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They said "the epithet carboniferous is of obvious application to this series".Henry Shaler Williams (1891) proposed Pennine System as the name for the Carboniferous.The end-Frasnian extinction (the largest) about 375 million years ago.
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.
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.
writes of fine-grained greenish sandstones deposited in freshwater in which land plant fossils are well preserved.
"Among the most attractive of these" tree-fern once called Cyelopteris (Round-leaved Fern), re named Palasopteris Hibernicus (Primitive Irish Fern). It was the "monarch of the primeval forests" whose "graceful fronds bent over the clear waters of a lake".