DOCSLIB.ORG

Zirabagtaria Ovata N

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Zirabagtaria Ovata N Systematics Repository abbreviations are as follows: Institute of Geology Museum (IGM), Departmento de Paleontología, Instituto de Geología, Cuidad Universitaria, Delegacíon de Coyoacán, 04510, México, D. F.; Mount Holyoke College Paleontology Collection (MHC), Department of Geology and Geography, Mount Holyoke College, South Hadley, Massachusetts, USA. Systematic Paleontology Zirabagtaria n. gen. Diagnosis: A small solzid kimberellomorph with an ‘oval’ body shape (sensu Schwabe 2010). The holotype is 11 mm long and 7 mm wide. The anterior 3.5 mm consists of a largely smooth head region. The thorax shows a faint, slightly curved axial lobe and is covered by numerous epidermal papillae or weakly-mineralized sclerites that are in many cases elongated in a direction perpendicular to the main body axis. The dorsal surface of the organism posterior of the head region bears what appears to be a scleritome consisting of tiny rectangular tubercles or weakly mineralized sclerites. The remainder of the body lacks a dorsal keel but has a very faint, slightly curved low-relief axial lobe and is covered by numerous dorsal epidermal papillae or weakly mineralized sclerites that are in many cases elongated in a direction perpen- dicular to the main body axis. The papillae resemble tiny rectangular tubercles. Many of the papillae show transverse elongation, and are organized in longitudinal columns, especially in the axial part of the organism. There are approximately ten longitudinal columns of mostly transversely-elongated papillae in the axial lobe region, and roughly 8–10 irregular columns on either side of the axial lobe in the ‘pleural’ fields. This gives a rough maximum of up to 30 longitudinal rows of scler- ites. The ‘glabella’ region is covered in tiny circular papillae. © Springer International Publishing AG 2018 271 M.A.S. McMenamin, Deep Time Analysis, Springer Geology, https://doi.org/10.1007/978-3-319-74256-4 272 Systematics Zirabagtaria ovata n. gen. n. sp. M. A. S. McMenamin Figures 3.26, 3.27, 3.46 and 3.47 Holotype: IGM 4995. Diagnosis. As for genus. Material: One specimen. Discussion: The dorsal surface of the organism posterior of the head region bears what appears to be a scleritome consisting of tiny rectangular tubercles or weakly mineralized sclerites. The array is somewhat similar to the tubercles described by Ivantsov (2007, his Pl. 2, Figs. 1–3) of Lossinia lissetskii, although unlike Lossinia, tubercles on the cephalic region of the solzid are sparse and the scleritome is mostly restricted to the post-cranial region. Zirabagtaria differs from Kimberella by lack- ing a “scalloped margin to the dorsal covering” (Ivantsov 2017). The papillae/sclerites were preserved by a thin parting of clay that settled on the dorsal surface of the Zirabagtaria before it was buried in sand. The presumably aragonitic sclerites (if they were mineralized at all) were subsequently dissolved out and replaced by the same siliceous cement that lithified the sandstone. Interestingly, a lopsided cephalic region, reminiscent of and perhaps homolo- gous (McMenamin 2003) to the effaced cephalon of an agraulid trilobite (McMenamin 2004), is apparent on both Lossinia lissetskii Ivantsov (2007, his Pl. 2, Fig. 3) and Zirabagtaria ovata n. gen. n. sp. (Figs. 3.26 and 3.27). A similar mor- phology of lopsided cephalic area is seen in the nektaspid trilobite-like Ediacaran Keretsa brutoni Ivantsov 2017 from the Arkhangelsk region of the Winter Coast, White Sea, Zimnie Gory, Russia. The papillate scleritome of Zirabagtaria ovata n. gen. n. sp. shows clear evi- dence for strong influence by a morphogenetic field in accordance with the Second Law of Morphogenetic Evolution. This evidence is twofold. First, the individual papillae are in many cases elongated in a transverse direction, and thus appear to be following the latitudinal field lines of the toroidal metazoan morphogenetic field. Second, the