological data on the Cretaceous vertebrates of India is best known for Maastrichtian time; in turn, the pre-Maastrichtian record is very poor—it contains very few fossils of fishes and marine reptiles. The Maastrichtian fossil record comprises vertebrates of Gondwana and Laurasian affinities and some endemic, ancient lineages as well.
    [Show full text]
  • Family-Group Names of Fossil Fishes
    European Journal of Taxonomy 466: 1–167 ISSN 2118-9773 https://doi.org/10.5852/ejt.2018.466 www.europeanjournaloftaxonomy.eu 2018 · Van der Laan R. This work is licensed under a Creative Commons Attribution 3.0 License. Monograph urn:lsid:zoobank.org:pub:1F74D019-D13C-426F-835A-24A9A1126C55 Family-group names of fossil fishes Richard VAN DER LAAN Grasmeent 80, 1357JJ Almere, The Netherlands. Email: [email protected] urn:lsid:zoobank.org:author:55EA63EE-63FD-49E6-A216-A6D2BEB91B82 Abstract. The family-group names of animals (superfamily, family, subfamily, supertribe, tribe and subtribe) are regulated by the International Code of Zoological Nomenclature. Particularly, the family names are very important, because they are among the most widely used of all technical animal names. A uniform name and spelling are essential for the location of information. To facilitate this, a list of family- group names for fossil fishes has been compiled. I use the concept ‘Fishes’ in the usual sense, i.e., starting with the Agnatha up to the †Osteolepidiformes. All the family-group names proposed for fossil fishes found to date are listed, together with their author(s) and year of publication. The main goal of the list is to contribute to the usage of the correct family-group names for fossil fishes with a uniform spelling and to list the author(s) and date of those names. No valid family-group name description could be located for the following family-group names currently in usage: †Brindabellaspidae, †Diabolepididae, †Dorsetichthyidae, †Erichalcidae, †Holodipteridae, †Kentuckiidae, †Lepidaspididae, †Loganelliidae and †Pituriaspididae. Keywords. Nomenclature, ICZN, Vertebrata, Agnatha, Gnathostomata.
    [Show full text]
  • (Paleocene) Near Malvern, Arkansas, USA, with Comments on the K/Pg Boundary
    Chondrichthyans from the Lower Clayton Limestone Unit of the Midway Group (Paleocene) near Malvern, Arkansas, USA, with comments on the K/Pg boundary Harry M. Maisch, Martin A. Becker & Michael L. Griffiths PalZ Paläontologische Zeitschrift ISSN 0031-0220 PalZ DOI 10.1007/s12542-019-00494-7 1 23 Your article is protected by copyright and all rights are held exclusively by Paläontologische Gesellschaft. This e-offprint is for personal use only and shall not be self- archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. 1 23 Author's personal copy PalZ https://doi.org/10.1007/s12542-019-00494-7 RESEARCH PAPER Chondrichthyans from the Lower Clayton Limestone Unit of the Midway Group (Paleocene) near Malvern, Arkansas, USA, with comments on the K/Pg boundary Harry M. Maisch IV1 · Martin A. Becker1 · Michael L. Grifths1 Received: 13 March 2019 / Accepted: 17 September 2019 © Paläontologische Gesellschaft 2019 Abstract The Lower Clayton Limestone Unit (LCLU) of the Midway Group (Paleocene) near Malvern, Arkansas, USA contains an assemblage of chondrichthyans recently exposed by excavation for highway stabilization. Chondrichthyan teeth in this assem- blage belong to at least 12 taxa including: Ginglymostoma subafricanum, Carcharias cf.
