As stated by researchers, this was due to the restoration of water circulation in the oceans.
Paleontologists at the University of California, Davis (USA) figured out how the reptiles managed just three million years to colonize the oceans, deserted after the Great extinction at the end of the Permian period.
It turned out that the animals helped the resumption of circulation of marine waters.
Approximately 250 million years ago, there have been drastic changes in the climatic face of the planet. They most likely were caused by a mighty activity of the volcanoes. In this process, the disappeared 96% of marine species. However, the efforts of experts found out that the restoration of the planet’s biosphere took a relatively short period of time on a geological scale.
To make such a claim, the scientists were able, after referring to the rocks and fossils that were collected near the lake Chaohu in China.
Experts have studied the fossils of the most ancient marine reptiles known to man. The age of these fragments is 248,81 million years. As you know, after the mass extinction chemical composition of oceanic waters has changed significantly, on the border of the Permian and Triassic periods had stopped the process of vertical mixing of water layers. This resulted in a shortage of dissolved oxygen.
However, when water circulation was restored, reptiles again widely populated oceanic space. This happened due to the fact that during the mixing of waters nutrients began to be imposed on the surface of the ocean, therefore, were the beings who were in the bottom of the food chain.