Jaws of extinction demo6/23/2023 ![]() Mass Extinction Second Mass Extinction: ~ 365 Million Years Ago (Late Devonian Extinction)Ī great number of ancient marine species rose and fell throughout this time. Glaciation of this magnitude locked up a large portion of the world’s water and significantly reduced sea levels, which deprived many species of their most essential habitats, destroyed food chains, and reduced reproductive success. The southern supercontinent Gondwana had a sudden beginning of mass glaciation near the end of the Ordovician period. First Mass Extinction: ~ 440 Million Years Ago (Ordovician-Silurian Extinction)Ĭorals and shelled brachiopods were abundant during the time of the first mass extinction on Earth, but they had not yet made it onto land. Archaeopteryx Fossil Mass ExtinctionĪs defined by scientists, mass extinction is when approximately three-quarters of all species disappear over a short period of geological time, which is less than 2.8 million years. This finding supported the theory that birds descended from reptiles. It had broad wings and feathers like birds. It also had jaws with teeth and a long bone tail like dinosaurs, as well as the skeletal elements of both. Evolutionary Gaps Archaeopteryx FossilĪ 150–145-million-year-old fossil of Archaeopteryx was discovered in southern Germany just two years after Darwin wrote On the Origin of Species. ![]() One of these gaps was bridged by small, bipedal dinosaurs and birds, which was one of the first. These so-called “gaps” or “missing links in the chain of evolution” are increasingly filled by transitional fossil specimens as we learn more about the evolution of certain species lines. The evidence also demonstrates that gaps in the fossil record that initially appeared to exist are actually the result of incomplete data collecting. Fossil Record Evolutionary Gaps Filled in the Fossil Record ![]() Their presence demonstrates that species are not stable and can change through time to become new species. Some ancient creatures possessed characteristics that crossed over into important groupings of organisms. This proof demonstrates the enormous variety of living things that have existed. Rock deposits provide an indisputable record of historical changes over very long time periods.
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