    [Show full text]
  • Late Cretaceous (Maastrichtian) Chondrichthyes and Osteichthyes from Northeastern Iberia
    Palaeogeography, Palaeoclimatology, Palaeoecology 465 (2017) 278–294 Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo Late Cretaceous (Maastrichtian) Chondrichthyes and Osteichthyes from northeastern Iberia Alejandro Blanco a,⁎,MártonSzabób,c, Àngel Blanco-Lapaz d, Josep Marmi a a Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, C/Escola Industrial 23, 08201 Sabadell, Cataluña, Spain b Hungarian Natural History Museum, Department of Paleontology and Geology, Ludovika tér 2, Budapest 1083, Hungary c MTA-ELTE Lendület Dinosaur Research Group, Pázmány Péter Sétány 1/C, Budapest 1117, Hungary d Institut für Naturwissenschaftliche Archäologie, Universität Tübingen, Rümelinstr. 23, 72070 Tübingen, Germany article info abstract Article history: Intensive sampling for vertebrate microfossils has yielded abundant fish remains in the Maastrichtian units of the Received 21 May 2016 Tremp Formation (southern Pyrenees, Catalonia, Spain). Samples were taken from eight new sites representing Received in revised form 24 October 2016 different palaeoenvironments including coastal wetlands and floodplains, in order to assess the fish diversity and Accepted 25 October 2016 to gain a better understanding of the last dinosaur-dominated ecosystems of northeastern Spain. The results sug- Available online 5 November 2016 gest that a diverse ichthyofauna inhabited these transitional to inland fluvial settings throughout the Maastrichtian, comprising both marine and freshwater taxa. Three different chondrichthyans, eight basal Keywords: Lepisosteiformes neopterygians and at least seven teleostean species were found, the latter being more diverse than in other Phyllodontidae Maastrichtian localities in Europe. Fossil evidence from the studied late Maastrichtian assemblages suggests Osteoglossiformes that teleosteans were present in all the trophic guilds.
    [Show full text]
  • Proceedings of the Tenth Conference on Fossil Resources May 13-15, 2014 Rapid City, South Dakota
    PROCEEDINGS OF THE TENTH CONFERENCE ON FOSSIL RESOURCES May 13-15, 2014 Rapid City, South Dakota Edited by Vincent L. Santucci, Gregory A. Liggett, Barbara A. Beasley, H. Gregory McDonald and Justin Tweet Dakoterra Vol. 6 Eocene-Oligocene rocks in Badlands National Park, South Dakoata. Table of Contents Dedication ....................................................................................8 Introduction ..................................................................................9 Presentation Abstracts *Preserving THE PYGMY MAMMOTH: TWENTY YEARS OF collaboration BETWEEN CHANNEL ISLANDS National PARK AND THE MAMMOTH SITE OF HOT SPRINGS, S. D., INC. LARRY D. AGENBROAD, MONICA M. BUGBEE, DON P. MORRIS and W. JUSTIN WILKINS .......................10 PERMITS AND PALEONTOLOGY ON BLM COLORADO: RESULTS FROM 2009 TO 2013 HARLEY J. ARMSTRONG .....................................................................................................................................10 DEVIL’S COULEE DINOSAUR EGG SITE AND THE WILLOW CREEK HOODOOS: HOW SITE VARIABLES INFLUENCE DECISIONS MADE REGARDING PUBLIC ACCESS AND USE AT TWO DESIGNATED PROVINCIAL HISTORIC SITES IN ALBERTA, CANADA JENNIFER M. BANCESCU ...................................................................................................................................12 USDA FOREST SERVICE PALEONTOLOGY PASSPORT IN TIME PROGRAM: COST EFFECTIVE WAY TO GET FEDERAL PALEONTOLOGY PROJECTS COMPLETED BARBARA A. BEASLEY and SALLY SHELTON ...................................................................................................17
    [Show full text]
  • Biodiversity and Extinction Patterns of Chondrichthyes from the Cretaceous-Paleogene Boundary, Central Texas
    BIODIVERSITY AND EXTINCTION PATTERNS OF CHONDRICHTHYES FROM THE CRETACEOUS-PALEOGENE BOUNDARY, CENTRAL TEXAS A Senior Scholars Thesis by TRACEY JANUS Submitted to the Office of Undergraduate Research Texas A&M University in partial fulfillment of the requirements for the designation as UNDERGRADUATE RESEARCH SCHOLAR April 2009 Major: Geology BIODIVERSITY AND EXTINCTION PATTERNS OF CHONDRICHTHYES FROM THE CRETACEOUS-PALEOGENE BOUNDARY, CENTRAL TEXAS A Senior Scholars Thesis by TRACEY JANUS Submitted to the Office of Undergraduate Research Texas A&M University in partial fulfillment of the requirements for the designation as UNDERGRADUATE RESEARCH SCHOLAR Texas A&M University Approved by: Research Advisor: Thomas Stidham Associate Dean for Undergraduate Research: Robert C. Webb April 2009 Major: Geology iii ABSTRACT Biodiversity and Extinction Patterns of Chondrichthyes from the Cretaceous-Paleogene Boundary, Central Texas. (April 2009) Tracey Janus Department of Geology and Geophysics Texas A&M University Research Advisor: Dr. Thomas Stidham Department of Biology The Cretaceous-Paleogene (KP) mass extinction is the second largest mass extinction in the history of the world with over 70% of known marine and terrestrial species suffering extinction in that event. One of the most well studied KP sections is located in the Brazos River in Falls/Milam County and has been extensively studied for its sedimentology, isotopic properties, and latest Cretaceous microfossils, but the vertebrate fauna has not been studied until now. The Brazos River sites are composed of hummocky cross-bedded sandstone beds with intercalated bone beds between the hummocks. I sorted hundreds of teeth from sharks, batoids, and bony fish, as well as thousands of bone fragments from the processed sediments.
