Fossils

Source: Wikipedia. Pages: 137. Chapters: Paleontology, Fossil, Punctuated equilibrium, Trilobite, Quantum evolution, Tetrapod, Index fossil, Acritarch, Ammonite, Crinoid, Coccolithophore, Machaerid, Anomalocaridid, Cambrian explosion, Ediacara biota, Labyrinthodontia, Small shelly fauna, Debate about Cambrian Lophotrochozoans, List of fossil sites, Bivalvia, Ammolite, Transitional fossil, Taxonomy of commonly fossilised invertebrates, Living fossil, Diatomaceous earth, Strathcona Fiord, Palynology, History of invertebrate paleozoology, List of adaptive radiated Hawaiian honeycreepers by form, Invertebrate paleontology, Micropaleontology, Lagerstätte, Petrified wood, Fossil collecting, LACM 149371, AL 333, Paleontological sites of Lebanon, Geologic record, List of U.S. state fossils, Discredited hypotheses for the Cambrian explosion, List of adaptive radiated marsupials by form, Biostratigraphy, Stegocephalia, Paleoleishmania, Petrocardium, Fossil embryo, Permineralization, Megabalanus, Phosphatic fossilization, Signor-Lipps effect, Biretia, Montrichardia aquatica, Beecher's Trilobite type preservation, Aacocrinus, Endocast, Fossils of Egypt, Fossil Cabin, Transfer technique, Hurdia, Ammonitina, Fossil trade, Allotrioceras, Submerged forest, Counter slab, Fern spike, Prehistoric insects, Francevillian Group Fossil, Palynofacies, Nummulite, Bone bed, Scolecodont, Macrofossil, Phyllospondyli, Black Hills Institute of Geological Research, Inc., Pygidium, Fossil collecting code, Petrifaction, Eozoon canadense, Plumulites canadensis, Banded tube, Compression fossil, Subfossil, List of fossils, Doritites bosniackii, Faunal assemblage, Cryptospores, Tricuspes, Ramonalinidae, Fossil park, Fossil wood, Calcimicrobe, Vendotaenid, Fossil Hash, Culoptila aguilerai, Heterastridium, Carbonaceous film, Heuweltjie, Derived fossil, Indian bead, Ichthyolith, Driftwood Canyon Provincial Park, Copaline, Carpolite, Lysvaella, Didymograptus. Excerpt: The Cambrian explosion or Cambrian radiation was the relatively rapid appearance, over a period of many million years, of most major Phyla around , as found in the fossil record. This was accompanied by a major diversification of other organisms, including animals, phytoplankton, and calcimicrobes. Before about , most organisms were simple, composed of individual cells occasionally organized into colonies. Over the following 70 or 80 million years the rate of evolution accelerated by an order of magnitude (as defined in terms of the extinction and origination rate of species) and the diversity of life began to resemble today's. The Cambrian explosion has generated extensive scientific debate. The seemingly rapid appearance of fossils in the "Primordial Strata" was noted as early as the mid 19th century, and Charles Darwin saw it as one of the main objections that could be made against his theory of evolution by natural selection. The long-running puzzlement about the appearance of the Cambrian fauna, seemingly abruptly and from nowhere, centers on three key points: whether there really was a mass diversification of complex organisms over a relatively short period of time during the early Cambrian; what might have caused such rapid change; and what it would imply about the origin and evolution of animals. Interpretation is difficult due to a limited supply of evidence, based mainly on an incomplete fossil record and chemical signatures left in Cambrian rocks. Geologists as long ago as William Buckland (1784-1856) ...