Yes, they are on extinction. In the desert dome, they take the form of rubble golems. They are extremely common as a guard for the desert titan terminal. Rubble golems have less health though so they can easily be taken out by a good velonsaur or managarmr. They give the same loot as the big one though, so get farming.
If you are unsure if a rock is a disguised golem or not, a spyglass shows their name and level even when disguised. Also, when disguised, the rocks often move slightly as you get close, re settling onto the terrain.
If you kill them using a thyla’s gnashed ability then you can harvest their body with an anky. Killed a level 95 and just got 198 stone, 114 Crystal, 134 obsidian, 123 oil, and 78 metal from it. Hope this is useful to someone!! Have a nice day!!! :)