The only way to see or obtain a Kabutops is through trade in your instance. Perhaps someone will trade you a Kabuto or Kabutops if it's a Kabuto you will need to train it to level 40 for it to evolve to Kabutops.
Well, kabuto only turns into one another Pokemon and that's it, there is no other evolvation. Kabutos next evolvation is Kabutops, a rock/water Pokemon with amazing attack stats. Kabuto evolves into Kabutops at lvl 40
Evolutionary stones don't work on Fossil pokemon. You need to level Kabuto up to Level 40 or 42 to make it evolve. It's a pain in the butt but Kabutops is one of the best kick-butt pokemon in the gmae, next to Nidoking, Charizard, Lapras Tyranitar, Mewtwo, Golem and Raichu.
The only way to get Kabutops is to raise a Kabuto to Level 40. You can get a Kabuto by getting a Dome Fossil from underground and then taking it to the scientist in the Oreburgh Mining Museum to have it resurrected.
It evolves between lv.35-45.=D around lvl 40 or so around lvl 40 or so Kabuto evolves at level 40 evolving into a Kabutops It evolves at level 40. To find it select the dome fossil at the end of Mt. Moon.