The Mesozoic era
The history of the Earth has been divided into time intervals. These intervals have different lengths since they are distinguished from each other on the basis of the events that happened during that particular time in the Earth’s history. In this paper I shall focus on the Mesozoic Era.
The Mesozoic era can also be referred to as the “Middle Life” era. This era witnessed the diversification of life, where giant beasts roamed the earth’s surface. It is divided into three periods, the Triassic Era (252 to 201.3 million years ago), the Jurassic Era (201.3 to 145 million years ago) and the Cretaceous Era (145 to 66 million years ago) (Rafferty pg. 5)
The beginning of the Mesozoic era can be marked at the time of the Permian extinction. During this period marine life was wiped out by ninety-six percent while the terrestrial species that were on the planet being wiped out by seventy percent. Life bounced back slowly, this eventually leading to a diversified animal life.
Life on Earth
Reptiles as well as the first dinosaurs came to rise during the Triassic Era. The Jurassic Era ushered in the birds and the mammals. The Cretaceous witnessed the rise of the Triceratops and Pteranodon as the idolized dinosaurs of the time (Geological Time Scale, web)
Coniferous plants (those with seeds that bear cones) were already in existence although they bloomed during the Mesozoic Era. During this period there was a rich presence of plant life that sufficiently provided food. This facilitated the growth of giant herbivores like the Argentinosaurus.
Changes during the Mesozoic Era
Earth did not have ice caps during the Mesozoic period since it was warmer that the conditions today. The continents at this time were combined into a single land mass called Pangaea. Lack of an adequate coastline resulted in the continent being unable to control its interior temperature. In effect severe temperature swings were experienced, with most of the land being covered by deserts. Regions around the equator had stretches of tropical rainforests.
Most life was wiped out of the earth by the end Permian extinction. A big portion of amphibious as well as crocodilians that inhabited the tropics became extinct. A giant asteroid also crashed onto Earth forming an enormous crater at Chicxulub, in the Yucatan Peninsula (Lewy, pg. 6). Incomplete fossil records have made it a challenge to explain the exact cause of the extinctions as well as how fast they took place.
Some theories link the extinctions to be caused by volcanic eruptions that happened in the Siberian Traps. These are said to have brought about a carbon dioxide spike in the atmosphere. Temperatures of the sea surface are believed to have been increased by the eruptions, resulting to acidification of the ocean that killed marine life.
- “Geological Time Scale”. Hyperphysics.phy-astr.gsu.edu. N.p., 2017. Web. 23 Feb. 2017.
- Lewy, Zeev. “How The Deccan Volcanism And The Chicxulub Asteroid Impact Resulted In The Biological Crisis Ending The Mesozoic Era”. Journal of Geography, Environment and Earth Science International 3.1 (2015): 1-11. Web.
- Rafferty, John P. The Mesozoic Era. 1st Ed. New York: Britannica Educational Pub., 2011. Print.