There are several theories about how dinosaurs, some of the biggest and fiercest animals to roam Earth, became extinct. One prominent theory suggests that they died out after an asteroid hit Earth. Now, new research has provided more details about this asteroid impact theory.
The Dust Cloud Theory
According to a new study reported by Fox News, dinosaurs went extinct because of a huge cloud of dust caused by the asteroid impact. This cloud covered Earth’s atmosphere for 15 years, dropping the temperature by 24 degrees. Photosynthesis, the process plants use to make food and oxygen, stopped for two years.
Evidence from the Tanis Site
Scientists studied the sediment layers at the Tanis paleontology site in North Dakota, where there is evidence of the asteroid impact. Scientist Cem Berk Senel explained that the asteroid impact set off a chain of events leading to the extinction of dinosaurs. “Dust could shut down photosynthesis for such a long time that it could pose severe challenges. It could result in a chain reaction of extinction to all species in the food chain,” Senel told the Washington Post.
Impact on Earth’s Ecosystem
Scientists believe the asteroid impact led to the extinction of about three-quarters of all species living on Earth at that time. They suggest the impact created a giant dust cloud, killing plants due to lack of sunlight, causing wildfires, and releasing sulfur aerosols into the atmosphere.
The Role of Dust Particles
According to researchers, microscopic dust particles played a major role in blocking sunlight, more so than soot particles or sulfur aerosols. “The duration of darkness is really important because if, in fact, photosynthesis was shut down, and that drove extinctions, it has to be dark for a fairly substantial length of time,” David Kring, a planetary scientist not involved in the study, told the Washington Post.
Multiple Causes of Extinction
However, Kring emphasized that there wasn’t a single cause for the extinction of dinosaurs. “Each of those environmental consequences affected different parts of the world and lasted for different amounts of time. So one of the things that we understand in general, and not yet in detail, is that it’s really this potpourri of environmental effects that led to the extinctions. There’s no single silver bullet,” explained Kring.
This new research helps us understand the complex series of events that led to the extinction of the dinosaurs.