Based on data obtained from deep-sea geological drilling, some scientists believe that an unusual climate change occurred on Earth 65 million years ago, with a sudden rise in temperature. This change made it difficult for cold-blooded animals like dinosaurs, which had weak heat dissipation capabilities, to adapt to the environment, causing endocrine system disorders, especially severe damage to the reproductive system of males. As a result, dinosaurs were unable to reproduce, leading to their eventual extinction.
Another theory, while also arguing that abrupt climate change caused the extinction of dinosaurs, describes a different process. This school of thought believes that around 70 million years ago, the Arctic Ocean was completely separated from other oceans by land, and in its final days, the salty seawater gradually turned fresh due to various factors. Around 65 million years ago, the "bank" separating the Arctic Ocean from other oceans suddenly breached. Large amounts of water from the Arctic Ocean, which had become lighter due to desalination, flowed into other oceans. Because the Arctic Ocean water was very cold, this overflowing cold water formed a cold current, causing the temperature of the Earth's oceans to drop rapidly by about 20 degrees Celsius. This drop in ocean temperature severely affected the continental climate, cooling the air above the land. Simultaneously, the water vapor content in the air decreased rapidly, causing widespread drought on land. The combined effect of these climate changes on land was the extinction of the dinosaurs.
One possible way climate change caused the extinction of dinosaurs was by severely impacting their eggs. Some scientists have discovered that dinosaur eggshells tended to become thinner at the end of the Cretaceous period, before the dinosaurs' extinction, suggesting that drastic climate change played a role in the event of this mass extinction. Some paleontologists in my country have also found that dinosaur eggs from fossil sites closer to the extinction period have fewer pores in their shells than eggs from other periods, which is likely related to a colder and drier climate.
