You can get Ptera fossils only with Donation Points (DP). Each part will cost you 100 DP, but they'll always be rare fossils (red bones, they give you a 25 point bonus when you clean them). You get DP by cleaning a fossil rock you've cleaned before, and if it has a lower score than the one currently integrated/in storage, it gets donated. If you clean a fossil that's in storage (hasn't been revived yet), the fossil with the lower score will be donated. If you clean a fossil rock and get the same score as the fossil that's currently integrated/in storage, it gets donated.
If you meant Saichan, then Mt. Lavaflow in the regular Fossil Fighters. I'm not sure about Fossil Fighters: Champions.
You can find him at bonemoth
Treasure Lake
Petrified Woods
in sea floor cavern
You can find allo in the rainbow canyon
You take a amargo fossil from dusty dunes and super evolve it.
you can find it at hot spring heights
up your but & around the corner
at hot spring heights
well you have to find goobs
In "Fossil Fighters: Champions," you can find the Tanstro fossil primarily in the Dunes area. It is often located in various digging spots within that region. Players need to carefully excavate to uncover the fossil, which can then be revived to use Tanstro in battles.