The world's oceans are a place full of beautiful, terrifying, and even terrifyingly beautiful organisms. This is true for both our modern-day oceans and oceans throughout the history of life on Earth. In this collection, I wanted to highlight the key players of past oceans across many different periods. Many of these specimens were carnivorous, apex predators, such as Helicoprion (the buzzsaw shark that lived during the Permian Period), Dunkleosteus (an armored placoderm of the Devonian Period), Liopleurodon (short-necked pliosaurid), and Megalodon, perhaps the most famous and most frightening of any ocean organism to ever live. Other predators in the collection include a Plesiosaur skull (first appearing in the Triassic Period) and a Mosasaur (another apex predator of the Cretaceous Period). While the carnivores are the most well-known of the ancient seas, other organisms played an important role in the oceans. Included in my collection are Ammonites, a Crinoid, and a fragment of a Baenidae shell.