- published: 22 Feb 2016
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The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 million years ago (mya), to the beginning of the Devonian Period, about 416.0 ± 2.8 mya (ICS, 2004). As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by several million years. The base of the Silurian is set at a major extinction event when 60% of marine species were wiped out. See Ordovician-Silurian extinction events.
A significant evolutionary milestone during the Silurian was the appearance of jawed and bony fish. Life also began to appear on land in the form of small, moss-like, vascular plants which grew beside lakes, streams, and coastlines. However, terrestrial life would not greatly diversify and impact the landscape until the Devonian.
The Silurian system was first identified by British geologist Sir Roderick Impey Murchison, who was examining fossil-bearing sedimentary rock strata in south Wales in the early 1830s. He named the sequences for a Celtic tribe of Wales, the Silures, following the convention his friend Adam Sedgwick had established for the Cambrian. In 1835 the two men presented a joint paper, under the title On the Silurian and Cambrian Systems, Exhibiting the Order in which the Older Sedimentary Strata Succeed each other in England and Wales, which was the germ of the modern geological time scale. As it was first identified, the "Silurian" series when traced farther afield quickly came to overlap Sedgwick's "Cambrian" sequence, however, provoking furious disagreements that ended the friendship. Charles Lapworth resolved the conflict by defining a new Ordovician system including the contested beds. An early alternative name for the Silurian was "Gotlandian" after the strata of the Baltic island of Gotland.
Well I can hardly stand the heightened state I'm in
Barely stay inside of my own skin
Can't believe the life I get to live
Can't conceive the joy I have to give
All because - because of You
Because You made me - made me new
I am not the frightened guy I've been
Barely stay inside of my own skin
Well I can hardly keep the pace and catch my breath
Barely tell my right foot from my left
Got a giant geyser in my heart
Blowin up but hopfully not apart
All because - because of You
Because You made me - chase the Truth
Not the timid guy I've always been
Barely stay inside of my own skin
Well I can see the dawn of brighter bold new days
See my troubles wilt and blow away
See us holdin' hands both black and white
See myself, attempting what is right
All because - because of You
Because You made me - wanna come through
Not the empty promise that I've been
Barely stay inside of my own skin
Jump, jump, jumpin' right out of
Jump, jumpin' out of my skin