Just thought I'd ressurect this thread and recommend the Fossil mod. I've pretty much only played vanilla from the start and decided to try a few mods to see what's fun and the fossil mod is great. It adds new fossil blocks which you mine and get new items, like bones and relics. You build new machines which can analyse these blocks and get dinosaur DNA from them, and then you can cultivate this DNA to create and egg, hatch the egg and you've got your own dinosaurs. You can even tame and command the dinosaurs too.
It's great fun, especially if you go mad at the start and create loads of packs of raptors all over the place. The models are really well done, and the whole things is really well thought out.
I would warn though, that since I installed it, I've been unable to create stacks of items from the furnace. If I have 2 iron ore blocks, for example, and put them into the furnace, the first will smelt fine, but the second one will just overwrite the first one, soyou're just left with one iron bar.
The way I dealt with this is to just use Invedit to edit my inventory and change the ore to bars. It's annoying, but it works.