Everyone knows that super fossil rocks are rare. Yeah, it took me three hours to find one I was looking for. Wonderous Fossil Rocks are ok. They aren't that rare, but Miraculous fossil rocks are the cream of the crop. Rare beyond standards, and difficult to obtain, they are expensive as well. However, there is an easier way to obtain these elusive treasures. Elemental masks. For example using the red mask in Icegrip Plateau will decrease the amount of other fossils found. Also, Blue Mask in Dusty Dunes works well too.
I found like 20 Miraculous Fossil Rocks using a Blue Mask and Head mask in Mt. Krakanak. It's also a great source of dropping fossils, Happy digging!
Hope This Helps
Using elemental masks in places where you wouldn't be able to find that element of vivosaur will make it so you can only find jewel, dropping, wondrous, and miraculous fossils. Using the blue mask at Mt. Krakanak is a good method because the route is completely straight and narrow, and you're close to the dropping fossil trader.
The higher your fighter rank, the more rare fossils you can find, so the more side quests you complete, the rarer the fossil
fossil fighter R.B.P.
There is a much easier way to do this you know. It's not guarunteed, but wearing the pink mask at the pay-to-dig site at treasure lake will give you a wondrous or miraculous fossil rock or dark fossil rock (they're rarely dark because super fossils are way better) 8 times.
P.S. Apply the arms to a T-rex to have a vivosaur with the highest attack in the game. If a team is created using this T-Rex in the AZ and two Guans in the SZ, most vivosaurs are overcome with only a singly shot! Not to mention it's a compatible team!