This is the most common structure in your world. The Prehistoric Ruins will hold 4 Fossil Ores for you to mine and collect. Although beware, as a Ceratosaurus will be roaming near these structures, guarding the rewards that await you.

This is a more rare structure to find, with it being rare, if you look hard enough you will be able to find a chest that holds a special item known as Titanus DNA along with some iron ingots. Beware however, as there is usually an Omniraptor near these structures.