The Doedicurus is one of the best utility dinos in Ark, and probably the best stone gathering dino available. The Doed can harvest stone from rock and metal nodes. While Doed’s don’t lay eggs, they are breedable. The Doed’s size makes it easy to store and it can be carried in the talons of Quetzals and Wyverns. If you’re planning to build in stone, the Doed is an essential addition to your dino collection!
On PS4 I tried to test it's obsidian gathering since it is "Rank 1", well all it was gathering was stone. So I went to another saying maybe something was wrong, NOPE it does not gather obsidian. Just use an Anklyo for that.