Pelagic Prehistory for Minecraft

Extinct: Pliosaurus, Plesiosaurus, Dunkleosteus, Bawitius, Shonisaurus, Cladoselache, Prognathodon, Lepidotes, Irritator, Henodus.
Extant: Cuttlefish, Dugong
Plants/sea life: Ginkgo tree, Charnia, Sea Sponge.

Your first step is finding fossils! These are found only on the sea floor of all ocean biomes. They are buried within ancient sediment, a new building material. In these deposits you can also find a new version of coal ore that produces twice the normal amount. Next, you'll need an ANALYZER, and an INFUSER. Recipes for these machines can be found in the images tab, and by using JEI.

ANALYZER- Insert your new-found fossils into the analyzer. It will begin to process your finds and turn them into usable DNA vials. 
INFUSER- Once you have your vials, insert them along with their respective ingredient, (listed by holding shift while hovering over the vial), and watch them grow!

Now that you have your plant, egg, or pup, you can place them in the water! They will hatch fully grown. DON'T WORRY. If your animal dies it will drop itself as an item that can be replaced- no harm or foul.