Same place as you get a Gorgo. And if you don't know were that is it is the Parchment desert [Giganto heads are hard to clean so don't be sad if you fail, I only got 50 on the body and arms and got 53 on the head].
after completing the game go to parchment desert and talk to the weird man. After doing that go to the shop and buy oasis seeds. Then give them to the man. I found a Giganto head with 3 oasis seeds planted.
You find it in Parchment Desert after you pay 20k each for oasis seeds after you beat the game.
At Parchment Desert
up your but & around the corner
Aro's weakness is probably Fire type attack/large vivasaurs like Giganto.
Igno is a king trye from fossil fighters champino
If you meant Saichan, then Mt. Lavaflow in the regular Fossil Fighters. I'm not sure about Fossil Fighters: Champions.
how to get shoni arms in fossil fighters ds
in the sea
Areos is best but if you use a miraceous fossil rock it's better. Also Raja and Giganto are great team with Areos. But for legendaries I say Igno is very good with defense and ofense!
you buy it at the fossil guild
In bb base
At the BB Base
Rivet Riven
in rivet ravine