sclerites themselves are largely organized into longitudinal columns, and thus track the longitudinal field lines. The papillae at the posterior tip of Zirabagtaria ovata n. gen. n. sp. are of approximately the same size as the rest of the sclerites that constitute the scleritome. This suggests that the Zirabagtaria anus is not directly at the posterior tip of the animal, otherwise the posteriormost sclerites would presumably diminish in size as the longitudinal field lines converge at the posterior pole of the torus. This is precisely the position of the cloaca in solenogas- tres, and quite possibly Zirabagtaria had a similar morphology. Locality: Field sample 6 of 3/16/95; GPS coordinates of site are N30°24.041′, W111°57.141′ (average of seven measurements), altitude 526 m (average of six measurements). The fossil occurrence is approximately 5–10 m below the Clemente oolite, in unit 4 of the Clemente Formation. Palankiras n. gen. Diagnosis: A praecambridiid bilateralomorph (approximately 18 mm long and 11 mm wide) with a wide cephalic region, narrow body and ‘Y’ shaped posterior region. A prominent and well preserved anterior axial lobe (‘glabella’; Figs. 3.29 Systematics 273 and 3.30) occupies the anterior part of the cephalic region. A long genal spine arches downward almost to the transverse midline of the organism (Fig. 3.29). A linear depression at the proximal-posterior edge of the genal spine is interpreted here as a rudimentary facial suture. The posterior of the trunk of the creature is split into two slightly flared projections. Six faint tubercles occur along the midline of the trunk or thorax region; the anteriormost of these is largest. Palankiras palmeri n. gen. n. sp. M. A. S. McMenamin Figures 3.28, 3.29, 3.30 and 3.31 Holotype: IGM 4997. Diagnosis. As for genus. Material: One specimen. Discussion: The specimen is preserved as a convex epirelief. The incomplete nature of the fossil suggests the possibility that it represents a shed molt, which if so would make it the oldest known such structure in the fossil record. No appendages are preserved on the holotype. It is possible, however, that appendages did occur on either side of the narrow middle thoracic region of Palankiras palmeri n. gen. n. sp. An illustration of Praecambridium in Glaessner and Wade (1971, their Figure 1C) shows certain similarities to Palankiras as shown in Figs. 3.28, 3.29, 3.30 and 3.31, particularly as regards the first ‘metamere’ or isomere partition that in both Praecambridium sigillum and Palankiras palmeri n. gen. n. sp. is drawn out into an arching spine or spine-like structure. Several key features link Palankiras to both Praecambridium and trilobites. These are: presence of a genal spine, presence of a prominent axial lobe (glabella), and rudimentary facial sutures. The genal spine is clearly visible in Figs. 3.28 and 3.29. A linear depression at the proximal-posterior edge of the genal spine is inter- preted here as a rudimentary facial suture. This interpretation strongly supports the concept that Palankiras and Spriggina were both ecdysozoans that were required to molt. The prominent ovoid-spherical anterior lobe in the new praecambridiid is very reminiscent of the anterior lobe in Praecambridium sigillum as reconstructed by Glaessner and Wade (1971, their Fig. 3). The overall body form of Palankiras palmeri n. gen. n. sp. (Fig. 3.31) is intrigu- ing. Several trilobite orders have produced strange looking forms with what has been called a ‘classic fish skeleton’ appearance: large spherical glabella (“eye of fish”), long curved genal spines (“skull of fish”), separated pleural segments (“fish ribs”) and two prominent spines of the pygidium (“fish tail”). These trilobites include the Silurian cheirurid Deiphon forbesi (Fig. 3.32) and the Devonian giant lichid trilobite (>60 cm long) Terataspis grandis. Complete specimens of Terataspis grandis are unknown but the overall body shape of the trilobite may be accurately inferred from isolated pieces. The similar and odd body form of