This graph plots extinction rates of marine animal families over the last 600 million years. The shaded band indicates the normal range of extinction rates, known as "background extinction." The ...

A third of sharks are at risk of extinction, too, according to the report. More than 40% of all amphibian species (that includes frogs, toads, salamanders, and newts) are threatened with extinction.

In this new study, the researchers found evidence suggesting that the evolution of humans led to the extinction of nearly 30 species of trunked animals over millions of years.