Maureen Babuskow
3/10/2020
Assignment 7
1. Ordovician extinction:
- Happened around 443 million years ago. 85%of all species on earth went extinct.
Most likely a result of global cooling and reduced sea levels, which dramatically
impacted the many marine species living in warm, shallow coastal waters.
- An example of this would be marine animals.
2. Devonian Extinction:
- Happened 360 million years ago. Responsible for elimination of 70-80% of animal
species. Happened because of several stresses- such as excessive sedimentation,
rapid global warming or cooling, meteorites or comet impact, massive nutrient
runoff from continents.
- Example: wingless insects
3. Permo-Triassic:
- Happened 250 million years ago. The hypothesis is a massive volcanic eruption that
spewed more than 4 million cubic kilometers of lava. Eliminated 80-95% of species.
- Example: Lizards and turtles
4. End-Triassic:
- Happened 200 million years ago. Scientists contend that this event was caused by
climate change and rising sea levels resulting from sudden release if large amounts
of carbon dioxide.
- Example: invertebrates
5. Cretaceous-Paleogene:
- Happened 66 million years ago. Sudden mass extinction of three quarters of the
plant and animal species on earth. Caused most likely by a asteroid impact.
- Example: Dinosaurs
6. Current extinction:
- Caused mainly by human impact. Especially with the environment.
- Examples: deforestation & Global warming.
- Besides the other extinctions there is nothing we can do about it because it
happened millions of years ago but this current extinction there are some things
that we can do to help. One of the things would be needing to be very careful with
the environment, everything that we touch or do has some kind of impact of the
environment. We need to be careful with global warming, that seems to be one big
issue that is concerning in our environment right now.
Citations:
Holland, Steven M. “Ordovician-Silurian Extinction.” Encyclopædia Britannica, Encyclopædia
Britannica, Inc., 26 Nov. 2018, www.britannica.com/science/Ordovician-Silurian-extinction.
House, Michael R. “Devonian Extinctions.” Encyclopædia Britannica, Encyclopædia Britannica,
Inc., 27 Mar. 2017, www.britannica.com/science/Devonian-extinctions.
Chu, Jennifer. “End-Permian Extinction, Which Wiped out Most of Earth's Species, Was
Instantaneous in Geological Time.” Phys.org, Phys.org, 19 Sept. 2018, phys.org/news/2018-09end-permian-extinction-earth-species-instantaneous.html.
The Editors of Encyclopaedia Britannica. “End-Triassic Extinction.” Encyclopædia Britannica,
Encyclopædia Britannica, Inc., 6 Mar. 2019, www.britannica.com/science/end-Triassicextinction.
The Editors of Encyclopaedia Britannica. “K–T Extinction.” Encyclopædia Britannica,
Encyclopædia Britannica, Inc., 15 Apr. 2019, www.britannica.com/science/K-T-extinction.