While you're not supposed to answer an old question I believe I have a point that's not been mentioned.
First of all the typing, steel is obviously for the metal exo-skeleton but how is it bug? This could be explained by the modification but that's hard to tell. What really convinced me is that in Pokemon White the pokedex claims it was a bug. Since Kabutops isn't a bug it's almost certainly not the Pokemon that was modified.
Trivia: The Pokemon white dex states that team Plasma upgraded the canon while B2/W2 states they added it.