Duration and Timing of The Extinction Events
Extinction rates appear to be higher than the background rate for an extended period lasting the last 20–25 million years of the Devonian. During this period, about eight to ten distinct events can be seen, of which two stand out as particularly severe. The Kellwasser event was preceded by a longer period of prolonged biodiversity loss. The fossil record of following first 15 million years of the Carboniferous is largely void of terrestrial animal fossils, likely related to losses during the end-Devonian Hangenberg event. This period is known as the Romer's gap.
Read more about this topic: Late Devonian Extinction
Famous quotes containing the words duration, timing, extinction and/or events:
“What matters it that man should have a little more knowledge of the universe? If he has it, he gets little higher. Is he not always infinitely removed from the end, and is not the duration of our life equally removed from eternity, even if it lasts ten years longer?”
—Blaise Pascal (1623–1662)
“Is it a new spring star
Within the timing chill,
Talking, or just a mime,
That rises in the blood
Thin Jack-and-Jilling seas
Without the human will?”
—Allen Tate (1899–1979)
“Man is an over-complicated organism. If he is doomed to extinction he will die out for want of simplicity.”
—Ezra Pound (1885–1972)
“Man is a stream whose source is hidden. Our being is descending into us from we know not whence. The most exact calculator has no prescience that somewhat incalculable may not balk the very next moment. I am constrained every moment to acknowledge a higher origin for events than the will I call mine.”
—Ralph Waldo Emerson (1803–1882)