cretaceous mass extinction

Jacky Chen

April 26, 2023

Geol 1 Sec 80

Spring 2023

Work Count: 392

Cretaceous Mass Extinction

The Cretaceous mass extinction event is the most significant event that occurred in the world

after an asteroid fell. The mass extinction happened about 66 million years ago. This period was

marked by significant biodiversity, including marine species and dinosaurs, among other plant

species. This extinction rubbed out a significant percentage of biodiversity, although the earth

later recovered. Scientists have continually studied this event, with explanations such as the

asteroid impact theory attempting to explain what happened. This is a noteworthy occurrence in

scientific history, explaining how species went into extinction.

The cretaceous mass extinction was caused by several factors, including an asteroid impact

because these impacts produce a long cold winter that affects the potential global dinosaur

habitats (Chiarenza et al. 1). This is unlike the common belief that volcanic activity was

responsible for this extinction. This is because volcanism effectively supports the habitats

through long-term forcing that comes from volcanism, also explained through carbon

dioxide-induced warming results in habitat suitability, and thus the species would have been

better positioned to survive in such an environment. The asteroid impact theory of mass

extinctions asserts this evidence regarding the asteroids. The cretaceous extinction happened

after the asteroid hit the earth, causing debris and dust to travel around the planet, thus blocking

sunlight and thus, plants were unable to conduct photosynthesis, while the herbivores died from

this lack of food, and then carnivores died of starvation (Ocampo, Vajda, & Buffetaut 197).

Plants and dinosaurs are known to have gone extinct. The extinction also affected mosasaurs,

plesiosaurs, sharks, teleost fish, and mollusks. After a few years, the earth began recovering after

life returned to the submerged impact crater, and the marine creatures began to flourish. This

effectively set stage for biodiversity today because species started coming up slowly. It is still

possible for this to happen again if such an asteroid falls to earth again.

Overall, this event is among the most significant extinctions in science and world history.

Species that lived then, including dinosaurs, suffered and became extinct due to the impact of the

asteroids. The asteroid caused atmospheric changes that caused a shift in the environment that

could no longer support the species. Although the earth recovered, it still runs the risk of a

similar event if such an asteroid happens to hit the earth again, as is constantly studied.

Works Cited

Chiarenza, Alfio Alessandro, et al. "Asteroid impact, not volcanism, caused the

end-Cretaceous dinosaur extinction." Proceedings of the National Academy of Sciences

117.29 (2020): 17084-17093. https://doi.org/10.1073/pnas.2006087117

Ocampo, Adriana, Vivi Vajda, and Eric Buffetaut. "Unravelling the Cretaceous-Paleogene (KT) turnover, evidence from flora, fauna and geology." Biological processes associated with impact events (2006): 197-219. DOI: 10.1007/3-540-25736-5_9