The skeleton of a fearsome 16-foot-long “top tier” marine predator from the Jurassic period is discovered by scientists.

Did ancient whales walk on four legs and move like giant otters? - Quora

Pakicetus, Georgiacetus, Phiomcetus and Remingtonocetus

Squelette partiel de Pakicetus (Éocène inférieur, Pakistan) constitué... |  Download Scientific Diagram

Top 5 Deadliest Predators of All Time - Owlcation