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Time Fossils and the Scientific Process Life through Time Evolutionary Milestones Extinctions Fossil Activities Fossils Glossary Further Research Link to Prehistoric Life |
 Life through TimeThis segment is an account of life in the Precambrian, the interval of time extending from the formation of the Earth 4,600 million years ago to the beginning of the Cambrian Period about 545 million years ago. During this interval, representing 88% of the Earth's history, life originated, primitive single-celled organisms evolved into more complex ones, and finally, almost at the end of the interval, the first multi-celled organisms appeared. None of the organisms present in the Precambrian had developed hard skeletons or shells that would be readily preserved as fossils, and consequently their fossil record is very sparse. Diversification of life in the oceans. This segment deals with the proliferation of life in the oceans during the Palaeozoic Era (545-251 million years ago), following the appearance of the first animals with hard shells at the beginning of the Cambrian Period. This segment deals with the migration of flora and fauna (both invertebrate and vertebrate) from the oceans into freshwater and terrestrial environments during the Middle Palaeozoic, and the subsequent diversification of biota. This segment deals with the fauna (both invertebrate and vertebrate) and flora from the Late Palaeozoic to the end of the Mesozoic, during which time the reptiles evolved from the anthracosaur amphibians during the Carboniferous Period, rose to dominance and then suffered massive extinctions. The rise of the modern fauna and flora. This element deals with the diversification of fauna and flora after the end-Cretaceous extinctions. This period of Earth history is characterised by the rise of birds and mammals and the establishment of the modern fauna and flora. |