Deiphon and Terataspis, which by the way are not closely related trilobites, strongly suggests that their joint similarity to Palankiras palmeri n. gen. n. sp. is a result of an evolutionary atavism. Palankiras palmeri n. gen. n. sp. shares the entire “fish skeleton” outline, lacking only the ‘ribs’ (separated pleural segments). Curiously, this “fish skeleton” 274 Systematics trilobite form is currently unknown from Cambrian strata. The evolutionarily-­ convergent atavisms thus appear to be post-Cambrian Explosion phenomena. Locality: Field sample 6 of 3/16/95; GPS coordinates of site are N30°24.041′, W111°57.141′ (average of seven measurements), altitude 526 m (average of six measurements). The fossil occurrence is approximately 5–10 m below the Clemente oolite, in unit 4 of the Clemente Formation. Vendamonia n. gen. Diagnosis: A praecambridiid bilateralomorph (23 mm wide and 21 mm long) with three pairs of parapodia-like structures, a small anterior lobe (‘glabella’), and very wide, straight posterior margin that does not taper to form a pygidium or other ‘tail’ structure. The organism consists of a bar-shaped structure (the parapodial compo- nent of the great cirri or cirri base; Meyer 1926), a domal anterior axial lobe (buccal cavity), and two metamers (neuropodial or parapodial pairs) posterior to the anterior axial lobe (Fig. 3.34) A bifurcate distal appendage extends from the left parapodium of the first postcephalic pair. Vendamonia truncata n. gen. n. sp. M. A. S. McMenamin Figures 3.33, 3.34, 3.35 and 3.36 Holotype: IGM 4996. Diagnosis. As for genus. Material: Two specimens. Discussion: The specimen is preserved as a convex epirelief. In addition to the holo- type, a second specimen of Vendamonia truncata n. gen. n. sp., an apparent juvenile, was discovered in June 2017 (Figs. 3.35 and 3.36). This fossil is 4.3 mm in width and 5 mm in length. The original specimen creature was originally identified as the anterior portion of a Tomopteris-like worm, with the posterior of the animal excised to form a straight posterior margin.
Load more

Recommended publications
  • Sauropareion Anoplus, with a Discussion of Possible Life History
    The postcranial skeleton of the Early Triassic parareptile Sauropareion anoplus, with a discussion of possible life history MARK J. MACDOUGALL, SEAN P. MODESTO, and JENNIFER BOTHA−BRINK MacDougall, M.J., Modesto, S.P., and Botha−Brink, J. 2013. The postcranial skeleton of the Early Triassic parareptile Sauropareion anoplus, with a discussion of possible life history. Acta Palaeontologica Polonica 58 (4): 737–749. The skeletal anatomy of the Early Triassic (Induan) procolophonid reptile Sauropareion anoplus is described on the basis of three partial skeletons from Vangfontein, Middelburg District, South Africa. Together these three specimens preserve the large majority of the pectoral and pelvic girdles, articulated forelimbs and hindlimbs, and all but the caudal portion of the vertebral column, elements hitherto undescribed. Our phylogenetic analysis of the Procolophonoidea is consonant with previous work, positing S. anoplus as the sister taxon to a clade composed of all other procolophonids exclusive of Coletta seca. Previous studies have suggested that procolophonids were burrowers, and this seems to have been the case for S. anoplus, based on comparisons with characteristic skeletal anatomy of living digging animals, such as the presence of a spade−shaped skull, robust phalanges, and large unguals. Key words: Parareptilia, Procolophonidae, phylogenetic analysis, burrowing, Induan, Triassic, South Africa. Mark J. MacDougall [[email protected]], Department of Biology, Cape Breton University, Sydney, Nova Scotia, B1P 6L2, Canada and Department of Biology, University of Toronto at Mississauga, 3359 Mississauga Road, Ontario, L5L 1C6, Canada; Sean P. Modesto [[email protected]], Department of Biology, Cape Breton University, Sydney, Nova Scotia, B1P 6L2, Canada; Jennifer Botha−Brink [[email protected]], Karoo Palaeontology, National Museum, P.O.
