The similar shapes of fast swimming marine predators are an example of:

convergent evolution

Explanation:

The similar shapes of fast swimming marine predators are an example of convergent evolution.

Convergent evolution shows how different species possess identical structures even though they evolve separately. Convergent evolution typically takes place with the organisms that are not really related.

An example of convergent evolution is the similarity that can be noticed in the wings or the flights of bats, birds, insects, etc

then that particular organisms become extinct.