A time machine can only be obtained via creative mode. It has no purpose yet, but if you go into the items folder in the textures folder, which is in the mod folder, you will find some sprites for mysterious animal coins, dino coins and human coins which may be related to the activation and destination of the time portal in future updates. Once this new dimension is done you will be able to enter the REAL Dino days. They will create TONS of new dinosaurs to add into this dimension, many will be unique to 'The Past' which will be the name of the dimension. There will also be unique biomes and dinosaurs will move in herds. Most of the new players are trying to find out its uses, which are none yet.