Enclosures are vital to a good park, as they keep prehistoric animals contained and safe from other mobs. Enclosures can be built out of various materials, from dirt to advanced materials such as iron and reinforced glass. Each pen should have the size and environment for each dinosaur, making a comfortable home for your animals.
"Normal" Animals and Semi-Aquatic Animals
These are enclosures for animals that do not climb or fly over walls. These include Dryosaurus, Gallimimus, Allosaurus, ect. They require a 1.5 - 2 block-high wall to keep them enclosed, but they can be taller to be safe. If you have block-breaking on, be sure you use materials that are too strong for animals to break through (Check what's as strong as iron on the Minecraft wiki) Everything in the "fences" paragraph below applies here. Make sure it has all your animal's needs inside your exhibit.
This category includes the Velociraptor and Deinonychus at the moment. These dinosaurs can climb walls, and require a ceiling or a lip(trapdoors, leaves, or a block surrounding the top of the exhibit, but one block inside). This will ensure your feathered friends are well contained in their enclosures. Make sure the block is transparent, such as a glass block or leaves, so they don't suffocate while climbing.
These mobs must be in water at all times to survive. These include Mosasaurus, Plesiosaurus, ect. You must build an aquarium or use a lake, or even a enclosed area in the open ocean. Most are aggressive when untamed and will attack you if you enter their territory.
These mobs have the ability to fly, and you need to build an aviary with no gaps, or they will fly away. They enjoy perching on trees, and you can build various viewing areas, such as a ground dome, a hanging cage, or even a glass bridge. Remember, they are protective of their territory when untamed and will attack you if you do not take safety precautions.
Feeders are important to maintain a dinosaurs hunger and keep them happy. It is advised to place the feeder on an easily accessible spot above ground, with most sides of the feeder exposed, allowing any dinosaur to fulfill their hunger. Do not work as of now, so turn off hunger in ¨Config¨ unless you would like to feed them manually.
Fencing is a bare-bones requirement for an enclosure to be usable. These rules generally apply to all terrestrial animals, but you will have to take extra precautions housing animals that climb, swim and fly. If block breaking is turned off, you can use any kind of block to contain animals, but for added realism vary the kinds of blocks you use depending on how powerful the animal is (Example, don't contain Spinosaurus with light wooden fences). If you have block-breaking on, be sure to build walls made of iron and reinforced glass/sand to contain the animals who can break blocks. You could bypass both of these if you hollow out a hole in the ground too deep for animals to break through. Depending on their use, you can use transparent materials in your fence that allow onlookers to look inside the enclosure. These include (From least visibility to most), trapdoors, leaves, slabs, fences, iron bars, stained/normal glass, and reinforced glass. These materials look best when surrounded by solid blocks. Alternatively, you can create vantage points that allow people to look over the fence, while still being far away from the animals. Building enclosures are both an art and a science, and the best fences not only keep things in and others out, but also look great. It's usually a good idea to build enclosures and buildings in a cohesive theme.
Anyone can build enclosures to be purely functional, but the best enclosures keep a habitat and theme in mind. What does this mean? It means that animals live in an environment where it looks like they belong, and your builds work together to look good. First, consider habitats. This includes plants, ground, biome, water and its depth, different kinds of stone, etc. One option is to make habitats accurate to where the animal lived. Look on the internet, or ask a friend if they're extremely knowledgeable in prehistory. If you want to be extremely accurate, use only plants that your animal lived alongside. For example, Brachiosaurus never saw flowering or deciduous trees, but T. rex lived in forests filled with them. Grass appeared in the Cretaceous period, but at the time was only found in the Southern Hemisphere. Even in the ocean, during the Late Cretaceous corals were replaced by clams! It also doesn't hurt to guess what kinds of places an animal would look good in; Parasaurolophuses look better in forests than they do on a dry desert beach. This applies to adventurous "habitats" too, though: Sarcosuchus fit better in a ruined version of New Orleans than in the desolate Arabian desert. Second, think about how the build fits in a theme. Build a temperate forest enclosure out of medieval cobblestones and logs, surrounded by Tudor architecture. A desert enclosure could be built like a Western desert ranch, or of ancient sandstone monuments, or even a stark cubist modern airport. Keeping all these things in mind, your parks, facilities and alien laboratories can look very impressive.