starting about 2.500,000,000 years ago, sedimentary rocks affected by higher amounts of oxygen in the atmosphere, appear red, as though rusted. Fossils include earliest fish, but of types very different from modern ones. signs of the "tentative presence" of plants on land.Mesoproterozoic from 1,600,000,000 to 1,000,000,000 years ago. Particular importance attaches to occurred around 1,300,000,000 years ago during the late Mesoproterzoic era, after the earth's transition to a more highly oxygenated atmosphere with an ozone screen. Deposits that made Westmorland Green slate formed around 450 million years ago. About 50 million years later, the material was altered by heat and pressure (metamorphosed) to slate, during mountain-building. After many more millions of years, they resembled patches of moss a few centimeters high.
"More than 3.5 billion years ago, small single-celled organisms acquired the capacity to photosynthesize" "Plants were restricted to the aquatic world until three billion years later, the first uncontroversial evidence for life is found 2,700,000,000 years ago.
The reference relates to sulphate and iron reduction as early forms of microbial respiration.
The end-Frasnian extinction was most pronounced in tropical environments, particularly in the reefs of the shallow seas.
Reef building sponges called stromatoporoids and corals suffered losses and stromatoporoids finally disappeared in the third extinction near the end of the Devonian.
The amoeba has no hard part, but some single cell organisms produce microscopic skeletons or shells. Fossil evidence is consistent with these gene-based estimates. which, from a supposed resemblance.the blossom of a liliaceous plant have been denominated Encrinites". But things changed in the : There were no land animals and extinctions were confined to water life.
cells with nuclei certainly existed by 1,200,000,000 years ago. In 1835, William Kirby in On Power of God in Creation of Animals 2. There were two distinct extinctions roughly a million years apart.
) 13,800,000,000 (13.8 billion) years ago The creation of the universe according to present estimates of "big bang" - "Stephen Hawkings and others...
estimate between 18 and 11 billion with 13.8 being the closest estimation".
By carboniferous [carbon bearing] soils, Richard Kirwan in 1799 meant the "various sorts of earth or stone among or under which coal is usually found".
William Daniel Conybeare and William Phillips (1822, page vii) proposed to consider all rocks in an ascending order with a group including "not only the great coal-deposit itself, but those of the limestone and sandstone also on which it reposes" as the "medial" [middle] order.
All of the major animal groups of the Ordovician oceans survived, including trilobites, "When I view all beings not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Silurian system was deposited, they seem to me to become ennobled.