how the turtle's cover was made?

Sea shells, sea shells, turtles . may be products of geological changes hundreds of millions of years ago, causing the amount of calcium in the ocean floor to suddenly rise (about three times higher than today).

Professor Sean Brennan and his colleagues at the Geological Research Center in Georgia, the United States found evidence that the amount of calcium in the sea water rose very high during the late Proterozoic period (about 544 million years ago). ) to the beginning of the Cambrian period (about 515 million years ago). They argue that this transformation has enabled many soft-bodied marine species to start forming shells or hard bodies from minerals that have insoluble calcium content.

The researchers also suggested that shellfish could be formed to help these animals excrete calcium in conditions of high calcium levels that could be dangerous, and the formation of a shell may have begun. for the period to create a diversity of shapes in the group of soft-bodied marine creatures.

NGUYEN SINH