    [Show full text]
  • Cambrian Cephalopods
    BULLETIN 40 Cambrian Cephalopods BY ROUSSEAU H. FLOWER 1954 STATE BUREAU OF MINES AND MINERAL RESOURCES NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY CAMPUS STATION SOCORRO, NEW MEXICO NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY E. J. Workman, President STATE BUREAU OF MINES AND MINERAL RESOURCES Eugene Callaghan, Director THE REGENTS MEMBERS Ex OFFICIO The Honorable Edwin L. Mechem ...................... Governor of New Mexico Tom Wiley ......................................... Superintendent of Public Instruction APPOINTED MEMBERS Robert W. Botts ...................................................................... Albuquerque Holm 0. Bursum, Jr. ....................................................................... Socorro Thomas M. Cramer ........................................................................ Carlsbad Frank C. DiLuzio ..................................................................... Los Alamos A. A. Kemnitz ................................................................................... Hobbs Contents Page ABSTRACT ...................................................................................................... 1 FOREWORD ................................................................................................... 2 ACKNOWLEDGMENTS ............................................................................. 3 PREVIOUS REPORTS OF CAMBRIAN CEPHALOPODS ................ 4 ADEQUATELY KNOWN CAMBRIAN CEPHALOPODS, with a revision of the Plectronoceratidae ..........................................................7
    [Show full text]
  • Aberrant Colourations in Wild Snakes: Case Study in Neotropical Taxa and a Review of Terminology
    SALAMANDRA 57(1): 124–138 Claudio Borteiro et al. SALAMANDRA 15 February 2021 ISSN 0036–3375 German Journal of Herpetology Aberrant colourations in wild snakes: case study in Neotropical taxa and a review of terminology Claudio Borteiro1, Arthur Diesel Abegg2,3, Fabrício Hirouki Oda4, Darío Cardozo5, Francisco Kolenc1, Ignacio Etchandy6, Irasema Bisaiz6, Carlos Prigioni1 & Diego Baldo5 1) Sección Herpetología, Museo Nacional de Historia Natural, Miguelete 1825, Montevideo 11800, Uruguay 2) Instituto Butantan, Laboratório Especial de Coleções Zoológicas, Avenida Vital Brasil, 1500, Butantã, CEP 05503-900 São Paulo, SP, Brazil 3) Universidade de São Paulo, Instituto de Biociências, Departamento de Zoologia, Programa de Pós-Graduação em Zoologia, Travessa 14, Rua do Matão, 321, Cidade Universitária, 05508-090, São Paulo, SP, Brazil 4) Universidade Regional do Cariri, Departamento de Química Biológica, Programa de Pós-graduação em Bioprospecção Molecular, Rua Coronel Antônio Luiz 1161, Pimenta, Crato, Ceará 63105-000, CE, Brazil 5) Laboratorio de Genética Evolutiva, Instituto de Biología Subtropical (CONICET-UNaM), Facultad de Ciencias Exactas Químicas y Naturales, Universidad Nacional de Misiones, Felix de Azara 1552, CP 3300, Posadas, Misiones, Argentina 6) Alternatus Uruguay, Ruta 37, km 1.4, Piriápolis, Uruguay Corresponding author: Claudio Borteiro, e-mail: [email protected] Manuscript received: 2 April 2020 Accepted: 18 August 2020 by Arne Schulze Abstract. The criteria used by previous authors to define colour aberrancies of snakes, particularly albinism, are varied and terms have widely been used ambiguously. The aim of this work was to review genetically based aberrant colour morphs of wild Neotropical snakes and associated terminology. We compiled a total of 115 cases of conspicuous defective expressions of pigmentations in snakes, including melanin (black/brown colour), xanthins (yellow), and erythrins (red), which in- volved 47 species of Aniliidae, Boidae, Colubridae, Elapidae, Leptotyphlopidae, Typhlopidae, and Viperidae.
