Primitive Magnemite?

Perhaps this thing is some kind of ancient Magnemite?

Oerstone is named after the Oersted, the CGS unit for magnetic field strength. Now you know!

Oerstone (Oersted + Stone)
Lodestone PKMN
Rock/Electric
Magnet Pull, Lightningrod
3'11"
333.4 lbs
"It manipulates rocks through some mysterious force. When it's angry, it fires lightning in random directions."
"Its pieces gyrate wildly in orbit. It would cause an explosion if two of its prongs hit each other."

HP: 58
Attack: 75
Defense: 135
Sp. Atk: 82
Sp. Def: 75
Speed: 30
Total: 455

Yeah, it's got great Defense, but can it survive an Earthquake? That...I doubt.

It has two new moves: Geo Volt (a fairly weak Electric-type Special attack with 50 base damage......but it can hit Ground-types! ) and Electro Bola (an Electric-type version of Grass Knot).

By leveling up, Oerstone can learn Tackle, Harden, Rock Throw, Rapid Spin, Spark, Magnitude, Magnet Bomb, Gravity, Rock Blast, Selfdestruct, Electro Bola, Geo Volt, Magnet Rise, Stealth Rock, Thunderbolt, Gyro Ball, Explosion, and Stone Edge.

Oerstone (c) me
Pokemon (c) Nintendo/GameFreak