Growth, Duplication and Lateral Mutual Compressive Deformation of Akouemma hemisphaeria on the Seafloor of Okondja Basin at 2.2 Ga (Gabon)
| Autor: | Osamu Sasaki, Ambroise Edou-Minko, Simplice Marin Ndong Ondo, Richard Maire, Mathieu Moussavou, Guillaume Fleury, Tomohiko Sato, Shigenori Maruyama, Makaya Mvoubou, Michel Mbina Mounguengui, Benjamin Musavu Moussavou, Richard Ortega, Yusuke Sawaki, Anders Kaestner, Asuncion Carmona, Stéphane Roudeau |
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| Přispěvatelé: | Université des Sciences et Techniques de Masuku [Franceville, Gabon] (USTM), Passages, Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Pau et des Pays de l'Adour (UPPA)-Ministère de la Culture et de la Communication (MCC)-Université de Bordeaux (UB), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratory of Atmospheric Chemistry [Paul Scherrer Institute] (LAC), Paul Scherrer Institute (PSI), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB)-Ministère de la Culture et de la Communication (MCC)-Université de Pau et des Pays de l'Adour (UPPA)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Sciences et Technologies - Bordeaux 1 |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
geography geography.geographical_feature_category Fission 010604 marine biology & hydrobiology Structural basin Sedimentary basin 010502 geochemistry & geophysics 01 natural sciences Seafloor spreading [SHS]Humanities and Social Sciences Paleontology Compressive deformation Perpendicular Ovoid Elongation Geology ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences |
| Zdroj: | International Journal of Geosciences International Journal of Geosciences, Scientific Research 2017, 08 (09), pp.1172-1191. ⟨10.4236/ijg.2017.89067⟩ |
| ISSN: | 2156-8359 2156-8367 |
| DOI: | 10.4236/ijg.2017.89067⟩ |
| Popis: | A colony of macro-fossils Akouemma hemisphaeria has been described in the Paleoproterozoic sedimentary basin of Okondja, Gabon. These fossils are classified into two groups according to their spheroidal or elongated forms. The spheroidal shapes are similar, have a tripartite structure with two hemispheres and a median disc and gradually pass to the elongated forms. These elongated forms have a pronounced bipartite tendency to two “hemispheres” separated by a median surface, and often have several ovoid “pieces” attached. The elongated specimens show both lateral growth marks and signs of fission. Growth marks are characterized by unidirectional homogeneous side elongations and lateral bud-like protuberances. The signs of fission are marked by circular furrows perpendicular to the direction of elongation, called “constriction furrows” with varying depths depending on the degree of fission of the specimen and internal vertical “division planes”. All of these ovoid and elongated specimens have undergone significant initial deformations due mainly to mutual lateral compressions in tabular beds. The Akouemma hemisphaeria macro-organisms, which were primitive probably sessile organisms, lived on the seafloor. They provide the oldest known record of macro-organisms on Earth having vegetative growth and asexual reproduction by budding, lateral elongation and fission. Their mutual lateral deformations would result from their growth. |
| Databáze: | OpenAIRE |
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