    [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 Reassessment of the Taxonomic Position of Mesosaurs, and a Surprising Phylogeny of Early Amniotes
    GENERAL COMMENTARY published: 03 December 2018 doi: 10.3389/feart.2018.00220 Response: Commentary: A Reassessment of the Taxonomic Position of Mesosaurs, and a Surprising Phylogeny of Early Amniotes Michel Laurin 1* and Graciela Piñeiro 2 1 CR2P (UMR 7207), CNRS/MNHN Sorbonne Université, “Centre de Recherches sur la Paléobiodiversité et les Paléoenvironnements”, Muséum National d’Histoire Naturelle, Paris, France, 2 Departamento de Paleontología, Facultad de Ciencias, Montevideo, Uruguay Keywords: Mesosauridae, Parareptilia, Synapsida, Sauropsida, Amniota, Paleozoic, temporal fenestration A Commentary on Commentary: A Reassessment of the Taxonomic Position of Mesosaurs, and a Surprising Phylogeny of Early Amniotes by MacDougall, M. J., Modesto, S. P., Brocklehurst, N., Verrière, A., Reisz, R. R., and Fröbisch, J. (2018). Front. Earth Sci. 6:99. doi: 10.3389/feart.2018.00099 INTRODUCTION Edited by: Corwin Sullivan, University of Alberta, Canada Mesosaurs, known from the Early Permian of southern Africa, Brazil, and Uruguay, are the oldest known amniotes with a primarily, though probably not strictly, aquatic lifestyle (Nuñez Demarco Reviewed by: et al., 2018). Despite having attracted the attention of several prominent scientists, such as Wegener Tiago Simoes, University of Alberta, Canada (1966), who used them to support his theory of continental drift, and the great anatomist and paleontologist von Huene (1941), who first suggested the presence of a lower temporal fenestra *Correspondence: Michel Laurin in Mesosaurus, several controversies still surround mesosaurs. One concerns the presence of the [email protected] lower temporal fenestra in mesosaurs, which we accept (Piñeiro et al., 2012a; Laurin and Piñeiro, 2017, p. 4), contrary to Modesto (1999, 2006) and MacDougall et al.
    [Show full text]
  • Lessons from the Fossil Record: the Ediacaran Radiation, the Cambrian Radiation, and the End-Permian Mass Extinction
    OUP CORRECTED PROOF – FINAL, 06/21/12, SPi CHAPTER 5 Lessons from the fossil record: the Ediacaran radiation, the Cambrian radiation, and the end-Permian mass extinction S tephen Q . D ornbos, M atthew E . C lapham, M argaret L . F raiser, and M arc L afl amme 5.1 Introduction and altering substrate consistency ( Thayer 1979 ; Seilacher and Pfl üger 1994 ). In addition, burrowing Ecologists studying modern communities and eco- organisms play a crucial role in modifying decom- systems are well aware of the relationship between position and enhancing nutrient cycling ( Solan et al. biodiversity and aspects of ecosystem functioning 2008 ). such as productivity (e.g. Tilman 1982 ; Rosenzweig Increased species richness often enhances ecosys- and Abramsky 1993 ; Mittelbach et al. 2001 ; Chase tem functioning, but a simple increase in diversity and Leibold 2002 ; Worm et al. 2002 ), but the pre- may not be the actual underlying driving mecha- dominant directionality of that relationship, nism; instead an increase in functional diversity, the whether biodiversity is a consequence of productiv- number of ecological roles present in a community, ity or vice versa, is a matter of debate ( Aarssen 1997 ; may be the proximal cause of enhanced functioning Tilman et al. 1997 ; Worm and Duffy 2003 ; van ( Tilman et al. 1997 ; Naeem 2002 ; Petchey and Gaston, Ruijven and Berendse 2005 ). Increased species rich- 2002 ). The relationship between species richness ness could result in increased productivity through (diversity) and functional diversity has important 1) interspecies facilitation and complementary implications for ecosystem functioning during resource use, 2) sampling effects such as a greater times of diversity loss, such as mass extinctions, chance of including a highly productive species in a because species with overlapping ecological roles diverse assemblage, or 3) a combination of biologi- can provide functional redundancy to maintain cal and stochastic factors ( Tilman et al.
