http://www.sciencemag.org/news/2020/11/megalodon-was-megalo-mom

The megalodon, which lived 23 million to 3 million years ago, could reach body lengths three times that of a great white shark.

Megalodon, the largest shark that ever lived, was a fierce predator in prehistoric seas, with a bite force five times as strong as today’s great white.  But it was also a wise mother, new research reveals. An analysis of megalodon teeth found from sites across multiple continents suggests these giants commonly laid their eggs in nurseries to improve their youngsters’ chances of survival, just as some modern sharks do.