Extinctions ON EARTH

ACCORDING TO MENTALFLOSS.COM]}... Five mass extinction events have wiped out nearly every living thing on this planet.  These extinctions are listed below...  and, number 6 which is unnumbered pertains to US and could happen as a result of GLOBAL WARMING...

1. ORDOVICIAN-SILURIAN EXTINCTION—445 MILLION YEARS AGO]}...  Most life forms were still living in the oceans at the time of the first mass extinction. There are many theories as to how that happened: global cooling that brought on an ice age, volcanic gases, or maybe changes in ocean chemistry. Whatever the cause, about 85 percent of species were wiped out.

2. LATE DEVONIAN EXTINCTION—375 MILLION YEARS AGO]}...  The oceans recovered and teemed with life once more, and that diversity had begun to spread onto land at the time of the second mass extinction, when 79–87 percent of all species died due to environmental change.
3. PERMIAN-TRIASSIC EXTINCTION—250 MILLION YEARS AGO]}...  This is also known as the Great Dying, and with good reason: 70 percent of land species and 90 percent of marine species disappeared, including half of all marine families. Plant life also suffered; only a few forests remained.
4. END-TRIASSIC EXTINCTION—200 MILLION YEARS AGO]}...  After the Great Dying, it took approximately 20 million years for the Earth to recover. Unfortunately, soon after the Earth returned to its previous level of diversity, 76 to 84 percent of all species died out.

5. END-CRETACEOUS MASS EXTINCTION—66 MILLION YEARS AGO]}...  This is the event we all know about. Many experts theorize that a large asteroid hit the Earth and contributed to rapid environmental changes. Sea levels plummeted, volcanic activity threw ash and poisonous gases into the air, and 71 to 81 percent of all species died.

HOLOCENE EXTINCTION—10,000 BCE to ONGOING]}...  This is us... Are we in the grip of the sixth mass extinction of life on our planet? It's unclear how many species we're losing annually—one widely cited estimate is 140,000 species per year