    [Show full text]
  • Geobiological Events in the Ediacaran Period
    Geobiological Events in the Ediacaran Period Shuhai Xiao Department of Geosciences, Virginia Tech, Blacksburg, VA 24061, USA NSF; NASA; PRF; NSFC; Virginia Tech Geobiology Group; CAS; UNLV; UCR; ASU; UMD; Amherst; Subcommission of Neoproterozoic Stratigraphy; 1 Goals To review biological (e.g., acanthomorphic acritarchs; animals; rangeomorphs; biomineralizing animals), chemical (e.g., carbon and sulfur isotopes, oxygenation of deep oceans), and climatic (e.g., glaciations) events in the Ediacaran Period; To discuss integration and future directions in Ediacaran geobiology; 2 Knoll and Walter, 1992 • Acanthomorphic acritarchs in early and Ediacara fauna in late Ediacaran Period; • Strong carbon isotope variations; • Varanger-Laplandian glaciation; • What has happened since 1992? 3 Age Constraints: South China (538.2±1.5 Ma) 541 Ma Cambrian Dengying Ediacaran Sinian 551.1±0.7 Ma Doushantuo 632.5±0.5 Ma 635 Ma 635.2±0.6 Ma Nantuo (Tillite) 636 ± 5Ma Cryogenian Nanhuan 654 ± 4Ma Datangpo 663±4 Ma Neoproterozoic Neoproterozoic Jiangkou Group Banxi Group 725±10 Ma Tonian Qingbaikouan 1000 Ma • South China radiometric ages: Condon et al., 2005; Hoffmann et al., 2004; Zhou et al., 2004; Bowring et al., 2007; S. Zhang et al., 2008; Q. Zhang et al., 2008; • Additional ages from Nama Group (Namibia), Conception Group (Newfoundland), and Vendian (White Sea); 4 The Ediacaran Period Ediacara fossils Cambrian 545 Ma Nama assemblage 555 Ma White Sea assemblage 565 Ma Avalon assemblage 575 Ma 585 Ma Doushantuo biota 595 Ma 605 Ma Ediacaran Period 615 Ma
    [Show full text]
  • Application of Geophysical and Geochronological Methods to Sedimentologic and Stratigraphic Problems in the Lower Cambrian Monkt
    University of Vermont ScholarWorks @ UVM Graduate College Dissertations and Theses Dissertations and Theses 2018 Application Of Geophysical And Geochronological Methods To Sedimentologic And Stratigraphic Problems In The Lower Cambrian Monkton Formation: Northwestern Vermont Henry C. Maguire University of Vermont Follow this and additional works at: https://scholarworks.uvm.edu/graddis Part of the Geology Commons Recommended Citation Maguire, Henry C., "Application Of Geophysical And Geochronological Methods To Sedimentologic And Stratigraphic Problems In The Lower Cambrian Monkton Formation: Northwestern Vermont" (2018). Graduate College Dissertations and Theses. 938. https://scholarworks.uvm.edu/graddis/938 This Thesis is brought to you for free and open access by the Dissertations and Theses at ScholarWorks @ UVM. It has been accepted for inclusion in Graduate College Dissertations and Theses by an authorized administrator of ScholarWorks @ UVM. For more information, please contact [email protected]. APPLICATION OF GEOPHYSICAL AND GEOCHRONOLOGICAL METHODS TO SEDIMENTOLOGIC AND STRATIGRAPHIC PROBLEMS IN THE LOWER CAMBRIAN MONKTON FORMATION: NORTHWESTERN VERMONT A Thesis Presented by Henry C. Maguire IV to The Faculty of the Graduate College of The University of Vermont In Partial Fulfillment of the Requirements for the Degree of Master of Science Specializing in Geology October, 2018 Defense Date: June 15, 2018 Thesis Examination Committee: Charlotte J. Mehrtens, Ph.D., Advisor Britt A. Holmén, Ph.D., Chairperson Laura E. Webb, Ph.D. Jon Kim, Ph.D. Cynthia J. Forehand, Ph.D., Dean of the Graduate College ABSTRACT The Monkton Formation of the western shelf stratigraphic sequence in Vermont (VT) is identified as a Lower Cambrian regressive sandstone unit containing parasequences recording tidal flat progradation.
