Scientists Figured out Why and When Cetaceans Became Big

24.05.2017

Experts examined the remains of whales stored in the National Museum of Natural History (USA) and estimated their size. The measurement of the skulls made it possible to determine the approximate length of the body. As a result, data was obtained on 63 extinct and 13 living species. It turned out that modern cetaceans are much larger than their ancestors. The increase in size occurred about 4.5 million years ago.

Scientists Figured out Why and When Cetaceans Became Big

Since this phenomenon was typical for all species, it is obvious that large animals over 10 meters long had a better chance of surviving. And most likely, this is due to the appearance of glaciers on land in the Northern Hemisphere. The concentration of nutrients in the ocean has become uneven due to the seasonal intake of thawed water, and whales have begun to migrate thousands of kilometers. In addition, they needed an effective krill filtering device. Gigantic individuals in this sense had the advantage, and the little ones gradually died out.