    [Show full text]
  • Neoselachii Du Maastrichtien Au Sud Du Niger Marc Michaut
    Neoselachii du Maastrichtien au sud du Niger Marc Michaut To cite this version: Marc Michaut. Neoselachii du Maastrichtien au sud du Niger. 2018. hal-01729203 HAL Id: hal-01729203 https://hal.archives-ouvertes.fr/hal-01729203 Submitted on 12 Mar 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Neoselachii du Maastrichtien au sud du Niger Marc Michaut Institut préparatoire aux études scientifiques et techniques, Université de Tunis, La Marsa, Tunisie 10 mars 2018 Abstract Numerous and various remains of the Neoselachii can be found in the Nigerian sites of the Maastrichtian period. Nevertheless the fossils are scattered, never being connected each other. Five species among the seven ones presented here were already known ; yet we provide new elements and precisions about them. The two new species belong to Rhombodontidae, one of them looking like a recently described Spanish species but without identity. We also try to match the fossil items to other ones for each species ; however, this is not always clearly feasible. Coprolites are studied in the end of this article ; they are abundant and generally in good condition but it is a challenge to specify their perpetrators.
    [Show full text]
  • Depositional Model of a Late Cretaceous Dinosaur Fossil Concentration, Lance Formation Summer Rose Weeks
    Loma Linda University TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works Loma Linda University Electronic Theses, Dissertations & Projects 9-2016 Depositional Model of a Late Cretaceous Dinosaur Fossil Concentration, Lance Formation Summer Rose Weeks Follow this and additional works at: http://scholarsrepository.llu.edu/etd Part of the Geology Commons, and the Paleontology Commons Recommended Citation Weeks, Summer Rose, "Depositional Model of a Late Cretaceous Dinosaur Fossil Concentration, Lance Formation" (2016). Loma Linda University Electronic Theses, Dissertations & Projects. 405. http://scholarsrepository.llu.edu/etd/405 This Thesis is brought to you for free and open access by TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works. It has been accepted for inclusion in Loma Linda University Electronic Theses, Dissertations & Projects by an authorized administrator of TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works. For more information, please contact [email protected]. LOMA LINDA UNIVERSITY School of Medicine in conjunction with the Faculty of Graduate Studies ____________________ Depositional Model of a Late Cretaceous Dinosaur Fossil Concentration, Lance Formation by Summer Rose Weeks ____________________ A Thesis submitted in partial satisfaction of the requirements for the degree Masters of Science in Geology ____________________ September 2016 © 2016 Summer Rose Weeks All Rights Reserved Each person whose signature appears below certifies that this thesis in his/her opinion is adequate, in scope and quality, as a thesis for the degree Master of Science. , Chairperson Leonard Brand, Professor of Biology and Paleontology Arthur V. Chadwick, Professor of Biology, Southwestern Adventist University Kevin E. Nick, Associate Professor of Geology iii ACKNOWLEDGEMENTS Financial support for this research has come from Loma Linda University.
    [Show full text]
  • Vertebrate Microfossil Diversity from the Tremp Formation
    ADVERTIMENT. Lʼaccés als continguts dʼaquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials dʼinvestigació i docència en els termes establerts a lʼart. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix lʼautorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No sʼautoritza la seva reproducció o altres formes dʼexplotació efectuades amb finalitats de lucre ni la seva comunicació pública des dʼun lloc aliè al servei TDX. Tampoc sʼautoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs. ADVERTENCIA. El acceso a los contenidos de esta tesis doctoral y su utilización debe respetar los derechos de la persona autora. Puede ser utilizada para consulta o estudio personal, así como en actividades o materiales de investigación y docencia en los términos establecidos en el art. 32 del Texto Refundido de la Ley de Propiedad Intelectual (RDL 1/1996). Para otros usos se requiere la autorización previa y expresa de la persona autora. En cualquier caso, en la utilización de sus contenidos se deberá indicar de forma clara el nombre y apellidos de la persona autora y el título de la tesis doctoral.
    [Show full text]