    [Show full text]
  • 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 ------ - --- - - - - - --- --- - -- --- - -- - - ---
    [Show full text]
  • A Procolophonid (Parareptilia) from the Owl Rock Member, Chinle Formation of Utah, Usa
    Palaeontologia Electronica http://palaeo-electronica.org A PROCOLOPHONID (PARAREPTILIA) FROM THE OWL ROCK MEMBER, CHINLE FORMATION OF UTAH, USA Nicholas C. Fraser, Randall B. Irmis*, and David K. Elliott ABSTRACT An isolated skull of a procolophonid is described from the Owl Rock Member of the Chinle Formation in the Abajo Mountains of southeast Utah. Although poorly pre- served, this specimen exhibits features that demonstrate a phylogenetic relationship with leptopleuronine procolophonids. These include the dentition, the greatly expanded orbitotemporal opening, the prominent quadratojugal spikes, and the shape of the jugal. Nicholas C. Fraser. Virginia Museum of Natural History, Martinsville, Virginia 24112, USA. [email protected] Randall B. Irmis. Department of Geology, Northern Arizona University, Flagstaff, Arizona 86011, USA. *Current Address: University of California Museum of Paleontology, 1101 Valley Life Sciences Building, Berkeley, California 94720-4780. [email protected] David K. Elliott. Department of Geology, Northern Arizona University, Flagstaff, Arizona 86011, USA. [email protected] KEY WORDS: Procolophonidae; Parareptilia; Late Triassic; Chinle Formation PE Article Number: 8.1.13 Copyright: Society of Vertebrate Paleontology. May 2005 Submission: 28 June 2004. Acceptance: 6 March 2005. INTRODUCTION skull has been described in detail (Kemp 1974; Carroll and Lindsay 1985). The first member of the The Procolophonidae are a group of small clade to be named was Leptopleuron from the parareptiles (sensu Laurin and Reisz
    [Show full text]
  • Science Journals — AAAS
    RESEARCH EARLY ANIMALS years. For instance, hopanes are the hydrocarbon remains of bacterial hopanepolyols, whereas sat- urated steranes and aromatic steroids are diage- Ancient steroids establish netic products of eukaryotic sterols. The most common sterols of Eukarya possess a cholester- oid, ergosteroid, or stigmasteroid skeleton with the Ediacaran fossil Dickinsonia 27, 28, or 29 carbon atoms, respectively. These C27 to C29 sterols, distinguished by the alkylation as one of the earliest animals patternatpositionC-24inthesterolsidechain, function as membrane modifiers and are widely 1 1 2 3 distributed across extant Eukarya, but their rela- Ilya Bobrovskiy *, Janet M. Hope , Andrey Ivantsov , Benjamin J. Nettersheim , 3,4 1 tive abundances can give clues about the source Christian Hallmann , Jochen J. Brocks * organisms (24). Apart from Dickinsonia (Fig.1B),whichis The enigmatic Ediacara biota (571 million to 541 million years ago) represents the first one of the most recognizable Ediacaran fossils, macroscopic complex organisms in the geological record and may hold the key to our dickinsoniids include Andiva (Fig. 1C and fig. understanding of the origin of animals. Ediacaran macrofossils are as “strange as life on S1), Vendia, Yorgia, and other flattened Edia- another planet” and have evaded taxonomic classification, with interpretations ranging from caran organisms with segmented metameric marine animals or giant single-celled protists to terrestrial lichens. Here, we show that lipid bodies and a median line along the body axes, biomarkers extracted from organically preserved Ediacaran macrofossils unambiguously separating the “segments.” The specimens for clarify their phylogeny. Dickinsonia and its relatives solely produced cholesteroids, a Downloaded from this study were collected from two surfaces in hallmark of animals.
    [Show full text]
  • Retallack 2014 Newfoundland Ediacaran
    Downloaded from gsabulletin.gsapubs.org on May 2, 2014 Geological Society of America Bulletin Volcanosedimentary paleoenvironments of Ediacaran fossils in Newfoundland Gregory J. Retallack Geological Society of America Bulletin 2014;126, no. 5-6;619-638 doi: 10.1130/B30892.1 Email alerting services click www.gsapubs.org/cgi/alerts to receive free e-mail alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/ to subscribe to Geological Society of America Bulletin Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Notes © 2014 Geological Society of America Downloaded from gsabulletin.gsapubs.org on May 2, 2014 Volcanosedimentary paleoenvironments of Ediacaran fossils in Newfoundland Gregory J.
    [Show full text]